zte wcdma npo primary02-200711 wcdma radio network planning and optimization

WO_100_E1 WCDMA wireless Network Planning and Optimization

Course Objectives：

· Understand the basic principles and composition of antenna.

· Understand the basic principles and composition of antenna.

· Understand antenna installation projects.

· Master the model selection methods of antennae, and can select

antennae reasonably according to the geographical and physical

nature of the scenario.

Reference： · Radio Technology Performance Indices and Technical White

Paper

· References of WCDMA Radio Communication System Antenna

Manual

· WCDMA Outdoor Antenna Model Selection Textbook

· Antenna Basics

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Contents

1 WCDMA network planning ...................................................................................................................... 1

1.1 Features of WCDMA Technology..................................................................................................... 1

1.1.1 Distinguishing Channels With Code ...................................................................................... 1

1.1.2 Self-infection System............................................................................................................. 2

1.1.3 Providing Multi-rate Diversified Services ............................................................................. 2

1.1.4 Soft Capacity.......................................................................................................................... 2

1.1.5 Other Features ........................................................................................................................ 3

1.2 low Chart........................................................................................................................................... 3

1.3 Description of Network Planning Process ........................................................................................ 4

1.3.1 Pre-research of Project ........................................................................................................... 4

1.3.2 Demand Analysis ................................................................................................................... 4

1.3.3 Scale Estimation and Pre-planning Emulation....................................................................... 5

1.3.4 Plan of Survey........................................................................................................................ 5

1.3.5 Site Survey, Propagation Model Test and Noise Test............................................................. 6

1.3.6 Site Filtering........................................................................................................................... 7

1.3.7 Topology Design .................................................................................................................... 7

1.3.8 Dummy Topology Selection................................................................................................... 8

1.3.9 Report Submission ................................................................................................................. 8

1.4 Reports of Network Planning............................................................................................................ 8

2 WCDMA Coverage Estimation................................................................................................................. 9

2.1 Radio Propagation Model ................................................................................................................. 9

2.1.1 Free Space Propagation Loss ................................................................................................. 9

2.1.2 Propagation Model............................................................................................................... 10

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2.2 Link Budget .....................................................................................................................................12

2.2.1 Basic Link Budget Parameters..............................................................................................13

2.2.2 Unlink Budget.......................................................................................................................22

2.2.3 Uplink/Downlink Balance ....................................................................................................23

2.3 Coverage Scale Estimation ..............................................................................................................24

2.3.1 Calculation of BS Coverage Radius .....................................................................................24

2.3.2 Calculation of BS Coverage Area.........................................................................................25

2.3.3 Scale Calculation ..................................................................................................................26

3 WCDMA Capacity Estimation ................................................................................................................27

3.1 Capacity Estimation Flow................................................................................................................27

3.2 Estimation Method of Hybrid Service Capacity..............................................................................27

3.2.1 Equivalent Erlang Method....................................................................................................28

3.2.2 Post Erlang-B Method ..........................................................................................................29

3.2.3 Campbell Method .................................................................................................................30

3.3 Uplink Capacity Estimation.............................................................................................................33

3.3.1 Load Analysis for Uplink......................................................................................................33

3.3.2 Uplink Capacity and Scale Estimation .................................................................................36

3.4 Downlink Capacity Estimation........................................................................................................38

3.4.1 Analysis of Downlink Load ..................................................................................................38

3.4.2 Downlink Capacity and Scale Estimation.............................................................................41

4 Survey of Network Planning....................................................................................................................43

4.1 Overview .........................................................................................................................................43

4.2 Selection of Base Site ......................................................................................................................43

4.2.1 Method of Selecting Site.......................................................................................................43

4.2.2 Policy of Selecting Site.........................................................................................................47

4.2.3 Mitigation in Site Selection ..................................................................................................48

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4.3 Collection of WCDMA Networking Planning Data........................................................................ 51

4.3.1 Overview.............................................................................................................................. 51

4.3.2 Project Information .............................................................................................................. 51

4.3.3 Categorization of Coverage Area ......................................................................................... 52

4.3.4 Collection of Existing Resources ......................................................................................... 53

4.3.5 Information of Important Transportation Line ..................................................................... 54

4.3.6 Information of Important Buildings in Urban Areas............................................................ 54

4.3.7 Information of Sites on the Existing Network...................................................................... 54

4.4 Identification of Base Model........................................................................................................... 55

4.4.1 Overview.............................................................................................................................. 55

4.4.2 Requirement Analysis .......................................................................................................... 55

4.5 Introduction to Base Stations .......................................................................................................... 57

4.5.1 Macro BS ............................................................................................................................. 57

4.5.2 Micro Cell Base Station ....................................................................................................... 60

4.5.3 Remote Radio Station........................................................................................................... 62

4.5.4 Repeater ............................................................................................................................... 63

4.5.5 Others................................................................................................................................... 65

4.6 Networking Schemes in Typical Surroundings ............................................................................... 66

4.6.1 Basic Coverage in Urban Areas and Traffic-Dense Areas.................................................... 66

4.6.2 Coverage in Suburb and Countryside................................................................................... 67

4.6.3 Coverage in Particular Surroundings ................................................................................... 68

4.6.4 Coverage along Freeway and Railway................................................................................. 69

5 Tools using in the Survey of Network Planning..................................................................................... 71

5.1 GPS Principle & Application .......................................................................................................... 71

5.1.1 GPS Structure....................................................................................................................... 71

5.1.2 GPS Principles ..................................................................................................................... 71

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5.1.3 Name and Function of the GPS Panel Keys .........................................................................71

5.1.4 Basic Operations...................................................................................................................72

5.1.5 Basic Information .................................................................................................................74

5.1.6 Navigation Operation............................................................................................................77

5.1.7 Function Setting....................................................................................................................78

5.1.8 Performance Specifications ..................................................................................................80

5.2 Principle and Application of a Laser Rangefinder...........................................................................81

5.2.1 Name and Function of the Panel Keys on a Laser Rangefinder ...........................................81

5.2.2 Operation Description...........................................................................................................82

5.2.3 Function ................................................................................................................................89

5.2.4 Technical Parameters ............................................................................................................98

5.2.5 Signal ....................................................................................................................................99

5.2.6 Maintenance..........................................................................................................................99

5.3 Use and Selection of Digital Camera.............................................................................................100

5.3.1 Brief Introduction ...............................................................................................................100

5.3.2 Specifications......................................................................................................................100

5.4 Compass Use Specifications..........................................................................................................102

5.4.1 Structure of a Compass .......................................................................................................102

5.4.2 Basic Operations.................................................................................................................103

5.4.3 Precautions..........................................................................................................................105

6 The Propagation model test and correction..........................................................................................107

6.1 Propagation Model Test Operation Process...................................................................................107

6.2 Test Procedures..............................................................................................................................108

6.2.1 Equipment Preparation .......................................................................................................108

6.2.2 Testing Site Selection..........................................................................................................108

6.2.3 Testing Route Selection ......................................................................................................111

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6.2.4 Test Environment Preparations .......................................................................................... 114

6.2.5 Test Result Processing........................................................................................................ 121

6.3 WCDMA Propagation model tuning............................................................................................. 126

6.3.1 Inputs for Propagation model tuning.................................................................................. 126

6.3.2 WCDMA Propagation model tuning Process..................................................................... 127

6.3.3 Preprocessing Test Data ..................................................................................................... 128

6.3.4 Selecting Propagation model.............................................................................................. 131

6.3.5 Transmission Model Tuning............................................................................................... 147

6.3.6 Propagation Model Tuning Result...................................................................................... 154

7 The Principal and Selection of Antenna............................................................................................... 155

7.1 Overview of Base Station Antennae.............................................................................................. 155

7.1.1 Development of Industry Technologies of BS Antennae ................................................... 155

7.1.2 Technical and Market Situations of Chinese Antenna Enterprises..................................... 155

7.1.3 Competitive Advantages of Foreign Antenna Enterprises.................................................. 156

7.1.4 Development Direction of Antenna Industry ..................................................................... 156

7.2 Principles of Antenna Radiation.................................................................................................... 157

7.2.1 Electromagnetic Wave Radiation ....................................................................................... 157

7.2.2 Symmetrical 1/2 wavelength Dipole .................................................................................. 158

7.3 Internal Structure and Classification of Common BS Antennae and Indoor Antennae................. 159

7.3.1 Directional Patch Dipole BS Antennae .............................................................................. 159

7.3.2 Omni Serial Feeding BS Antennae..................................................................................... 162

7.4 Concept and Significance of Antenna Technical Parameters ........................................................ 163

7.4.1 Gain of Antenna ................................................................................................................. 163

7.5 Antenna Radiation Pattern............................................................................................................. 164

7.6 Lobe Width.................................................................................................................................... 166

7.6.1 Horizontal Lobe Width....................................................................................................... 167

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7.6.2 Vertical Lobe Width ............................................................................................................168

7.7 1.1 Working Frequency Range of the Antenna ..............................................................................168

7.8 Polarization Modes ........................................................................................................................169

7.9 Downtilt Mode...............................................................................................................................170

7.10 Front/Back Ratio of Antenna .......................................................................................................171

7.11 Input Impedance of Antenna, Zin ................................................................................................172

7.12 Antenna VSWR ...........................................................................................................................172

7.13 Side Lobe Suppression and Zero Filling......................................................................................173

7.14 IM 3rd Order................................................................................................................................174

7.15 Isolation between Ports................................................................................................................174

5.4 Radio Parameters of Antenna ........................................................................................................175

7.16 Antenna Radiation Pattern ...........................................................................................................175

7.17 Gain of Antenna...........................................................................................................................176

7.18 Input Impedance of Antenna, Zin ................................................................................................177

7.19 Antenna VSWR ...........................................................................................................................178

7.20 Antenna Polarization....................................................................................................................178

7.21 Front/Back Ratio of Antenna .......................................................................................................179

7.22 Azimuth Angle of Antenna ..........................................................................................................179

7.23 Antenna Height ............................................................................................................................180

7.24 Downtilt Mode.............................................................................................................................180

5.7 Classification of Antenna...............................................................................................................181

7.25 Antenna Parameter Examples ......................................................................................................181

7.26 Antenna Model Selection.............................................................................................................183

7.27 Classification of Antenna Application Scenarios.........................................................................184

7.27.1 High-density Urban Areas ................................................................................................184

7.27.2 General Areas (Cities and Towns) ....................................................................................184

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7.27.3 Suburb (Township) and Countryside................................................................................ 184

7.27.4 Railways and Express Highways (Highways).................................................................. 184

7.27.5 Scenery Spots................................................................................................................... 185

7.28 Antenna Model Selection ............................................................................................................ 185

7.28.1 Basic Principles of Antenna Model Selection .................................................................. 185

7.28.2 High-density Urban Areas................................................................................................ 186

7.28.3 General Urban Areas........................................................................................................ 188

7.28.4 Suburb, Twonships, and Countryside............................................................................... 189

7.28.5 Railways and Express Highways (Highways).................................................................. 190

7.28.6 Scenery Spots................................................................................................................... 192

7.29 Type Library of WCDMA Antennae........................................................................................... 194

7.29.1 Collection of WCDMA Outdoor Omni Antennae............................................................ 194

7.29.2 Collection of WCDMA Outdoor Directional Antennae ................................................... 198

7.29.3 Collection of WCDMA Indoor Omni Antennae............................................................... 200

7.29.4 Collection of WCDMA Indoor Directional Antennae...................................................... 202

7.30 Antenna Installation Specifications............................................................................................. 204

7.31 Antenna Installation .................................................................................................................... 204

7.31.1 Pole Installation................................................................................................................ 205

7.31.2 Tower Installation Mode .................................................................................................. 205

7.32 BS Antenna Structure and Connection........................................................................................ 206

7.33 BS Antenna Installation............................................................................................................... 208

7.33.1 Considerations.................................................................................................................. 208

7.33.2 Outdoor Directional Antenna Installation ........................................................................ 209

7.33.3 Outdoor Omni Antenna Installation ................................................................................. 211

7.33.4 Indoor Antenna Installation.............................................................................................. 211

7.33.5 Jumper Installation ........................................................................................................... 213

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7.33.6 Lightning Arrester Installation..........................................................................................214

7.33.7 Grounding kit Installation.................................................................................................216

7.34 Antenna Feeder System Debugging.............................................................................................217

7.34.1 Prerequisites......................................................................................................................217

7.34.2 Debugging Procedure .......................................................................................................218

7.35 Connector Sealing........................................................................................................................218

8 WCDMA Radio Network Optimization Process and Technology ......................................................219

8.1 Service Consideration of Network Optimization...........................................................................219

8.2 Reasons for Network Optimization ...............................................................................................219

8.3 Types of Network Optimization.....................................................................................................220

8.3.1 Engineering Optimization...................................................................................................220

8.3.2 O&M Optimization.............................................................................................................220

8.4 Optimization Workflow .................................................................................................................221

8.5 Optimization Steps.........................................................................................................................223

8.5.1 Preparation..........................................................................................................................223

8.5.2 Frequency Spectrum Scanning (Optional)..........................................................................224

8.5.3 Calibration Test (Optional) .................................................................................................224

8.5.4 Network Data Collection ....................................................................................................225

8.5.5 Data Analysis ......................................................................................................................237

8.5.6 Parameter Check (Optional) ...............................................................................................256

8.5.7 Problem Localization..........................................................................................................257

8.5.8 Formulation of the Optimization Plan ................................................................................261

8.5.9 Implementation of the Optimization Plan...........................................................................264

8.5.10 Optimization Effect Verification.......................................................................................264

8.5.11 Project Acceptance............................................................................................................265

8.5.12 Document Archiving.........................................................................................................265

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1 WCDMA network planning

1.1 Features of WCDMA Technology

The features of WCDMA technology determine the characteristics, difficulties, and

solutions of WCDMA network planning. Therefore, we use the features of WCDMA

technology as the clue to introduce the features of WCDMA and the related

characteristics of network planning.

1.1.1 Distinguishing Channels With Code

In the WCDMA system, all the subscribers in each carrier share the frequency, time,

and power resources. Feature codes (scrambles and channel codes) are used in statistic

processing of signals to distinguish channels. That is the so-called CDMA technology.

A channel in the WCDMA system does not occupy a band or time segment alone. The

transmitting end sends signal sequences according to the patterns of feature codes. The

receiving end measures and calculates the signals received according to the same

patterns of feature codes. If the feature code selected has good self-correlation and

cross-correlation, when there is signals for the local channel, the statistic result will be

expressed as high peak, and the effect of other channels will be attenuated. Thus, the

channels in the system can be distinguished. Therefore, in the WCDMA system, there

is feature code planning instead of frequency planning.

A WCDMA channel is composed of three parts, namely data stream, channel code

sequence, and scramble sequence. The channels must have at least one different

channel code and scramble. For the forward channels, different scrambles are used to

distinguish different cells. The channels in a cell are distinguished by different channel

codes. To ensure the isolation of cells, adjacent cells are not allowed to use the same

scramble. Pay attention to this point during network planning. Because there are

abundant code resources in reverse links, the scramble of each subscriber is different.

Thanks to CDMA and QPSK modulation technology, WCDMA systems have higher

spectrum utilization than analog systems and GSM systems. Under the same condition,

the CDMA system bears much more subscribers.


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1.1.2 Self-infection System

Because the channels of the WCDMA system share the same frequency, time, and

power resources, the channels are isolated by the orthogonality of the feature codes

measured. However, the orthogonality of the feature codes is not good enough. As a

result, the channel isolation in the WCDMA system is not as good as that in FDMA and

TDMA. In addition, the more the channels are used, the stronger the interference from

other channels will be. Therefore, when the link quality is guaranteed, the transmit

power must be as low as possible. It makes the power planning an important part in

WCDMA network planning.

1.1.3 Providing Multi-rate Diversified Services

The WCDMA system can provide flexible and diversified services to subscribers. That

is an important feature of WCDMA. Under the same transmission environment, the

WCDMA is requested to provide different transmission rates, for example, it can

provide 144kbps in high-speed moving, 384kbps in walking condition, and 2Mbps

indoors. The WCDMA system also supports variable rate services, mixed services,

high speed data packet services (multimedia services), and uplink/downlink rate

asymmetric services (Internet access). Considering the service expansion in the future,

the WCDMA system also provides large capacity and data bearer capability with

flexible rate matching. To describe the QoS of the above services, parameters such as

data rate, BER, transit delay, and delay jitter are defined.

In conclusion, the single Erlang model cannot accurately describe the service demands

of subscribers in the WCDMA system. A more complicated service model must be

used.

1.1.4 Soft Capacity

The system capacity refers to the maximum number of subscribers that the system

supports at the same time.

The capacity of a WCDMA system is measured by two aspects, hard capacity and soft

capacity. The hard capacity refers to the number of channels that the Node B allocates

to each cell (it is determined by the number of baseband channels and frequency

resources). Same as the 2G system, it determines the maximum number of calls that a

cell can handle at the same time.

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The limit of soft capacity depends on the self-infection feature and the support of

diversified services of the CDMA system. The system can deny the access of new

subscribers to reduce interference and ensure QoS. In the same way, the system may

permit the application of low-rate services and reject the high-rate services for the

consideration of resources. When the network traffic is heavy, the system may decrease

the quality of certain service to reduce resource occupation. All of these should be

expressed by system soft capacity. The number of subscribers allowed to access due to

interference or limited power, or the total data throughput ratio is not fixed. It is closely

related to radio environment, and service composition and ratio. With the development

of ASIC technology, the system processing capability is no longer the bottleneck of

capacity. The soft capacity ultimately determines the system capability.

To operators, the benefits of soft capacity is that it can balance the QoS and system

capacity within a certain degree, and dynamically adjust the ratio of various service

based on the maximum economic effect. However, the soft capacity causes difficulty in

capacity planning during network planning. In the WCDMA system, the capacity

planning is the most difficult step.

1.1.5 Other Features

Other technology features of the WCDMA system may also affect the network

planning, for example, the soft handover. The soft handover can bring extra gain to the

system and expand coverage. New technologies such as antenna diversity, intelligent

antenna, and multi-user detection will enhance system performance. If these

technologies are used in the system, the possible influence caused by these factors must

be considered during network planning.

1.2 low Chart

The following figure shows the process of network planning.


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Fig. 1.2-1 Network Planning Flowchart

1.3 Description of Network Planning Process

1.3.1 Pre-research of Project

Upon the request of the operator, ZTE engineers (M&S personnel and network

planning engineers) should reach an agreement with the operator on network planning

process and working interface. The operator should provide necessary data for network

planning. The network planning can be started only after both sides sign on the

contents mutually agreed.

1.3.2 Demand Analysis

Adequate communication before network planning is essential to the subsequent work.

Prior to network planning, collect the basic information of the Node B in current

network and nail down the resources that the operator can provide, such as electronic

map, transmission resources, and equipment room conditions.

According to the requests of the operator, determine the planning of the coverage area

and corresponding subscriber density distribution, the planning of service areas, and

the target of the network planning.


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Analyze customer demands according to the requests of the operator. Learn the culture

and physiognomy of the area to be planned, explore the traffic distribution, and provide

the planning strategy that meets the coverage, capacity, and QoS requested by the

operator.

Conduct field survey in the key coverage area with accompany of the operator. Use

GPS to learn the location and area of the coverage field. Use the traffic distribution

data of the current network to guide the planning of the network to be constructed.

According to the Node B information provided, make good preparation for emulation.

In the stage of demand analysis, submit XXX (service area name) Network Planning

Requirements and Data Collection Sheet and 3G Network Planning Requirements and

Assessment Sheet.

1.3.3 Scale Estimation and Pre-planning Emulation

After estimating the network scale of the service area, determine the number of Nodes

B and the density of Node B. Use the special emulation software to verify the

estimated result of the network scale.

Through emulation, verify whether the number of Nodes B and the density of Node B

can meet the requirements of system coverage and capacity, and whether the mixed

services can meet the QoS.

The emulation not only verifies the number and density of Nodes B but also provides

Node B layout as well as the approximate area and location of the pre-selected site of

Nodes B.

Combine the pre-planning emulation results with the results of the demand analysis,

and prepare a complete planning report.

Output Report on XXX (service area name) Network Pre-planning.

1.3.4 Plan of Survey

Based on the results of emulation and the field survey period requested by the operator,

obtain the workload of the survey.

According to the workload of the survey, make the survey plan, determine the leader

and members of the field survey team, settle down the start time and end time, and

prepare the equipment for field survey.


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Assign the survey task to the leader of the field survey. The leader of the filed survey

should submit the XXX (service area or pilot network name) Survey Plan. The leader

of the filed survey should report the survey progress of each day in the Daily Report on

XX (service area name) Survey Progress. With the daily report, the home office can

learn the progress of the survey and provide necessary HR and material support in

time.

1.3.5 Site Survey, Propagation Model Test and Noise Test

The noise test is unnecessary for the use of legal frequency. However, to ensure the

network performance and detect the possible interference in time, noise test can be

performed on the sites selected according to the Specification of Noise Test in Network

Planning. If noise test is requested, output the Report on Noise Test in XXX (service

area name).

It must be clearly declared in the report that the noise test is not the specialty of ZTE,

and the equipment used is not the special equipment for noise test. Therefore, if

interference is detected, the interference exists. However, due to the factors such as

directional property, time, and test height of the interference, it does not mean the

interference does not exist if no interference is detected.

Conduct noise test during the site survey. The test results can be attached to the site

survey sheet. Noise test report is not required.

According to the Specification of Propagation Model Site Selection, the emulation

owner selects the site for the test of propagation model. The emulation test site is

similar to the planned site. The survey engineers take photons and collect radio data at

the test sits selected by the emulation owner. The test engineers determine the test paths

and conduct the test according to the Specification of Selecting the Paths for

Propagation Model Test. Based on the correction model of the electrical measurement

data, the emulation engineers obtain the propagation model under the environment of

the planned area.

Determine the propagation model test environment as follows: dense urban area,

ordinary urban area, suburb and town, and rural area.

Output Propagation Model Test Site Survey Report, Propagation Model Test Report,

and Propagation Model Correction Report.

Site survey of the planned area


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The site survey is an important part of the network planning.

The survey engineers must conduct site survey and collect data carefully to ensure the

validity and accuracy of the survey data. The site survey is essential to the network

emulation and construction as well as the network optimization.

Select the sites for field survey: take the site survey of China Mobile as an example.

Select the sites provided according to the field survey results and emulation. Select the

proper site meeting the requirements of WCDMA networking, and build up network

structure on it.

Plan the site survey: For China Tietong and China Netcom that cannot provide sites for

field survey, the survey engineers should find more than three candidate sites about 50

m around the major coverage area after determining the planned area. The candidate

sites must comply with the site selection specification. Select the sites for field survey

from the candidate sites by the means of emulation.

The survey owner should assign a person to complete the XXX (service area name)

Node B Survey Sheet, ensuring that the survey sheet is filled and the survey data is

checked on a daily basis. At the end of the survey, the survey owner submits a survey

report and summarizes the survey completed.

1.3.6 Site Filtering

According to the field survey results, test results and pre-planning emulation results,

select the sites. For the site that cannot be determined, provide the information of

several candidate sites to the home office for analysis and decision-making.

1.3.7 Topology Design

The task of this phase is to determine the type and network structure of the sites

selected. Determine the type of the site according to the requirements of coverage and

capacity, and then design a reasonable network topology. When designing the site

distribution, select network units according to the factors such as topography,

physiognomy, coverage, capacity, and equipment room conditions. The common

network elements include macro cell, micro cell, remote deploy of RF module, and

repeater. These NEs will bring good effect when applied in network construction.


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1.3.8 Dummy Topology Selection

The emulation engineers enter the data collected in the site survey in the emulation

software, perform emulation of the candidate solutions, and then select the best

solution.

1.3.9 Report Submission

The project owner submits the final network planning and design report according to

the site survey report, propagation model correction test results, and emulation results.

1.4 Reports of Network Planning

The following reports are output during network planning:

1. XX (service area name) Network Planning Requirements Analysis Report

2. XXX (service area name) Pre-planning Emulation Report

The emulation results can be attached to the pre-planning report.

3. XXX (service area name) Survey Plan

It contains the members of the survey team and the preparation of equipment.

4. Statement of XXX (service area name) Survey

After discussing with the operator, the survey owner submits this document

before the site survey. This documents describes the actual survey tasks in the

site survey.

5. Daily Report on XXX (service area name) Survey

6. XXX (service area name) Survey Report

The summary report submitted after the site survey is completed. The survey

sheet can be attached to the report.

7. Report on Noise Test in XXX (service area name)

If the operator requests the report, submit it. If not, the report can be submitted

as an attachment of the survey report.

8. XXX (service area name) Radio network Planning Report

Use the emulation tool to select the site from the candidate sites.

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2 WCDMA Coverage Estimation

2.1 Radio Propagation Model

2.1.1 Free Space Propagation Loss

Because of propagation path and landform interference, propagation signals are

decreased, which is known as propagation loss. In the space propagation, many factors

enter into radio wave loss, including ground absorption, reflection, refraction and

diffraction. In the case that radio wave is propagated in free space (homogeneous

medium with isotropy, imbibition and electric conductivity as zero), the above factors

are uncertain. However, it does not mean that there is no propagation loss of radio

wave in free space. After radio wave is propagated for a certain distance, it may also be

attenuated due to radiant energy diffusion (also called attenuation or loss).

When the transmitter whose transmission power is Pt eradiates radio signals through

isotropy antenna with gain as Gt, the signal power density Sr is:

24 d

GtPtSr π

⋅=

The signal power Pr received by the antenna with gain as Gr is:

ArSr ⋅=Pr

Where, Ar stands for the effective receiving area of antenna,

πλ

4

2⋅= GrAr

then, ( )2

2

4Pr

d

GrGtPt

⋅⋅⋅⋅=

πλ

Pt refers to the power from transmitter to transmit antenna.

λ refers to the electromagnetic wave length.

d refers to the distance between transmit and receive antennas.

Gt refers to the transmit antenna gain.

Gr refers to the receive antenna gain.


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The propagation loss is defined as the ratio of power from transmitter to transmit

antenna to power received by receive antenna:

( )2

24

Pr λπ

⋅⋅⋅==

GrGt

dPtLoss

Path loss is measured by dB, then space propagation loss (Loss) is:

( ) ( ) ( )GrGtd

GrGt

dLoss lg10lg10

4lg20

4lg10 2

2

−−

=

⋅⋅⋅=

λπ

λπ

Propagation loss of free space (Free Loss) is:

=λπd

Loss4

lg20

If λ and d are measured by Km and f is measured by MHz, the common

formula is:

fdFreeLoss lg20lg2044.32 ++=

From the above formula, we can see that the larger the distance (d) between transmit

antenna and receive antenna, and the larger the radio wave frequency (f), the larger the

free space loss. When d or f is doubled, the propagation loss of free space will be

increased by 6 dB.

2.1.2 Propagation Model

While planning and constructing a mobile communication network, you have to make

detailed study about electric wave propagation features and field strength prediction

before determining frequency band, frequency allocation and radio wave coverage,

calculating communication probability and inter-system electromagnetic interference,

and finally defining radio equipment parameters. The radio propagation model is a

mathematic formula of such variables as radio propagation loss and frequency, distance,

environment and antenna height concluded by theory study and practical test. In the

radio network planning, the radio propagation model presents the designer an

approximate propagation effect in the practical propagation environment to estimate

the space propagation loss. Therefore, the propagation model veracity determines

whether the cell planning is reasonable.

Radio propagation environments on the earth surface diversify a lot and propagation

models in different propagation environments are differentiated a lot, too. Therefore,


11111111

the propagation environment plays an important role in setting up a radio propagation

model. The propagation environment in a special region consists of the following

factors:

Terrains (mountains, hills, plain or water area)

Number, height, distribution and material features of buildings

Vegetation features

Weather conditions

Natural or man-made electromagnetic noise

Working frequency of system

Movement of mobile station

Propagation model is usually classified into outdoor propagation model and indoor

propagation model. The frequently-used models are shown in Table 2.1-1.

Table 2.1-1 Common Propagation Models

Model Name Frequency Range

Okumura-Hata 150 MHz–1500 MHz macro cell prediction

Cost231-Hata 150 MHz–2000 MHz macro cell prediction

Cost231 Walfish-Ikegami 800 MHz–2000 MHz micro cell prediction

Keenan-Motley 900 MHz and 1800 MHz indoor environment prediction

General model 150 MHz–2000 MHz macro cell prediction

The Cost231-Hata model and the General model used in the network planning software

Aircom are described below.

The Cost231-Hata model is applicable for 150 MHz–2000 MHz macro cell prediction.

The urban path loss value can be worked out with the following approximate analysis

formula:

( ) mmbb CAhdhhfPathloss +−−+−+= lglg55.69.44log82.13lg9.333.46

Where, f refers to carrier, unit: MHz, applicable for 150 MHz–2000 MHz;

bh refers to BS antenna height, unit: m, effective height 30 m–200 m;

d refers to the distance from mobile station to antenna, unit: Km;

mAh refers to mobile station antenna height correction factor;


12121212

mC refers to city center correction factor, 3 dBm for large cities and 0 dBm for

middle- and small-size cities.

In practical radio propagation environment, topographical features shall also be taken

into account. The planning software Aircom does make some improvements by

considering the topographical impacts in practical environment on the electric wave

propagation, and thus guarantee the accuracy of coverage prediction result in a better

manner.

The model is expressed as below:

Path loss = k1 + k2log(d) + k3Hms + k4lg(Hms) + k5lg(Heff) + k6log(Heff)log(d) +

k7(diffraction loss) + clutter loss

d refers to the distance from mobile station to BS antenna, unit: Km;

Heff refers to the effective height of BS transmit antenna, unit: m;

Hms refers to the height of mobile station antenna, unit: m;

diffraction loss refers to dispersion loss;

clutter loss refers to topographical feature loss correction factor.

To analyze the electric wave propagation of different regions and different cities, the K

value may vary with different topographical features and different city environments.

In practice, you need to determine the K value of different regions, cities and areas

through propagation model correction.

2.2 Link Budget

Link budget is the precondition of coverage planning. Calculation of the maximum

allowed loss of services can be made to get the coverage radius of cell in a certain

transmission model, so as to determine the BS scale under the continuous coverage

conditions. Generally, link budget shall be made in two directions of uplink (from MS

to BS) and downlink (from BS to MS). In addition, uplink/downlink balance shall be

implemented. The coverage planning is generally calculated based on the maximum

radius that the MS can reach (that is, uplink budget). That is because many uncertain

factors (such as number of subscribers that are simultaneously connected, subscriber

distribution, and subscriber rate) affect the forward coverage radius, which makes the

calculation complicated. In general cases, the BS power can satisfy the coverage


13131313

requirement. That is, the coverage is uplink limited. Table 2.2-1 shows the basic

algorithm of link budget.

Table 2.2-1

Parameter Symbol Procedure

Transmitter power (dBm) A

Transmitting antenna gain (dBi) B

Transmitting-end human body loss (dB) C

Transmitting-end feeder loss (dB) D

Transmitting-end effective radiation power (dBm) E E=A+B-C-D

Thermal noise density (dBm/Hz) F

Thermal noise (dBm) G G=F+10*LOG(3840000)

Receiver noise coefficient (dB) H

Receiver noise (dBm) I I=G+H

Interference margin (dB) J

Service bit rate (kbps) K

Processing gain (dB) L L=10*LOG(3840/K)

Eb/No (dB) M

Receiver sensitivity (dBm) N N=I+J-L+M

Receiver antenna gain (dBi) O

Receiver feeder loss (dB) P

Receiving-end human body loss (dB) Q

Power control margin (dB) R

Soft handoff gain (dB) S

Shadow fading margin (dB) T

Penetration loss (dB) U

Maximum allowed path loss (dB) V V=E-N+O-P-Q-R+S-T-U

2.2.1 Basic Link Budget Parameters

This section describes basic parameters of the WCDMA link budget.

1.Transmitter power:

BS transmitting power:

The maximum transmitting power of BS is 43 dB. The power of the Dedicated

CHannel (DCH) accounts for 63% of the total power. Table 2.2-2 shows the

power distribution of all channels:


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Table 2.2-2 Power Distribution of Channels

Power (dBm) Power (W) Proportion

Max Tx Power: 43.0 20.0 100.00%

Pilot Power: 33.0 2.0 10%

PCCPCH(BCH): 30.0 1.0 5%

SCCPCH(FACH): 30.0 1.0 5%

SCCPCH(PCH): 30.0 1.0 5%

AICH: 26.0 0.4 2%

PICH: 26.0 0.4 2%

P-SCH: 29.0 0.8 4%

S-SCH: 29.0 0.8 4%

DCH 41.0 12.6 63%

The BS transmitting power is a system parameter, different for individual services. It

shall be determined in accordance with service type and service coverage.

MS transmitting power:

During link budget, suppose the maximum transmitting power of UE data

service to +21 dBm and that of voice service to +21 dBm.

Tips:

The BS transmitting power is a system parameter, different for individual services. It

shall be determined in accordance with service type and service coverage. In the

network optimization process, optimization engineers shall adjust power distribution to

all channels in accordance with network quality and service requirement to provide the

whole network with the optimal performance.

2. Human body loss

It is generally 3 dB for voice service and 0 dB for data service.

3. Antenna gain

It is generally 0 dB for the UE.

During link budget, suppose the directional antenna gain of the BS to 17 dBi and

the omni-directional receiving antenna gain to 11 dBi. In practice, different

antennas can be selected in accordance with different region types and coverage

requirements.

4. Feeder loss


15151515

It includes the loss of all feeders and connectors between the equipment top and

the antenna connector. For a feeder of 30-40 meters long, suppose the total

feeder loss to 4 dB (including the connector loss) during link budget. For a

feeder of 40-50 meters long, suppose the total feeder loss to 5 dB (including the

connector loss) during link budget.

The feeder loss may decrease the BS receiving level and shorten the coverage

radius. Tower amplifiers can be used to make up for the feeder loss on the

uplink.

5. Eb/No

In the GSM system, the Signal-to-Noise ratio (S/N) is used to describe the

anti-interference capability of useful signals. When S/N matches certain

conditions, the receiver can demodulate useful signals. In the WCDMA system,

however, useful signals are submerged in the noise. So S/N cannot be used to

reflect the signal quality sufficiently. Eb/No serves as the reference of signal

quality in the WCDMA system.

Eb/No indicates the demodulation threshold of the receiver, that is, energy per

bit divided by the noise power spectrum density.

Eb indicates the signal energy per bit, that is, Eb = S/R where S indicates signal

energy and R indicates service bit rate.

No indicates the noise power spectrum density, that is No = N/W where W

indicates bandwidth (3.84 M) and N indicates noise (total receiving power

except the signal itself).

Eb/No =

NW

RS

= RW

NS × = PGN

S ×

PG indicates the processing gain. As an important index of the spread spectrum

system, it reflects the amplitude of valid signals increased by the spread

spectrum technology at the demodulation end.

NS is similar to IC in the GSM system.

In the unit of dB, Eb/No = S(dBm) – N(dBm) + 10lg(W/R).

The value of Eb/No is related to the receiving/transmitting diversity of mobile


16161616

equipment, multi-path channel condition, and service type.

Table 2.2-3 and Table 2.2-4 show the uplink/downlink Eb/No values of different

services under different multi-path channel conditions.

Table 2.2-3 Uplink Eb/No Value

UL Eb/No (dB) Urban Area Suburb Area

Service type Static TU 3km/h TU 50km/h RA 3km/h RA 50km/h RA 120km/h

AMR 12.2k 4.1 4.2 6.4 4.1 6 6.4

CS 64K 2.5 2.87 4.5 2.8 5.2 5.2

PS 64K 0.9 1.6 4.5 2.7 5 4.9

Table 2.2-4 Downlink Eb/No Value

UL Eb/No (dB) Urban Area Suburb Area

Service type Static TU 3km/h TU 50km/h RA 3km/h RA 50km/h RA 120km/h

AMR 12.2k 7.2 7.7 7.1 8.5 8.4 7.2

CS 64K 7.1 7.7 6.7 8.8 8.2 7.1

PS 64K 6.4 7.4 6.2 8 7.8 6.4

PS 128K 5.7 6.4 5.5 7.3 7.3 5.7

PS 384K 6.4 8 5.9 7.7 7.7 6.4

6. Interference margin

Interference margin = )1lg(lg10 η−∗− , where η indicates the cell load.

The WCDMA system is of self-interference, and its coverage is closed related to

the system capacity. At earlier network stages, little traffic results in low value of

interference margin. As the traffic load increases, the interference margin

becomes larger and the BS coverage shrinks. With regard to link budget,

therefore, it is necessary to select the maximum uplink load in accordance with

the estimated traffic increasing trend to ensure good coverage.

The value of interference margin in the uplink budget depends on the capacity

requirement in the network design. The interference margin is 3 dB when the

load is taken 50% from the dense urban area or a cell in the urban area, it is 2.2

dB when the load is taken 40% from the suburb area, and it is 1.5 dB when the

load is taken 30% from the rural area.

For the downlink, the relationship between load and interference still exists. The


17171717

interference margin shall be determined by emulation because it is hard to make

the theoretic calculation.

7. BS receiving sensitivity

BS receiving sensitivity indicates the minimum receiving level that the service

channel requires to guarantee the decoding requirement with certain

communication qualities.

From the above deduction of Eb/No:

S(dBm) = Eb/No(dB) + N(dBm) - 10lg(W/R).

N indicates the total noise that the BS receives, that is, N = Noise + Nf + IM.

In the formula:

Noise indicates the thermal noise, caused by electronic thermal movements in

the conductor. It is generated between antenna and receiver as well as in the

damaged component coupler of level 1 of the receiver. In most of

communication systems, the power spectrum density is the same at the fixed

frequency point because the noise bandwidth is far larger than the system

bandwidth. From the DC to the frequency of 1012 Hz, therefore, the noise power

generated by the thermal noise source is the same per unit bandwidth. The

calculation formula of power is:

Noise = KTW (in the unit of W)

K indicates a Boltzmann constant, namely 1.38*10-23J/K.

T indicates the Kelvin temperature, namely 290 K.

W indicates the signal bandwidth, namely 3.84 M.

When dBm is taken as the calculation unit:

Noise = 10lg(KT) + 10lg(W).

10lg(KT) indicates the thermal noise density (in the unit of dBm/Hz).

Nf indicates the BS noise coefficient, defined as the ratio of input S/N to output

S/N. 3GPP does not have specific requirement for the equipment noise. It is

generally taken as 3 dB for link budget.

IM indicates the noise increasing caused by system load.


18181818

S(dBm) = Eb/No(dB) + 10lg(KTW) + Nf(dBm) + IM(dBm) - 10lg(W/R).

The formula of BS receiving sensitivity is:

Receiver Sensitivity = 10lg(KT) + Nf + 10lg(Eb/No) + 10lgR + IM.

10lg(KT) indicates the thermal noise density, namely –174 dBm/Hz.

Nf indicates the BS noise coefficient, namely 3 dB.

IM indicates the interference margin.

8. Soft handoff gain

Here, soft handoff gain indicates the gain to overcome slow fading. When the

mobile equipment is located in the soft handoff region, multiple radio links of

soft handoff receive signals at the same time, which decreases the requirement

for the shadow fading margin. The soft handoff gain is generally taken as 3 dB

for link budget.

9. Power control margin (fast fading margin)

The WCDMA system adopts the fast closed-loop power control of 1500 Hz. For

a low-speed mobile terminal, the fast closed-loop power control of 1500 Hz can

fight fast fading and guarantee the demodulation performance. Because of the

features of fast fading, however, the fast power control cannot compensate deep

fading when the low-speed mobile terminal is in deep fading. In this case, the

UE (Node B) needs to fight deep fading by increasing the average transmitting

power. When the UE is located at the edge of a cell, the fast power control

cannot compensate deep fading either. Therefore, it is necessary to reserve a

certain dynamic adjustment scope of transmitting power for the fast closed-loop

power control during link budget. The power control margin is generally taken

as 3dB.

For a medium-speed or high-speed terminal (moving speed ≥ 50 km/hour), the

interleave in the channel code functions to fight fast fading while the fast

closed-loop power control has little function. So it is unnecessary to reserve the

power control margin.

10. Penetration loss

The penetration loss of buildings and vehicles is an important factor that

influences the radio coverage. The penetration loss is related to the specific


19191919

building/vehicle type and incident angle of radio wave. Suppose that the

penetration loss complies with lognormal distribution during link budget, and

use the average value of penetration loss and standard deviation to describe it. If

the radio coverage outside buildings is effective, it is enough to set the

penetration loss to 10dB–15dB. To receive and initiate calls at the core part of a

building, it is necessary to set the penetration loss to 30dB. Similarly, the

penetration loss is also important to the coverage inside vehicles. A car has the

penetration loss of 3dB to 6dB, and vans and buses may have larger changes.

The penetration loss at the front of vans should not exceed that of cars, but that

at the rear of vans may reach 10dB to 12dB. The specific value is dependent on

the number of windows. Therefore, it is necessary to set a reasonable penetration

loss value in accordance with actual conditions of the planning region during

link budget to guarantee good service quality.

11. Shadow fading margin

The shadow fading complies with lognormal distribution. Its value is related to

the sector edge communication probability and shadow fading standard

deviation, while the latter is related to the electromagnetic wave propagation

environment.

The fading margin is reserved to overcome fading changes and guarantee

reliability of communications in the cell. It shall correspond to certain

requirements of cell edge communication probability.

In the radio space propagation, the path loss of any a given distance changes

rapidly and the path loss value can be regarded as a random variable in

conformity with lognormal distribution. In the case of network design in

accordance with the average path loss, the loss value of points at the cell edge

shall be larger than the path loss median for 50% of time period, and smaller

than the median for the left 50% of time period. That is, the edge coverage

probability of the cell is 50% only. In this case, it is hard for subscribers at the

cell edge to obtain expected service quality with 50% of probability. To improve

coverage probability of the cell, it is necessary to reserve the fading margin

during link budget. The edge coverage probability is generally taken to 75% for

link budget. The following takes the edge coverage probability equal to or larger

than 75% as an example:


20202020

Suppose the random variable of propagation loss to ζ which is Gaussian

distribution on dB. Set the average value to m , the standard deviation to δ ,

and the corresponding probability distribution function to Q . Set a loss

threshold 1ζ . If the propagation loss is larger than this threshold, the signal

strength will fail to meet the demodulation requirement of expected service

qualities. The edge coverage probability equal to or larger than 75% can be

represented as:

∫∞−

−−=<=

1

2

)(

cov

2

2

2

1)1(

ζδ

ζ

ζδπ

ζζ dePPm

rerage

For the outdoor environment, the standard deviation of the random variable of

propagation loss is always taken to 8 dB. The margin value corresponding to the

edge coverage probability (communication probability) of 75% is:

dBm 4.58675.0675.01 =×==− δζ

See Fig. 2.2-1 and Fig. 2.2-2:

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

- 3 - 2. 5 - 2 - 1. 5 - 1 - 0. 5 0 0. 5 1 1. 5 2 2. 5 3

75%75%75%75%

0.6750.6750.6750.675

σσ σσ

Accumulated normal probability distribution

Median

Deviation with median signal m

Fig. 2.2-1 Fading Margin——Probability Distribution Function


21212121

m

Normal distributionprobability density function

Standard deviation=8dB 0.675 x8=5.4dB

Threshold Propagation loss

Fig. 2.2-2 Fading Margin——Probability Density Function

The above figures show that it is necessary to reserve 5.4 dB margin to guarantee the

edge coverage probability of 75% in the network planning. An easier method is to

calculate by using the NORMINV function in Excel. Table 2.2-5 and Fig. 2.2-3 show

the values of shadow fading margin and edge coverage probability in different standard

deviations.

Table 2.2-5 Shadow Fading Margin and Edge Coverage Probability in Different Standard

Deviations

Shadow Fading Margin Edge Coverage Probability δ = 6dB δ = 8dB δ = 10dB δ = 12dB

50% 0 0 0 0

55% 0.75 1.01 1.26 1.51

60% 1.52 2.03 2.53 3.04

65% 2.31 3.08 3.85 4.62

70% 3.15 4.20 5.24 6.29

75% 4.05 5.40 6.74 8.09

80% 5.05 6.73 8.42 10.10

85% 6.22 8.29 10.36 12.44

90% 7.69 10.25 12.82 15.38

95% 9.87 13.16 16.45 19.74

98% 12.32 16.43 20.54 24.64


22222222

00. 75

1. 522. 31

3. 154. 05

5. 05

6. 22

7. 69

9. 87

01. 01

2. 033. 08

4. 20

5. 40

6. 73

8. 29

10. 25

13. 16

0

1. 26

2. 53

3. 85

5. 24

6. 74

8. 42

10. 36

12. 82

16. 45

0

1. 51

3. 04

4. 62

6. 29

8. 09

10. 10

12. 44

15. 38

19. 74

0

2

4

6

8

10

12

14

16

18

20

22

50% 55% 60% 65% 70% 75% 80% 85% 90% 95%

σ＝6dBσ＝8dBσ＝10dBσ＝12dB

Sh

ado

w f

adin

g m

argi

n (

dB

)

Edge coverage probability

Fig. 2.2-3 Shadow Fading Margin and Edge Coverage Probability in Different Standard Deviations

2.2.2 Unlink Budget

The parameters taken in the last section can be used to calculate the uplink budget

under different environments and coverage requirements. The following table shows

the calculation process:

Table 2.2-6 Uplink Budget

Parameter Symbol

Maximum transmitting power of UE A

UE antenna transmitting gain B

UE transmitting loss (human body loss) C

Actual maximum transmitting power of UE per channel D= A +B – C

Environment thermal noise power spectrum density E

Uplink noise figure F

Uplink receiving noise power spectrum density G = E +F

Uplink noise rise H

Total BS uplink receiving interference power spectrum density I = G + H

Uplink signal quality requirement Eb/No J

Uplink service rate K


23232323

Parameter Symbol

Uplink receiving sensitivity L = I + 10lg(3.84*106) +(J

– 10lg (3.84*106/ k ))

BS antenna gain M

BS integrated loss N

Shadow fading margin P

Soft handoff gain Q

Power control margin R

Penetration loss S

Maximum loss T = D -L +M-N-P+Q-R-S

2.2.3 Uplink/Downlink Balance

Different from uplink budget, downlink budget makes all subscribers in the cell share

the BS power at the same time. The BS power distribution aims to make all subscriber

services connected with the BS in the cell match the corresponding service level.

Besides the number of subscribers in the cell, the downlink cell radius is also related to

the location and services of the subscriber.

The following table shows the parameters that cause the maximum allowed path loss

difference between uplink budget and downlink budget. The downlink is usually

limited by the capacity. When the load of the cell increases, the condition of limited

downlink may occur.

Table 2.2-7 Uplink/Downlink Parameter Comparison

Parameter Uplink Downlink

Receiver noise coefficient (dB) 2.2 7

Maximum transmitting power (dBm) 21 Depending on the maximum single-channel

transmitting power

Receiving-end Eb/No (dB) (12.2 kbps) 4. 2 7.2

The balance between the uplink and downlink needs the help of planning software for

iterative calculation. The calculation includes the uplink coverage estimation and the

downlink power distribution. It shows link balance if the total power does not exceed

the maximum BS transmitting power. If the total power required by the downlink

exceeds the maximum BS transmitting power, it is necessary to reduce the coverage

area and conduct the downlink power distribution again until the total power is smaller


24242424

than or equal to the maximum BS transmitting power.

2.3 Coverage Scale Estimation

2.3.1 Calculation of BS Coverage Radius

After acquisition of the maximum allowed path loss between MS and BS via link

budget, it is easy to estimate the BS coverage radius by combining with the local radio

propagation model. In fact, the radio propagation model describes the relationship

between path propagation loss and coverage distance. The maximum allowed path loss

and radio propagation model that have been known can be used to conversely deduct

the maximum BS coverage radius. If the coverage radius of macro-cell BS is to be

estimated only without considering the topographic features, the macro-cell radius can

be calculated by using the Cost231-hata model.

α10=R( ) ( )bmmb hAhChfPathloss lg55.69.44/lg82.13lg9.333.46 −+−+−−=α

Pathloss indicates the maximum allowed path loss, acquired via link budget.

f indicates the carrier frequency, in the unit of MHz.

bh indicates the BS antenna height, in the unit of m.

d indicates the distance from the MS to the antenna, in the unit of Km.

mAh indicates the mobile antenna height correction factor.

mC indicates the big-city center correction factor, 3 dBm for big cities and 0 dBm for

medium and small cities.

Tips:

In practice, the universal model of emulation software (such as Aircom) is generally

used:

Path loss = k1 + k2log(d) + k3Hms + k4log(Hms) + k5log(Heff) + k6log(Heff)log(d) +

k7(diffraction loss) + clutter loss

Obtain the radio propagation model that best matches the actual environment of the

local area by correcting k1, k2, k3, k4, k5, k6, k7(diffraction loss) and clutter loss.


25252525

2.3.2 Calculation of BS Coverage Area

The cell coverage radius “R” calculated in the last section can be used to obtain the BS

coverage area “Area” and inter-BS distance “D”. The BS coverage area is related to the

BS type. The following shows some common BS types of Node B:

1. Omni-directional BS

R D

Area = 232

3R , D = R3

2. Three-sector directional BS (65° horizontal lobe)

D

R

Area = 238

9R , D = R

2

3

3. Six-sector directional BS


26262626

DR

Area = 232

3R , D = R3

2.3.3 Scale Calculation

The planning region area divided by the single-BS coverage area is the number of BSs

that can cover the region with coverage requirements satisfied.

27272727

3 WCDMA Capacity Estimation

3.1 Capacity Estimation Flow

The capacity estimation is another important part of the scale estimation. The purpose

of capacity estimation is to estimate the approximate BS number needed by the

capacity according to the service model and service traffic demand of the network

planning. Similar with the link budget, the capacity estimation should be performed

from the uplink and downlink. For the WCDMA system capacity, the interference is

limited in the uplink direction and the BS power is limited in the downlink direction. In

the 2G CDMA network, the voice service is the main application service with

symmetrical uplink and downlink traffic, the capacity is limited in the uplink direction,

so the uplink capacity calculation is focused on in capacity estimation. However, in the

WCDMA network, the data service proportion is obviously increased and the network

uplink and downlink traffic becomes asymmetric generally, and even the downlink

capacity may be limited. Therefore, the WCDMA capacity estimation should be

performed from the uplink and downlink respectively. The following steps are involved

in capacity estimation:

1. Hybrid service intensity analysis. The WCDMA system can provide multiple

services. The hybrid service intensity analysis makes the system capacity

consumed by various services equivalent to that consumed by a single service.

2. Uplink capacity estimation. Estimate the BS number that meets the service

demand based on the hybrid service intensity analysis.

3. Downlink capacity estimation. It is a verification process. The BS transmission

power formula is used to calculate the channel number that can be provided by

the current BS scale so as to verify whether this channel number can meet the

capacity requirement, and if it cannot, stations need be added.

3.2 Estimation Method of Hybrid Service Capacity

There are multiple services in the WCDMA network, their service rates and required

Eb/No are diversified, the effects on the system load and consumed BS resources are

different, so the estimation for the cell capacity cannot adopt the method for estimating


28282828

the cell capacity in a pure voice network. An idea of hybrid service capacity estimation

is to make equivalent among various services to make the system capacity consumed

by various services equivalent to that consumed by a single service. The Equivalent

Erlang, Post Erlang-B and Campbell methods in the hybrid service estimation are

introduced respectively as follows.

3.2.1 Equivalent Erlang Method

The fundamental principle of the Equivalent Erlang method is to make a service

equivalent to another service, calculate the total traffic (erl) of the equivalent services

and count the channel number needed by this traffic. We will give an example to

explain it as below.

Suppose services A and B are provided in the network, where,

service A: each connection occupies one channel and the total is 12 erl;

service B: each connection occupies 3 channels and the total is 6 erl.

If 1 erl service B is equivalent to 3 erl service A, the total traffic in the network will be

12+6*3=30 erl (service A). After querying Table erl-B, we know that altogether 39

channels are needed under 2% blocking rate.

If 3 erl service A is equivalent to 1 erl service B, the total traffic in the network will be

12/3+6=10 erl (service B). After querying Table erl-B, we know that altogether 17

service B channels (equivalent to 17*3=51 service A channels) are needed under 2%

blocking rate.

Upon the above analysis, we know that calculation result through the Equivalent

Erlang method is related to the equivalent mode adopted. The result through the former

equivalent mode is too small (39 channels) which is too optimistic, while the result

through the latter mode is too large (51 channels), which is too pessimistic, as shown in

the following figure:


29292929

Capacities meeting thesame GOS are different

Low speedservice

equivalent

2 Erl Lowspeed service

1 Erl Highspeed service

High speed serviceequivalent The calculation

result is relatedto the

equivalentmode

3.2.2 Post Erlang-B Method

The fundamental principle of the Post Erlang-B method is to calculate the channel

number required by each service capacity respectively and add channels in an

equivalent manner to obtain the channel number required by the hybrid service capacity.

We will give an example to explain it as below.




After querying Table erl-B, we know that altogether 19 channels are needed to meet

service A traffic (12 erl) under 2% blocking rate.

After querying Table erl-B, we know that altogether 12 service B channels (equivalent

to 12*3=36 service A channels) are needed to meet service B traffic (6 erl) under 2%

blocking rate.

The two services need 19+36=55 channels totally.

Calculate the network capacity in a special case based on the Post Erlang-B method:

Suppose services A and B are the same kind, where,



After querying Table erl-B, we know that altogether 19 channels are needed to meet


30303030

service A traffic (12 erl) under 2% blocking rate.

After querying Table erl-B, we know that altogether 12 channels are needed to meet the

service B traffic (6 erl) under 2% blocking rate.

Services A and B need 19+12=31 channels totally.

Because services A and B are the same kind, the total traffic is 12+6=18 erl. According

to the currently known method of capacity calculation in single service, after querying

Table erl-B, we know that 26 channels are needed to meet the traffic demand under 2%

blocking rate. This result is correct obviously.

Upon above analysis, we can see that the calculation result through the Post Erlang

method is too pessimistic (31>26). The reason is that the BS channels are shared

among services, however, the Post Erlang method factitiously separates the channels

used by the services, and thus, the BS channel resource utilization ratio is reduced, as

shown in the following figure:

Capacities meeting the sameGOS are different

1 ERL service A

1 ERL service B

1 ERL service A and1 ERL service B

Thecalculationresult is toopessimistic

3.2.3 Campbell Method

The fundamental principle of the Campbell method is to make all services equivalent to

a virtual service based on certain rules, calculate the total traffic (erl) of this virtual

service, count the virtual channel number needed by this traffic, and convert the

number into the actual channel number that meets the network capacity.

The equivalent principle of the Campbell model:


31313131

∑

∑==

iii

iii

aerl

aerlv

c

2

α

cfficOfferedTra

α=

c

aCCapacity ii )( −

=

Where, c indicates capacity factor.

v indicates hybrid service variance.

α indicates hybrid service mean.

ia indicates the equivalent intensity of service i.

iC indicates the channel number needed by service i.

OfferedTraffic indicates traffic of the virtual service.

Capacity indicates the virtual channel number needed by the virtual traffic.

We will give an example to explain it as below.




Equivalent intensity of service A a1=1 and that of service B a2=3.

The hybrid service mean is ∑ =×+×==

iii aerl 3036112α

The hybrid service variance is ∑ =×+×==

iii aerlv 6636112 22

The capacity factor is 2.2

30

66 ===αv

c

The virtual traffic is 63.13

2.2

30 ===c

fficOfferedTraα

After querying Table erl-B, we know that altogether 21 virtual channels are needed to


32323232

meet the virtual traffic under 2% blocking rate.

According to formula (), under 2% blocking rate, the channel number needed by each

service is shown as follows:

Service A: 471)2.221(1 =+×=C

Service B: 493)2.221(1 =+×=C

From the above analysis, compared with results of the Equivalent Erlang and Post

Erlang-B methods, the result of the Campbell method is more credible, so it is a more

reasonable estimation method for hybrid service capacity at present. According to the

Campbell method, under the same requirement of the service level GOS, diversified

channel resources are needed by different services, or, under the same channel

resources, different services obtain diversified service levels. From this point of view,

the Campbell method is more reasonable. However, the Campbell method makes all

services uniformly equivalent as the circuit domain services and uses the Erlang-B

model for analysis and calculation. In fact, the features of the packet domain services

are completely different from those of the circuit domain services, and in addition, the

Erlang-B establishment conditions are not satisfied, so this equivalent method has

defects itself. A further research is needed for better hybrid service establishment

model and capacity analysis method.

In the Campbell method, the service equivalent intensity a can be calculated based on

channel number consumed by each kind of service or based on the interference

introduced from the air interface by each kind of service, shown as follows:

1 amplitudefor 1 amplitudefor ratebit

servicefor servicefor ratebit amplitude Relative

0

0

NE

NE

b

b

×

×=

If the reference service is the voice service, with its activity at the physical layer

considered, the above formula can be modified to:

for voice vfor voicefor voice ratebit

servicefor servicefor ratebit amplitude Relative

0

0

××

×=

NE

NE

b

b


33333333

3.3 Uplink Capacity Estimation

3.3.1 Load Analysis for Uplink

In the WCDMA system, all users adopt the same carrier and each signal becomes a

noise (interference) for others upon coding. Therefore, each signal is contained in the

bandwidth interference background generated by other user. To access a call, the

mobile station power must be large enough to overcome other mobile stations in the

bandwidth, that is, the receive signal in the BS must reach Eb/No (energy per user bit

to noise spectral density) required by the service demodulation.

NoEb j ×=)/( User J's handling gainUser J's signal

Total receive power (without its own signal)

The above formula can be written into:

jtotal

j

jjj PI

P

Rv

WNoEb

−⋅=)/(

Where, W indicates the chip rate, 3.84 Mchip/s.

vj indicates user j’s activation factor.

Rj is user j’s bit rate.

Pj indicates receive power for signals from user j.

Itotal indicates total broadband receive power with the thermal noise power included of

the BS.

From the above formula, we know that the receive power at the BS receive end should

meet the following formula so that the user signal can meet the demodulation

requirement:

total

jjj

j I

vRNoEb

WP

)/(1

1

+=


34343434

Define a connection load factor Lj:

jjj

j

vRNoEb

WL

)/(1

1

+=

Lj indicates the ratio of user signal power to the total BS receive power, so a single

user signal power Pj is represented to tataljj ILP =.

The total receive power of all N users from one cell is:

∑∑==

=N

jtatalj

N

jj ILP

11

Generally, the total receive power at the BS receive end consists of in-cell user

interference power, out-cell user interference power and BS thermal noise, that is:

Notherintatal PPPI ++=

Where, Pin indicates the total interference power of in-cell users.

Pother indicates the total interference power of out-cell users.

PN indicates the BS thermal noise power.

Because the out-cell mobile station interference power is not controlled by the local

cell BS, the interference is hard to determine. Generally, define the ratio of the

interference from other cell to that of the local cell as the neighbor cell’s interference

factor i:

=iOther cell interference

Local cell interference

i indicates the ratio of other cell interference to the local cell interference at the BS

receive end of the local cell. Generally, the neighbor cell interference factor of the

macro cell that adopts omni antenna is 0.55 and that of the macro cell that adopts

three-sector antenna is 0.65.


35353535

Therefore, the total user receive power of the BS is:

∑=

+=+N

jtataljotherin ILiPP

1

)1(

Define the noise lifting as the ratio of total broadband receive power to the noise power

of the BS, that is:

∑=

+−

=−−

==N

jj

otherintatal

tatal

N

total

LiPPI

I

P

INR

1

)1(1

1

Define the uplink load factor ULη as

∑∑== +

+=+=N

j

jjj

N

jjUL

vRNoEb

WiLi

11)/(

1

1)1()1(η

ULη indicates the ratio of the user signal power at the BS receive end to the total

receive power of the broadband.

Then, the noise lifting can be represented to:

UL

NRη−

=1

1

or )1(10)( 10 ULLOGdBNR η−−=

This equation reflects the thermal noise lifting caused by user interference at the BS

receive end. 3 dB noise lifting corresponds to 50% load factors and 6 dB noise lifting

corresponds to 75% load factors. Generally, the network planning supposes that the

uplink load factor is 50%, in a single service, the channel number provided by each cell

can be calculated through formula (1), and then, the total BS number required by the

uplink capacity demand can be counted further. For the capacity estimation for hybrid

service, the Campbell algorithm should be combined to make the system resources

consumed by various services equivalent to those consumed by a single service. Then,

the channel number provided by each cell can be calculated through formula (1), and

the BS number required by the hybrid service capacity demand can be counted further.

The next section details the capacity estimation flow of the hybrid service.


36363636

Tips:

The uplink noise lifting NR corresponds to the interference margin in the uplink

budget, that is, the coverage is related to the capacity. In planning, the network load

factor should be determined to get the noise lifting corresponding to this load. Then,

the BS radius meeting the uplink capacity requirement can be calculated further

through the link budget.

3.3.2 Uplink Capacity and Scale Estimation

The previous section describes the load factor of uplink, based on which, this section

describes how to estimate the BS quantity satisfying the composite traffic requirements

for uplink. Fig. 3.3-1 shows the flow of estimating uplink capacity.

Calculate equivalent

intensity of services

Calculate the variance,

average value and capacity

factor of the mixed service

Virtual traffic A of the

system

Calculate the quantity

of equivalent voice channels

in a cell

The quantity of virtual

channels in the sell

Virtual traffic B of the cell

Numberof cells

A/B

Fig. 3.3-1 Flow Chart of Estimating Uplink Capacity

1. Calculate the virtual composite traffic of the system.

Because various services have different effects on system load, such an effect


37373737

can be equivalent to the effect of multiple voice channels on system load. The

calculation formula is as follows:

amplitude service= (Rservice x Eb/Noservice x vservice)/ (Rvoice x Eb/Novoice

x voice)

Where, R represents service rate.

Eb/No represents quality factor of the service.

v represents the activation factor of the service at the physical layer

According to the Campell theory, the virtual composite traffic of the system can

be calculated.

2. Calculate the quantity N of equivalent voice channels provided by a cell.

Suppose that system capacity load is represented by η , the uplink capacity

formula is as follows

∑+

+=N

j

o

bj

N

EvR

Wf

1*

1*1

1*)1(η

Where, η represents load factor, f represents interference factor from an adjacent

cell, v represents activation factor and N represents the quantity of channels.

According to the above formula, the quantity N of equivalent voice channels

provided by a cell can be evaluated.

3. Calculate the quantity of virtual channels in every cell

Bases on the quantity N of equivalent voice channels evaluated in step 2 and the

following formula

voice channel=virtual channel*C

Where, voice channel is the quantity N of equivalent voice channels

The quantity of virtual channels in every cell can be evaluated.

4. Look up Table Erl B according to the quantity of virtual channels evaluated in

step 3, and get the quantity of virtual traffic in every cell.

5. Calculate the quantity of cells


38383838

According to the virtual composite traffic of the system evaluated in step 2 and

virtual traffic of every cell evaluated in step 4, calculate the quantity of required

cells:

the number of cells=composite traffic/the virtual Erlang number every cell

The quantity of BSs required in three sectors is calculated as follows: the

number of cells/3.

3.4 Downlink Capacity Estimation

3.4.1 Analysis of Downlink Load

On the downlink, BS power is shared by all users in a cell. When no power in total BS

power can be allocated to a new user, air interface capacity reaches its limit. That is to

say, when a BS transmits the total power used for normal running of all users exceeds

the rated power of the BS, downlink capacity reaches power limit. Therefore, downlink

capacity is limited by the total transmitting power of the BS.

Similar to the analysis method of uplink capacity, analysis of downlink capacity starts

from the Eb/No value required by signal demodulation. To correctly demodulate useful

signals on the downlink, the mobile station must overcome interference from the

following three aspects: interference caused by nonorthogonality of the channel in a

cell, interference of signals from the outside of the cell and thermal noise from the

mobile station. That is,

Nothertatal PPPI ++−= )1( α

Where, P represents total BS transmitting power.

Pother represents total interference power of signals from the outside of the cell.

PN represents thermal noise power from the mobile station.

α represents quadrature factor of the downlink.

On the downlink, quadrature factor α is a very important parameter. Users on the

downlink of WCDMA are differentiated based on the orthogonal code. In the case there

is no multipath propagation, orthogonality keeps unchanged when the mobile station

receives signals from the BS. However, in the actual process of signal propagation,

multipath delay is unavoidable, therefore orthogonality between channels is damaged,


39393939

thus causing interference. Quadrature factor 1 corresponds to the user fully orthogonal.

Generally, quadrature factor in the multipath channel is between 0.4 and 0.9.

By referring to the derivation means of uplink load factor, denote the downlink load

factor DLη as follows:

∑=

+−=N

jjj

j

jjDL i

RW

NoEbv

1

])1[(/

)/(αη

Where, W represents chip rate at 3.84 Mchip/s.

vj represents activation factor of the user j.

jR represents bit rate of the user j.

jα represents channel quadrature factor from the user j.

ji represents the ratio of BS power received by the user j from other cell to that from

this cell.

Because mobile stations are distributed randomly in a cell, jα and ji are related to

the location of users. For the average value of cell load factors, adopt its similar

average value in the whole cell, that is:

∑=

+−=N

j j

jjDL i

RW

NoEbv

1

])1[(/

)/(αη

Where, α represents the average quadrature factor in a cell. Generally, it is 60% for

the multipath channel and 90% for the non-multipath channel. i represents the

average ratio of the BS power received by the user from other cell to that from this cell.

Generally, it is 55% for the omni antenna macro cell and 65% for the three-sector

antenna macro cell.

During the analysis of downlink capacity, estimation of BS transmitting power is the

most important. The estimated BS transmitting power is average power not peak power

at the cell boundary, because the transmitting power distributed by the BS for each user

is determined by the average loss from the BS to the mobile station and the sensitivity

of the mobile station. On the actual network, users are distributed randomly in a cell,

not at the cell boundary, therefore, the average path loss value, not the maximum path


40404040

loss value estimated for the link, should be adopted when BS transmitting power is

calculated. In a macro cell, the difference between the maximum path loss and the

average path loss is usually 6 dB.

The total BS transmitting power can be expressed by the following formula:

DL

N

j j

jjrf RW

NoEbvLWN

TxPBSη−

=∑

=

1

/

)/(

_1

Where, rfN represents the noise power spectrum density on the front of the mobile

station receiver, and it can be calculated by the following formula:

)290(sup0.174 KposeTNFdBmNFKTNrf =+−=+= Where, NF

represents the noise coefficient of the mobile station receiver with the typical value of 5

dB to 9 dB.

L represents the average path loss, which is evaluated by subtracting 6 dBm from the

maximum path loss.

vj represents activation factor of the user j.

Rj represents bit rate of the user j.

In the case of a single service, evaluate the channel quantity provided by every cell

under the maximum allowed transmitting power according to the formula (2) and

further evaluate the total number of BSs satisfying downlink capacity requirements.

In fact, the analysis of uplink and downlink link performances is a hard process.

Because the performance of downlink depends on many basic elements very much, its

analysis cannot be streamlined like the analysis of uplink. The Eb/No value range of

downlink is a parameter changing greatly with moving speed and multipath condition.

In addition, the mobile station receiver does not use antenna diversity. The reason why

the required Eb/No value changes with the mobile station is that at least two paths

cannot be ensured unless it is clearly known that the mobile station is in soft handoff or

softer handoff statuses. Such a change, randomicity of mobile station location and

interference level from the surrounding cell make the analysis of downlink

performance complicated. In designing, a very conservative conclusion can be gotten

in the case the worst condition is considered. Generally, estimate capacity after

analyzing the channel quantity required by uplink capacity, and observe whether the


41414141

downlink can support the mobile station to work in the designated coverage area and

its channel quantity reaches the channel quantity generated by the uplink.

3.4.2 Downlink Capacity and Scale Estimation

Downlink estimation is a verification process. The process of downlink capacity and

scale estimation is as follows: First calculate the quantity of equivalent voice channels

to be provided by this cell in the current service model, and then calculate the quantity

of equivalent voice channels availably provided by the cell according to the downlink

power calculation formula, and subsequently compare these two results. If the quantity

to be provided by the cell is less than that availably provided by the cell, it indicates

that downlink power is enough and the current scale satisfies system capacity

requirements. If the former is larger than the latter, it indicates that downlink capacity

is limited. To make downlink power enough, add some BSs.

1 Calculate the quantity of equivalent voice channels to be provided by every cell.

Under the precondition of known reverse capacity and scale, you can evaluate

the traffic of various services in every cell under such a scale. Then, according to

the equivalence of voice channels, you can evaluate the quantity of equivalent

voice channels to be provided by every cell. This quantity can be calculated by

following several steps below

1) Calculate the average traffic of various services in every cell according to the BS

quantity of uplink and total traffic of downlink.

Average traffic of various services in a cell = 3×ntityStationQuaUplinkBase

inkTrafficTotalDownl

Where, the BS quantity is the larger value between estimated uplink coverage

and estimated capacity result.

2) According to the Campell theory, calculate the virtual Erlang traffic in every cell.

The calculation method in this step is the same as that of uplink.

3) Look up Table Erl B according to the virtual Erlang traffic in every cell

evaluated in step 2, and calculate the quantity of virtual channels in every cell.

4) According to the quantity of virtual channels evaluated in step 3 and the

following formula


42424242

c

aCCapacity ii )( −

=

you can evaluate the quantity of equivalent voice channels to be provided by

every cell.

2. Calculate the quantity of equivalent voice channels availably provided by the

cell.

According to the forward power formula

])1[(/

)/(*1

/

)/(***

1

1

jj

N

j j

jj

N

j j

jjN

RW

NoEbv

RW

NoEbvLP

P

αλ +−−=

∑

∑

=

=

Where, PN represents the noise power spectrum density on the front of the

mobile station receiver, and it can be calculated by the following formula:

)290(sup0.174 KposeTNFdBmNFKTPN =+−=+= ,

NF represents the noise coefficient of the mobile station receiver with the typical

value of 5 dB to 9 dB.

L represents the average path loss, which is evaluated by subtracting 6 dBm

from the maximum path loss. jλ represents the average quadrature factor.

Generally, it is 0.6 for the multipath channel and 0.9 for the non-multipath

channel.

jα represents interference factor from an adjacent cell. Generally, it is 0.55 for

the omni antenna macro cell and 0.65 for the three-sector antenna macro cell.

The quantity of equivalent voice channels availably provided by the cell can be

calculated.

3. Compare the above two results. If the quantity to be provided by the cell is less

than that availably provided by the cell, it indicates that downlink power is

enough and the current scale satisfies system capacity requirements. If the

former is larger than the latter, it indicates that downlink capacity is limited. To

make downlink power enough, add some BSs.

43

4 Survey of Network Planning

4.1 Overview

The site survey of the WCDMA radio network planning is an important part of the

network planning work, which must be done carefully. The surveyor of network

planning site should carefully make the planning survey for sites and ensure the

authenticity and correctness of survey data. Make a good preparation for the incoming

network construction and provide an effective planning report for the later network

optimization.

The site survey and selection are conducted by the engineers of the operator and the

network planning engineers together. The network planning engineers put forward the

suggestion of site selection. The network planning engineers should be familiar with

the radio propagation environment and traffic density distribution around each site

through investigation and site selection, to obtain the latitude and longitude

information of the site.

4.2 Selection of Base Site

4.2.1 Method of Selecting Site

Site selection is crucial in the entire network planning process. If the site is selected

properly, it is only necessary to make a fine tune for the parameters in the planning.

Contrarily, if the site is selected improperly, it will lead to poor planning performance,

and even reselecting the site. In this case, the planning work in the former stage is

useless.

First, try to select the ideal location specified by the cell in the wireless communication

theory. The offset should be restricted about one quarter of base coverage radius R for

the cell splitting and network development in future. This is a basic principle of

network planning. The purpose is to identify the overall frame of he network.

The sites can be selected in the following ways:


44444444

4.2.1.1 Selection by Coverage and Capacity Requirem ents

Meeting the coverage and capacity is the most direct object of setting a site. Try to

meet the two conditions when selecting a site. In important areas, the capacity

requirement is high. Many base stations are required and the service demands are

urgent. So, these areas should be considered first during the site selection. In the areas

with a low requirement for capacity, site selection emphasizes particularly on the

coverage.

According to the above factors, select sites according to the following rule:

1. It is necessary to select sites for important coverage areas.

2. It is necessary to select sites for the main trunk road in the central urban area.

3. After selecting the critical sites, implement the large-area continuous coverage

for minor coverage area.

In the WCDMA radio network planning, the planning of the important coverage area is

pretty important. Setting the base stations in the important coverage area ensures

providing a good power coverage for mobile stations in these areas and meanwhile

absorb the traffic around effectively, thus improving the utility of the system. If the site

is selected properly, it can reduce the transmission power level of UE and thus reduces

the interference and increases the network capacity.

Point coverage: It indicates the coverage over important areas, including important

functional areas like office area of (provincial) municipal government, office area

(building) of operators, office building, star-level hotel, luxurious house area,

large-scaled shop, entertainment places and transport junction. There must be sites on

the building of the important coverage area or surrounding the important coverage area

within 50 m by taking the important coverage area as center. The distance between

base stations in the important coverage area is between 500 m and 800 m.

Line coverage: It indicates the coverage over the main business street, main transport

street in the city, inter-city freeway and airport road. Ensure that the traffic can shift on

the lines. Only after the line coverage is ensured, can the basic satisfaction of important

point users be ensured.

Plane coverage: After the above primary sites are selected, make the coverage on the

area plane with service demands. The purpose is to connect the independent important

areas and ensure the continuous coverage and seamless coverage of network.


45454545

4.2.1.2 Selection by Base Station Surroundings

After identifying the area for setting up base station, according to the effect factor of

surroundings (like height above sea level and types of surface features) on the radio

transmission, select a proper point which make the radio wave achieve a good coverage

in the area.

According to the above factor, the requirements for the sites are:

1. The sites should be located in the place high enough.

2. However, the place where he sites are cannot be too high.

3. The height different between two adjacent sites cannot be too large

The geographical environment such as plain, hill, a mountainous area, lake and island

cannot be changed. Therefore, screen the sites (buildings or surface features) in the

planning area to get the sites suitable for the geographical and surface features

environments in the planning area.

The location of the site should be high enough. The height of antenna of base stations

directly affects the coverage range of the cell. The antenna height should be higher than

the average height of buildings in the coverage area. Only in this case, the signal

density in the coverage area can be ensured. You can understand the importance of the

antenna height according to the radio wave propagation mechanism. According to the

current building density and average height, 35 m-height is a proper antenna height in

the urban area. In the rural area, 50 m –height is proper.

The site cannot be located too high and the height difference between the adjacent sites

cannot be too large, determined by the features of the WCDMA system. The WCDMA

is the interference-restricted system. Overheight site usually crosses several coverage

areas. Thus, it will interfere with other cells and in result limits the capacity of the

entire system and reduce the general performance of the system.

4.2.1.3 Selection by Wireless Surroundings of Base Station

Avoid setting sites near the strong interferers like large-power radio station, radar

station and satellite ground station. The interference exists between the WCDMA

system and large-power transmitter. The transmission power of large-power transmitter

like microwave and medium wave is too large. As the out-of-band interference of the

base station, it can lead to the saturation effect of radio components, which may reduce

the sensitivity and coverage radius of the WCDMA base station.


46464646

At present, operator will take the wireless resources of existing network into account

fully when building a new network. Therefore, co-site with other wireless system is a

common choice. The currently-running radio network systems include GSM1800MHz,

GSM900MHz, CDMA1900MHz, CDMA800MHz and PHS network. In the co-site

situation, different systems will interfere with each other. The interference falls into by

generation mechanism: additive noise interference, crossmodulation interference,

blocking interference and intermodulation interference. The interference between

different systems can be resolved through the space isolation and adding filter. Usually,

the vertical/horizontal isolation between antennas is adopted to resolve the co-site

intersystem interference problem according to the roof of the base station.

Avoid setting site near the departments involved with the national security.

4.2.1.4 Selection by Existing Resources of Base Sta tion

The network planning is a comprehensive system project. It is necessary to master

various kinds of information and define a reasonable planning scheme according to the

technical indices of WCDMA products before implementing the project.

When making a new WCDMA network planning, we should take the existing mobile

network as the reference model of the WCDMA radio network planning for full

reference to improve the correctness of wireless planning greatly. For a inheritance

WCDMA radio network planning, it is necessary to make a complete test and analysis

for the existing network. On this basis, provide the WCDMA radio network planning

scheme.

For a new WCDMA network planning, take the existing mobile network information

into account fully and make the best use of the resources like transmission and power

supply.

Select a the area with convenient transportation for the site of base station for the

convenience of engineering and maintenance in future.

Finally, according to the above information, find the key points, define the survey plan

and scale reasonably and identify the number of valid sites. The core is the relationship

between investment and return. The object of radio network solution is to shorten the

investment return period and lower the operation cost and investment risks. The

coverage objects are summarized as point coverage, line coverage and plane coverage.

Through the point coverage, line coverage and plane coverage, absorb the traffic fully,


47474747

to make most subscribers satisfied.

4.2.2 Policy of Selecting Site

On the basis of site selection method mentioned in the former section, this section

gives some polices in the selection further:

1. The density of base station layout should correspond to the traffic distribution

conditions. If a few sites are to be established at the initial stage of network

construction, they should be selected appropriately to guarantee coverage for

important subscribers and highly-populated areas.

2. During the base survey in the urban area, the height of base station should

higher than the average height of buildings but lower than the height of the top

building. For base stations in the micro cells, the height of base station should be

lower than the average height of buildings and the shield of the buildings around

should be good. When surveying base stations in suburban or rural areas, it is

necessary verify if there are large-traffic areas that are likely to be obstructed

around the site.

3. When selecting sites in building groups of the urban area, try to avoid the

situation where the existing tall buildings or new buildings near the antenna

obstruct the area to be covered. Around the selected building is no obvious

barrier. There should be no building blocking the planned sector’s pointing to

the main lobe direction.

4. The antenna height should be higher than the average height of surroundings, 10

– 15 m higher than that in urban area with dense buildings and 15 m higher than

that in suburban and rural areas. The height of building or drawing tower should

meet the requirement of planned antenna height, which cannot 1.3 time higher

than the antenna height.

5. To establish base stations in urban areas, mains supply and lightning protection

grounding systems must be available inside the buildings and the floors must

have sufficient capacity to bear weights with adequate space on the building top

for antenna installation. To establish base stations in suburbs or the countryside,

sufficient infrastructures must be available: reliable mains supply, safe

environment, convenient transportation and facilities for iron tower

establishment.


48484848

6. Select the equipment room with low rentals and low reconstruction cost.

7. On condition that the base station layout is not affected, select the existing

telecommunication buildings, postal office buildings or microwave stations as

sites as much as possible, and make use of their equipment rooms, power

supplies and iron towers to the greatest extent.

8. When adopting the microwave transmission in the selected site, fully consider

the feasibility, cost and transmission performance of other transmission modes.

9. Try not to adopt rural power for direct power supply in the selected site, which

may affect the normal operation of base station due to unstable voltage.

10. The base stations in urban areas should be placed in one site or in two adjacent

sites as much as possible.

AT present, the operators may have their own overall planning of site selection, and

some sites may have their definite addresses. Our planning & survey engineers can tell

if the site selected by the customer is appropriate according to the above principles. It

not appropriate, they will continue the survey until a better one is found and then they

will propose their suggestions together with reasons to the customer for a final decision

(to confirm it in written form).

4.2.3 Mitigation in Site Selection

During the site selection, it should be specially noted to avoid the following cases:

When planning the WCDMA network, avoid the ring layout of base stations.

Fig. 4.2-1 Ring Layout of Base Stations


49494949

The purpose is to avoid the hole effect caused by the ring layout. In the ring

layout, the pilot intensity in the hole is not efficient and the surrounding base

stations can affect the hole, and in result the strong pilot pollution is generated.

It will not only impair the coverage in the hole but also impair the capacity of

surrounding base stations. Therefore, lay out base stations following the cell

structure.

1. There should be no barrier around.

Fig. 4.2-2 Barrier of Buildings Around

The barrier of building around has a large effect on the coverage of base stations.

There will be a shadow on the back of the barrier, causing the dead zone of

coverage. The reflection signal from the front of the barrier will bring

interference for the system. Usually, there should be no building 100 m around

the site which is 5 m higher than the site and no broad large building 200 m

around. However, this problem often occurs in the urban area with dense

buildings, which increases the difficulty of site selection in the city.

2. When planning the WCDMA network, avoid the case that the large-traffic object

is remote from the base station.


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Fig. 4.2-3 Large-Traffic Area Remote from the Base Station

When most subscribers are far from the base station, namely, most subscribers

are on the border of cell, the radio wave on the link will increase and the base

station and user equipment have to increase the transmission power accordingly.

In result, the interference of system increases, the power of base station to every

downlink subscriber increases and both uplink and downlink capacities

decrease.

3. When planning the WCDMA network, avoid the case of the base station

covering base stations.

Coverage area of base station

R1

Basestation

Adjacentbase station

R2

Fig. 4.2-4 Base Station Covering Base Station

Base station covering base station is mainly caused by large height difference

between two adjacent base stations. In this case, the two base stations will

generate pretty large interference, make the user equipment hand off frequently

and in result make the capacities of the two base stations decrease together. To

avoid this case, the antenna height of the base stations should be on the same


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level.

4. Do not set up base stations in woods. If that is a must, keep their antennas above

the top of trees.

5. Do not set up base stations near the large-power radio transmitter, radar stations

or other strong interference sources. If the above is inevitable, conduct the field

strength interference test first.

Do not set up base stations in high mountains. The base station at a high location

in the urban area has a large interference range. The base station at a high

location in the suburban or rural areas will cause poor coverage for the basin

countryside.

6. Do not set base stations in the border at a high location or too many base stations

in the border to avoid unnecessary dissension.

4.3 Collection of WCDMA Networking Planning Data

4.3.1 Overview

The collection of network planning data is the basis of planning and simulation. The

collection of planning-required data and analysis is closely related to the accurateness

of the network planning result. The subscriber number prediction, traffic model

prediction and user distribution are crucial to the planning. To predict the reasonable

data, the data collected must be rich and accurate. The network planning data mainly

come from the operators.

4.3.2 Project Information

Resources of operators:

1. Whether they have radio resources like equipment room, transmission

equipment and iron tower

2. Whether they have the three-dimension map. The format of electronic map used

is Planet/EET. This format supports the globe models including Krasovsky1940

and WGS84 and projection modes including GaussKruger and UTM.

3. Whether they have the information of existing radio mobile network of the

operator like traffic statistics, site distribution and site information. If yes,


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provide them otherwise.

4. Whether they have ZTE equipment. If yes, provide the type and running

situation of equipment.

4.3.3 Categorization of Coverage Area

First categorize the coverage area of the planning area by the traffic and surface

features of the coverage area.

The traffic categorization should consider the area size, population, social economy,

fixed call incomes and the distribution of mobile subscribers of competitors. Predict the

penetrability and traffic of services in an area.

Table 4.3-1 Categorized Statistics of Traffic

Service

Type

Bearer

Rate

(UL/DL)

Kbps

Penetrability

Outdoor

Coverage

Rate

Outdoor

Slow

Fading

Standard

Deviation

Indoor

Coverage

Rate

Indoor

Slow

Fading

Standard

Deviation

(dB)

Average

Subscriber

on Busy

Hour (erl)

Blocking

Rate

Average

Subscriber

Throughput

on Busy

Hour

(UL/DL)

bps

Voice

Service

cs12.2/cs

12.2

VIDEO

PHONE

cs64/cs6

4

Low

Data

Service

ps64/ps6

4

Medium

Data

Service

ps64/ps1

28

High

Data

Service

Ps64/ps3

84

Category of surface features: According to the economy of the planning area, it can be

categorized into dense urban area, common urban area, suburb and countryside. It is

necessary to learn the area range, area and subscriber distribution of each section of the

planning area.


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Table 4.3-2 Categorized Statistics of Surface Features

Type of

Surface

Features

Coverage Coverage Area

Number of

Covered

Subscribers

Dense Urban

Area

Use the street name to identify the closed coverage

area range. Take the northwest level crossing of the

northest street as the start point of the close loop,

named with the street name and called border. Form a

close area from north, east, south, west to north.

Area = Length (west to east) ×

Width (north to south)

Common

urban area

Use the street name to identify the closed coverage

area range. Take the northwest level crossing of the

northest street as the start point of the close loop,

named with the street name and called border. Form a

close area from north, east, south, west to north.



Suburb Describe the border of suburb and urban area and take

the street as the boundary.



Countryside Describe the landform of the countryside clearly only

(land features and surface features)



Note: The coverage range should be marked on the map.

4.3.4 Collection of Existing Resources

If the operators have radio resources which can be used by the WCDMA base stations,

like equipment room, iron tower, power and transmission equipment, it is necessary to

collect the data, as listed in Table 4.3-3.

Table 4.3-3 Statistics of Existing Radio Resources

S

N

Located

Region

Location

Name Longitude Latitude Address

Floors of

Equipment

Room

Iron

Tower

Power

Resources

Transmission

Resources


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4.3.5 Information of Important Transportation Line

Table 4.3-4 Information of Important Transportation Line

SN Name of

Transportation Line Glass of Road

Length of Important

Transportation Line

Important Areas Passed Through by

the Transportation Line

Note: The transportation line should be marked on the map.

4.3.6 Information of Important Buildings in Urban A reas

Table 4.3-5 Information of Important Buildings in Urban Areas

SN Name of Buildings Longitude Latitude Floor Function Type Structure of Building

Note: The location of important buildings should be marked on the map.

4.3.7 Information of Sites on the Existing Network

Table 4.3-6 Information of Sites on the Existing Network

Base

No.

Base

Name Longitude Latitude

CS

Type Altitude

Roof

Height

Antenna

Height

Type of

Iron

Working

Frequency Band


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It is necessary to make a good communication with the operator about the collection of

network planning data. It is very important to get the acknowledgement of the operator

for the collected data. After the original data are acknowledged, the planning work at

the next stage can be continued successfully. Also, it avoids repeated modification of

planning results due to inaccurate data input.

4.4 Identification of Base Model

4.4.1 Overview

In the radio network planning, besides satisfying the networking requirements of

operators, meet the requirements of the coverage, capacity and QoS of the planning

area with the lowest cost and flexible network solution is the direction and object of

model selection.

Model selection should comprehensively consider the type of coverage area, required

QoS, transmission model in the coverage area, equipment room condition and corollary

power transmission. The WCDMA base stations fall into macro base station, micro cell

base station, repeater and remote radio station usually. Different base stations have

different features and are applicable to different situations.

4.4.2 Requirement Analysis

4.4.2.1 Coverage Requirements

At the initial stage of network establishment, emphasize on the coverage in the

planning area first. The coverage include three aspects, point coverage, line coverage

and plane coverage and two lays, indoor coverage and outdoor coverage. Implement

the fast coverage in important areas to complete continuous coverage in the entire area

by stages. Emphasize on the outdoor coverage at the initial stage to indoor coverage

gradually.

Divide the coverage object according to the average GDP per person in the coverage

area, population distribution, geographical environment and development of

communications market. Usually, the object area is divided into 4 – 5 categories of

regions.

1. Category-1 region (extra large city like municipality directly under the Central

Government): It has such features as developed economy, large requirement for


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indoor coverage, high equipment room operation cost, continuous coverage of

high-speed service, many tall buildings in the area and large loss of radio

transmission.

2. Category-2 (important economy-developed city like capital cities): It has such

features as many hotspot and indoor coverage demand, high equipment room

operation cost and requirement of continuous coverage of high-speed service.

3. Category-3 (middle-sized city): It has such features as continuous coverage of

voice and low-speed service, low equipment room operation cost and hotspot

coverage of high-speed service.

4. Category-4 (counties and countries): It adopts large-area voice continuous

coverage in the residential area with many denizens, and in the area with a few

denizens like mountainous areas makes the plane coverage for the residential

area and line coverage for the transportation trunk.

5. Category-5 (region with few persons): In this area, adopt the line coverage for

the transportation trunk, adopt the plane coverage for the residential area and

scenic spot and adopt the low-cost broad coverage for the broad area with

activities.

The above is a general division according to the feature of the object area. A region of a

category may have different features. For example, category-2 region has some

features similar to those of category-1 region. The general features of urban area of

category-1 are similar to the features of category-2. Therefore, during the planning, it is

necessary to make a further division according to the features of the planning area, to

make the model selection more flexible and reasonable.

4.4.2.2 Capacity Requirements

The capacity of radio network should consider two factors. One is to ensure that the

capacity of radio network meets the subscriber requirement predicted for service. The

other is to ensure the capacity of the large-traffic, hotspot area, such as large shop in

the city, large office building and large entertainment places.

Capacity expansion should first consider the low-cost input mode like adding carrier

frequency and increasing the power and then consider setting micro cells in the

important area.


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4.4.2.3 Cost Requirements

In the precondition of ensuring the coverage and capacity, consider the cost of setting

up base stations. Adopt different ways to reduce the base setup and maintenance costs.

Here follow the work in the cost control:

1. Adopt the coverage object, adopt the proper base stations of some series to meet

the coverage in different situations.

2. According to the voice and data coverage object and requirements at different

establishment stages, set the site, site distance, antenna height, antenna direction

and the features of the equipment properly to meet the best economy in the same

coverage conditions. Fully learn and master the existing transmission network

resources and select the base transmission mode or repeater type according to

these transmission resources properly.

3. The channel board of base station should be configured according to the actual

traffic load. Avoid invalid channel configuration and investment waste.

4. Fully learn the basic resources of the existing network (like transmission,

equipment room and iron tower) and make the best use of them.

5. Learn the details of geographical situations of site and make a correct estimate

for the height of iron tower and other relevant measures.

6. Try to reduce the operation & maintenance costs and reduce the use of

equipment room.

4.5 Introduction to Base Stations

4.5.1 Macro BS

At the initial operation stage of the WCDMA mobile communications network, the

main object of carrier is to adopt the macro cell base stations to make the frame

networking to get the maximum geographical coverage rate. The macro cell is mainly

applicable to the large/middle-sized city with a large service capacity requirement or

focus area of some service applications. Generally, equipment room, transmission

condition, power condition and air condition are required. The macro base station is the

primary base station type in the WCDMA networking.

The macro cell has two types: indoor type and outdoor type. They can be deployed in


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the urban area with dense crowds and buildings, freeway and countryside. All

equipment supports the receiving diversity and the transmitting diversity is optional.

Indoor base stations have such features as large capacity, flexible configuration and

convenience of upgrade and expansion but they have a high requirement for the

condition of equipment room. Outdoor base stations have such features as all-weather

environment adaptation, AC power, large power and convenience of installation but

they usually have a small capacity. For the place necessary to set base stations but

without equipment room conditions, the outdoor base stations can be adopted.

The ZTE WCDMA indoor macro cell can be configured flexibly according to the

requirement. The primary models include indoor macro base stations ZXWR B18

(18CS) and ZXWR B09 (9CS), and outdoor macro base station ZXWR B09A (9CS)

for typical outdoor macro cell configuration. The configurations of equipment are listed

below:

Table 4.5-1 Indoor Macro Base Station – ZXWR B18 Equipment Configuration

Base Name ZXWR B18

Up to 3C6S. 6CS radio frequency remote station can be added

Typical Configurations In the case of 3S configuration, it supports transmitting diversity and 4-antenna receiving; In

the case of 6S configuration, it supports the receiving diversity.

Support of eight kinds of AMR voice

The uplink and downlink support PS64K, CS64K, PS144K and 384K.

The hardware supports HSDPA. Service Performance

The hardware supports the AGPS, Cell ID, and OTDOA location service.

Receiving sensitivity - 125dBm, - 130dBm@4-antenna receiving sensitivity

Downlink transmitting power 2 × 20 W and 2 × 30 W

Capacity Maximum of 1280 voice channel/rack Main Performance Indices

Iub Interface Four STM-1 and sixteen E1/T1

Operating Environment

Temperature 0 - 55

Operating Humidity 5% - 95%RH

Power Supply - 48V

Structure Dimensions 1600 × 600 × 600 (H × W × D), in mm

Weight 250 Kg in full configuration


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Table 4.5-2 Indoor Macro Base Station – ZXWR B09 Equipment Configuration

CS Name ZXWR B09

Up to 3C3S. 6CS radio frequency remote station can be added

Typical Configurations Support of OTSR, embedded transmission, embedded power conversion, transmitting

diversity and 4-antenna receiving










Temperature 0 - 55

Operating Humidity 5% - 95%RH

Power Supply - 48V



Table 4.5-3 Outdoor Macro Base Station – ZXWR B09A Equipment Configuration

CS Name ZXWR B09A

Up to 3C3S. 6CS radio frequency remote station can be added Typical Configurations

Support of transmitting diversity and 4-antenna receiving





Receiving Sensitivity - 125dBm, - 130dBm@4-antenna receiving sensitivity





Temperature 0 - 55

Operating Humidity 5% - 95% RH

Power Supply 220 VAC


60606060

CS Name ZXWR B09A



4.5.2 Micro Cell Base Station

Some dead zones still exist when using macro base stations for the network coverage

and the high traffic in the hotspot region cannot be absorbed well. Therefore, only

using the macro cell base stations for networking cannot achieve a good result. In this

case, the micro cell technology is generated.

The main features of micro cell include:

1. Small coverage range, usually between 100 m and 1000 m, or close to the

coverage radius of macro cell

2. Low overhead power of equipment, usually between 10 mW and 100 mW, or up

to 4 W and 10 W

3. Usually being installed on buildings, simple installation condition requirement

and the radio transmission largely affected by the environment

4. Small volume and convenient and flexible to install

Due to the above features, micro cells can serve as the extension and supplementation

of macro cells, which are mainly used in the two aspects:

1. Improving the coverage rate: Micro cells are mainly used in the region which

the macro cells are different to reach, such dead zones as subway and basement.

2. Improving the capacity: Micro cells are mainly used in the high-traffic area,

such hotspot areas as business street and shopping center.

In the application of improving the capacity, the micro cells and macro cells usually

constitute multilayer network together. The macro cells are mainly responsible for area

coverage and forming the lower layer of the network and the micro cells are

responsible for coverage in dead zones and hotspot areas and forming the upper layer

of the network. In the communication system configurations, micro cells and macro

cells belong to different cells.

In most cases, at the initial stage of network construction, the micro cells are scattered

in hotspot areas. The traffics are centralized, the coverage area is small and the


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improvement to the capacity is limited.

With the incessant improvement of network construction, the number of sites on the

micro cell layer increases ceaselessly. The transmission cost of micro cell in the entire

equipment investment is larger than the macro cell stations. Therefore, it is very

important to select reasonable network structure and transmission ways according to

the actual situation. The micro cell usually has 1 to 2 carrier frequencies and chain

mode is adopted between micro cells. Four to five micro cells can adopt a pair of

transmission lines to the equipment room to save the transmission cost effectively.

The primary model of the ZTE micro cell base station is ZXWR B03C, whose

configurations are listed below:

Table 4.5-4 Micro Base Station – ZXWR B03C Equipment Configuration

Base Name ZXWR B03C

Up to 3C1S. 3CS radio frequency remote station can be added Typical Configurations







Downlink Transmitting Power 2 × 10 W and 2 × 20 W


Iub Interface One STM-1 and four E1/T1


Temperature 0 - 55





Micro cells can either serve as basic coverage or supplementation of coverage. They

can increase with the total of traffic and implement point-to-plane multilayer coverage,

to improve the capacity and performance of network gradually. The use of micro cell

increases the complexity of network, difficulty of planning and construction cost.

However, the micro cell technology can make the best use of limited frequency


62626262

resources to realize continuous increase of service. Therefore, the use of micro cell is

the necessary result of the development of the WCDMA mobile communication

network.

4.5.3 Remote Radio Station

The remote radio station separates the radio unit and baseband unit. One base band unit

can be connected with multiple radio units through fiber. The radio units can be put in

different places as required to realize the flexible coverage mode. In this case, the

remote radio mode separate the base station into units and make the radio units in a

good place to resolve the coverage in particular regions.

The remote radio base station is draw the macro cell base station to the remote through

fibers to realize the remote coverage. It falls into radio signal remote mode and

intermediate frequency mode. Due to its flexible system structure, it can be applied to

various kinds of radio environment, including the indoor coverage in the buildings in

the urban areas, coverage of shadow area in the urban areas and coverage in the

outlying area. It can save investment and be applied flexibly.

The Node B system can be divided into radio remote module and local base station, as

shown in Fig. 4.5-1.

Local radio unit

Remoteradio unit

Remoteradio unit

Remoteradio unit

Remoteradio unit

Basebandprocessing unit

Fig. 4.5-1 Radio Remote Structure


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The primary model of the ZTE radio remote base station is ZXWR B03R, whose

configurations are listed below:

Table 4.5-5 Remote Radio Station – ZXWR B03R Equipment Configuration

Base Name ZXWR B03R

Maximum of 3C1S Typical Configurations






Receiving Sensitivity - 125dBm, - 130dBm@4-antenna receiving sensitivity

Downlink Transmitting Power 2 × 10 W and 2 × 20 W


Iub Interface One STM-1 and four E1/T1


Temperature 0 - 55





4.5.4 Repeater

With the incessant development of WCDMA mobile communications network, the

coverage problem in indoor dead zones becomes serious. The enhancement of planning

optimization will resolve the problems easy to be found through test in the outdoor

areas basically. The center of communication network construct will shift from the

outdoor coverage to indoor coverage.

There are three ways to realize the indoor coverage:

1. The outdoor macro cells provides the indoor coverage in their coverage range,

which is the most common method adopted in China at present.

2. In case the outdoor macro base stations have redundant capacity, use the repeater

to introduce the signals into the indoor area, covering the indoor dead zone

through the indoor coverage system.


64646464

3. In the place centralized with traffics, set indoor micro cells and remote radio unit

to resolve the coverage and capacity problems together.

The top buildings are dense in urban areas. The way of providing indoor coverage with

outdoor station has much limitation. In case only using the outdoor station to ensure the

quality of indoor coverage, the signal interference in the outdoor area becomes serious

and difficult to control and even affect the overall planning and network performance

of the network. Moreover, for large areas like shop and entertainment center, only

using outdoor stations cannot achieve a good result.

Using micro cell to resolve the coverage of indoor dead zone has large limitation also.

The equipment input for the micro cell construction is large and the project period is

long. So, it is more suitable for the luxurious auditoria and shop with centralized

traffic.

Due to its flexible and simple features, the repeater becomes an important way to

resolve simple problems, which is often used in places with a low requirement for

capacity, such as small shop and restaurant.

The repeater is mainly used in the following occasions:

1. Expand the service range and eliminate the coverage dead zone.

2. Enhance the field strength in suburb and expand the coverage in suburb.

3. Set the repeaters along the freeway and increase the coverage rate.

4. Resolve the coverage problem of indoor coverage.

5. Realize busy indication.

When installing the repeaters, it is very important to select the antenna feeder system.

Pay attention to the following points:

1. Antenna gain: According to the signal and coverage requirements, select the

proper gain.

2. Antenna direction: Because the repeater belongs to the intra-frequency, the

omni-directional antenna cannot be adopted. Otherwise, it may cause the

spontaneity of system. The main lobe brand of donor antenna should be as

narrow as possible to reduce the introduction of noise. The transmitting direction

of retransmission antenna should be controlled strictly, to prevent the

retransmission signals from being fed into the donor antenna.


65656565

3. Signal source base: Select the base station with a good quality of signal as the

feed-in source and ensure that the capacity of the base station is large enough.

Otherwise, congestion may occur.

The repeater is an economical and practical solution. The installation of repeaters is

simple and flexible, the models are diversified and the application range is broad. The

repeater is a supplement to the WCDMA communications network construction. Such

places can adopt repeaters as required as hotel, shop, underground park and subway in

the city as well as suburb, villages and towns, countryside, road, railway and scenic

spot. The transmission diagram of repeater in the mobile communications network is


Coverage area of base station

Donor base station Repeater

Coverage areaof repeater

Fig. 4.5-2 Transmission Principle of Repeater

4.5.5 Others

Besides being categorized by equipment type, the base stations can be categorized by

logical structure, falling into omni-directional base station, single-sector base station,

two-sector base station, three-sector base station and multi-sector base station. The

selection of base station model is determined according to the requirement of radio

coverage and traffic load. In the urban areas with large traffic, the three-sector base

station is usually adopted. In the broad area of suburb, to improve the coverage, reduce

the interference and facilitate the network optimization, adjustment and control, it is

suggested for adopting the sectorized base stations in principle. In the coverage area of

small region which is relatively isolated, for example, basin, the omni-directional

repeater can be adopted. For the area of strip-type coverage such as road and valley, the

two-sector base station can be adopted. Particular coverage requirement can select

multi-sector base station as required, for example, besides macro coverage, the separate


66666666

sector can be selected for coverage of surrounding buildings or shadow.

Moreover, at the initial stage, adopt the power splitter to split the base stations in

suburb and small towns into multi-sector antenna transmission or receiving.

Omni-directional TX Sectorized RX (OTSR) is to resolve the unbalance problem

between uplink and downlink in the case of small network capacity. On the one hand, it

reaches the coverage effect of sectorized base stations and on the other it saves the

investment of equipment. In the subsequent project, according to the traffic load,

upgrade the base stations into the sectorized equipment conveniently.

4.6 Networking Schemes in Typical Surroundings

The networking schemes only provide the possible networking modes. To select a

networking scheme, it is necessary to consider various kinds of factors

comprehensively, especially combining the actual radio transmission environment in

the communications network planning region. On in such way, the best coverage and

capacity can be ensured.

4.6.1 Basic Coverage in Urban Areas and Traffic-Den se Areas

Coverage features:

1. The service demands are centralized, so the equipment should have a large

capacity and high processing capability.

2. The network coverage has a high requirement, so the equipment should have a

flexible coverage capability.

3. Due to the space limit of equipment room, it is necessary to select the equipment

with a small volume.

4. To meet the new service demands sensitively, the equipment should have the

development capability.

On the basis of the coverage features in the service-dense areas, adopt the indoor or

outdoor macro cell base stations of primary models in networking. To use the top

buildings in urban areas or the equipment room of traditional GSM and CDMA base

stations, it is necessary to make the service plan and network plan for site construction.

The capacity of base stations can be adjusted according to the service density and

penetration loss of the coverage area. For the area with high service density, such as


67676767

airport, station and business district, the coverage radius of base stations can be

reduced and the capacity of base stations can be expanded properly. Adopt the

penetration coverage to cover the indoor dead zones in the building and adopt the

Metropolitan Area Network (MAN) transmission optical ring for transmission, in

particular cases, adopt the microwave link.

Due to the dense GSM and CDMA base stations in the urban areas and short of site

space resources, the difficulty of the planning of the WCDMA communications

network increases and the site range available is smaller. The traditional

communications operators have cell equipment rooms but the cubage situation is poor.

However, new mobile communications operators need to set up new sites. But the

difficulty of setting up new sites increase more and more – with the improvement of

people’s living standard, people are more sensitive to the radiation harm from the radio

communication and they are not willing to lease their property to mobile

communication operators for setting up sites, and in result the difficulty for selecting a

new site increases greatly. Moreover, in the developed city, the property rent of site is

30,000 to 50,000 RMB every year, which make the mobile operators spend more

operation costs.

Therefore, new site setup should be considered carefully. The market competivity of

macro cell base stations of primary models for new site should be enhanced. The

primary models should be applicable to both indoor equipment room and outdoor

environment (such as terrace). Such base stations have a large capacity, can realize

several times of expansion in a cabinet and support fiber remote radio function.

4.6.2 Coverage in Suburb and Countryside

Coverage features:

1. The buildings are scattered, the path loss is small and the coverage distance is

large.

2. The traffic is low and income is small. It requires large investment but generates

a small income. The efficiency of building network is low.

3. The range and coverage is broad, the number of sites is small, the sites are

distributed broadly, the landform is complex and the maintenance is difficult.

4. It is outlandish. The corollary equipment such as transmission equipment, power

supply, equipment room and iron tower are difficult to resolve.


68686868

The base stations in suburb and countryside should meet the coverage requirement first

and then the capacity requirement. The outdoor small integrated macro cell base station

can be adopted. The installation and setup are convenient, especially applicable to the

site environment from away from city and the location not providing DC power. Set up

iron towers or adopt the economical drawing tower or set up site in the proper

geographical location (like highland or peak of mountain). The capacity requirement

for base stations is not high. One or two carrier frequencies are used to meet the

large-area coverage requirement primarily. The transmission can adopt the microwave

link or fiber.

4.6.3 Coverage in Particular Surroundings

Particular surroundings here refer to shop, hotel, business building, exhibition hall,

gymnasium, industrial park, campus of college, station, airport, park, tunnel and

subway. In these surroundings, the radio signals may have four poor aspects: dead

zone of signal, weak zone of signal, conflict zone of signal and busy zone of traffic.

1. Dead zone of signal

Reason: The materials of buildings (like solid, thick armoured concrete) have

the shield function. They make the signal level lower than the receiving

sensitivity of mobile phones after the signals transmitted from outdoor base

stations going through the path loss and penetration loss of buildings, causing

abnormal communication for mobile phones. The typical areas of dead zone are

basement and subway.

2. Weak zone of signal

Reason: The materials of buildings (like armoured concrete and glass curtain

wall) increase the penetration loss of radio surroundings. They make the signal

level close to the receiving sensitivity of mobile phones after the signals

transmitted from outdoor base stations going through the path loss and

penetration loss of buildings, causing poor communication quality for mobile

phones. The typical area of weak zone is in the large-scaled buildings.

3. Conflict zone of signal

Reason: Due to the limit of frequency resources, reduce the base coverage radius

to improve the network capacity and multiplexing of frequencies. It limits the

antenna height. In this case, the radio signals in the top buildings may come


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from many cells (most are unstable reflection signals from the ground and wall).

It will cause the frequent handoff (ping-pong effect) and even affect the normal

communication of mobile phones. Typical area of signal handoff is top buildings

(area above 15 floors).

4. Busy zone of traffic

Reason: In some areas with a large people flow, there are many mobile

subscribers. The capacity of outdoor macro cell base stations cannot meet the

communication requirements, leading to block of communication and in result

subscribers unable to access the mobile communications network for normal

communication. The typical area of busy zone includes large business district,

gymnasium, exhibition center and station.

It is necessary to analyze the specific situation of the above problems. For dead zone

and weak zone, resolve the poor signal source problem by setting up intra-frequency or

inter-frequency indoor micro cell, repeater and remote radio station. On this basis, use

the indoor antenna system to distribute the radio signals to different indoor places

equably. The indoor antenna system includes passive coaxial distributed antenna

system, active coaxial distributed antenna system, fiber distribution antenna system and

leaky cable. In the application, they can be adopted flexibly according to the actual

situation. The problem of conflict zone can also by resolved by laying out the indoor

distributed system. In the dead zone, resolve the problem of super large capacity

requirement through the hierarchical networking mode. On the basis of macro base

station coverage, set up the inter-frequency micro cell to absorb some traffic to lessen

the capacity pressure.

4.6.4 Coverage along Freeway and Railway

Coverage features:

1. The coverage area is of strip-type. There are no buildings almost, the path loss is

small and the coverage distance is large.

2. The block from landform may exist, for example, the shadow of mountain.

3. The number of subscribers is small but they have the data service requirement.

4. The corollary equipment is difficult to equip, the efficiency of constructing

network is low and the maintenance is difficult.


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The landform along freeways and railways are complex and diversified. During

implementing the seamless coverage of freeways and railways, the following points

should be considered in the base model selection:

Try to adopt macro cells in the place where the large-area coverage can be realized like

plain and town. You can also install tower amplifiers to expand the coverage range. Set

up sites on the corner of roads in a mountainous area to reduce the block of mountain.

If the road beside the corner is straight, adopt the proper antenna to make the base

station cover a longer distance. You can use the macro cell bi-directional base station or

single-cell bi-directional base station. Try to adopt the omni-directional base station

(the traffic not close to the road and railway section of town is small, omni-directional

station is simple and economical) in the case of being able to meet the coverage

requirement. For the mountainous areas with block, you can adopt the repeater. When

setting up sites in the mountainous areas, you can embed the micro cell in the macro

cell or use the repeater to realize the continuous coverage or signals.

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5 Tools using in the Survey of Network Planning

5.1 GPS Principle & Application

5.1.1 GPS Structure

GPS is the Global Positioning System established in 1994, comprising space

constellation, ground monitoring and user equipment.

There are totally 25 satellites for GPS at present, running on six elliptic orbits more

than twenty thousand kilometers above the ground.

5.1.2 GPS Principles

Working principle: The receiver tracks, captures and locks the satellite signals through

phase, collects satellite ephemeris, measures the pseudo range, calculates the latitude,

longitude and altitude of the position where the receiver resides. The 2D positioning is

applied in capturing three satellites and the 3D positioning is applied in capturing more

than four satellites. The precision for positioning becomes higher with more and more

satellites captured.

5.1.3 Name and Function of the GPS Panel Keys

5.1.3.1 GPS12C/GPS12XLC Panel

Tail of the instrument

Displayare

Operationarea

Fig. 5.1-1 Schematic Diagram of the GPS Panel


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5.1.3.2 Name and Function of the Keys

Table 1.1-1 Name and Function of the Keys

SN Key Name Function

1 Bulb key For switching on/off the machine and controlling the strength of

the backlight of the L3 screen

2 Page Up/Down

key

For displaying the main pages in cycle or returning to the main

page from a sub-page.

3 Enter For activating the highlighted part, confirming menu options and

inputting data

4 ESC key For displaying the previous page or recovering the value of the

selected data area

5 Label key For marking the current position as a way point

6 Navigation key For reaching to a way point directly

7 Up, Down, Left

and Right key

For moving the cursor upward, downward, to left and to right, and

the Up and Down can help select digits and letters

5.1.4 Basic Operations

Note

To make your operation indoors easy, select Function setting > Operation > Mode >

Similator.

5.1.4.1 Bring-up, Bring-down, Illumination and Powe r Supply

Bring-up: Hold the GPS and set the level of its internal antenna facing the sky.

Constantly press the bulb key for about one second, and a bring-up page appears and a

satellite capture (receiving status) page is displayed, as shown in Figure 2a.

Brightness adjustment: Press the bulb key to adjust the backlight of the screen. This

function is only used at night or in poor light.

Bring-down: Press the bulb key for about two seconds.

The instrument applies four No.5 batteries. To change the batteries, bring down the

machine and turn the metal ring at the tail of the instrument, as shown in Figure 1, to

take out the batteries. Upon completion, bring up the machine.

5.1.4.2 Initialization Setting

GPS12C/GPS12XLC is the concurrent 12-channel receiver with a high sensitivity, and


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it can locate fast without any initialization generally before use. In addition, it has a fast

initialization functions, including AUTO-LOCATE (automatic location), COUNTRY

(country selection) and continuous research (NONE-INIT).

Tips: Bring up the machine, and the picture showing the satellite status pops up. Press

Enter to enter the menu of initialization mode selection.

Initialization is necessary in the following cases. If you know the approximate latitude

and longitude coordinate of a position, you may input the latitude and longitude in the

navigation page to accelerate the location speed.

1. The first use after delivery.

2. The receiver keeps away from the previous satellite after its power-off, for over

500 miles.

3. The memory of the receiver is cleared and the data stored in it are lost.

5.1.4.3 Establishment of Way points

1. After the completion of positioning, press the label key to enter the page for the

marked position.

2. Point positioning for average value (This step is optional, but recommended in

general)

3. Press the Up/Down key to move the cursor to the way point. Press Enter to enter

the input status. Press Up/Down key to input the name of way points to be used

(constituted by letters and numbers, in the form of area name abbreviation + way

point name abbreviation, six bits at most)

4. Press Enter to move the cursor to the saving place, and press Enter for

confirmation.

5. In the marked position page, there is another line for adding a navigation line, in

which the name of a navigation line is entered.

Hereto, a way point and a navigation line have been established. To return to the page

for function setting by pressing the Page key, select the nearest way point menu to see

the straight-line distance and the azimuth angle between the current position and the

nearest established way point, this value cannot be saved for long but updated in

real-time along with the changes of the position. Keep records in real-time if you need

it.


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The nearest navigation-point function is very useful to the real-time measurement of

the distance and the angle between the way points, so it is highly recommended.

5.1.4.4 Point Positioning for Average Value

This function is aimed at improving the precision of point positioning and minimizing

the error.

The detailed operation is as follows:

1. Press the positioning key to enter the Marked Position page.

2. Use the Cursor key to move the cursor to Average, highlight it, and then press

Enter. In this case, the machine becomes smooth.

3. The smaller the smooth reference value at the Error is, the higher the precision

becomes.

4. If the digit at Error is fixed or reaches the expected value, move it to Save, and

press Enter to complete the saving.

5.1.5 Basic Information

a b c d

Fig. 5.1-2 GPS

5.1.5.1 Page for Receiving Satellite Signals

It is the first page shown after bring-up, as shown in Figure 1.4-1a. Below is the

description of it:

1. The figure shows the distribution of satellites.

2. Satellite direction: North upwards and south downwards, west to the left and

east to the right


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3. Satellite elevation angle: Its center is equivalent to the right top of the place

where a satellite resides. The big circle represents the horizon, and the circle in

the middle is in a 45o pitch. The elevation angle becomes larger when the

satellite comes closer to the center.

4. Satellite number: The numbers in the figure indicate the satellites in the upper

part of the horizon, and the highlighted numbers mean not receiving the satellite.

5. Black-bar diagram: indicates the strength of the received satellite signal, and the

higher the black bar is, the stronger the signal becomes. If there is no black bar

but box bar, this satellite is in the tracing state. Once the box bar is locked, it

will become the black bar. If there are no black bar and box bar, the signal of

this satellite is not received. Generally speaking, the nearer the satellite in the

circle comes to the center, the larger the pitch of the satellite becomes, and the

stronger the received satellite signal becomes.

6. Indicator of battery voltage: There is a black bar to the upper left, which

represents the battery voltage. If the battery electric voltage is high, the black

bar is long.

7. EPE value: Located at the upper right corner, indicating the current estimated

positioning error in the unit of M or FT.

8. The upper left corner indicates the current working status of the receiver,

including:

9. Satellite search: GPS is searching the visual satellites.

10. Capture satellite: GPS is receiving information from the visual satellite, but it is

impossible to calculate the 2D position based on the current information.

11. 2D navigation: The machine can implement the 2D positioning until it receives

at least three satellites with a good geometric factor. For example, it displays

“2D DIFF” (2-dimensional difference) in the case of differential status.

12. 3D navigation: The machine can implement the 3D positioning until it receives

at least four satellites with a good geometric factor. For example, it displays “3D

DIFF” (3-dimensional difference) in the case of differential status.

13. Use failure: the incorrect initialization or abnormal satellite status. The receiver

cannot be used, so it should be shut down for initialization.


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5.1.5.2 Data Query

Description of the positioning page, as shown in Table 5.1-1b, as shown in the table

below:

Table 5.1-1 Description of Positioning Page

Sequence Meaning

Line 1 Direction staff: direction of the course and inclination with the north direction

Line 2

Digital representation of course and speed. The meaning of course is the same

as that in Line 1, only differing in representation; the course and speed cannot

be used unless the receiver runs, it means the direction of speed of the current

movement. Its angle increases starting from 0o.

Line 3

Voltage and height: Voltage has the functions of an odometer. Height is

valid upon 3D positioning, through which the relative height of two different

way points can be measured.

Line 4 The latitude and longitude value for the current receiver position.

Line 5 It is the current GPS time. The satellite clock time-telling is applied, without

the need of changing and correction.

Caution:

In the process of positioning, observe the precision of GPS (EPE value), which should

be less than five meters, in the following ways:

The first way is to capture the EPE value at the upper right corner of the satellite page,

as shown in Table 5.1-1a.

The second way is to press the label key to enter the marked position page, and use the

Up/Down key to move the cursor to Average. Press Enter and the GPS starts to

calculate the average value until the number at Error is fixed or reaches the expected

value.

5.1.5.3 Track Page

1 This page is used to display the your position and track.

2 The upper left of the page is the scale. Press Enter here, and the mantissa of the

number becomes dark. Press Up/Down key to adjust the scale range (0.5 KM –

600 KM) you need. Press Enter to exit after selection.

3 The up/down arrow in the upper middle part is the cursor key. Press Enter here

and press the cursor key to move pictures. In this case, you select any one point


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for positioning.

4 At the “Pencil head” in the upper right end of the picture page, you can set the

tracks and graphs.

5.1.6 Navigation Operation

5.1.6.1 Navigating by Navigation Pages

1 Press the navigation key to show the way point page.

2 Use the up/down/right/left key to select the number or name of the way point to

be reached.

3 Press Enter for confirmation, and GPS automatically returns to the navigation

page, and it can calculate the azimuth, distance and mileage from the place

where you reside and the way point.

5.1.6.2 Starting Navigation

1 Use the page key to turn to the compass or expressway page. Press Enter to

show a selection menu, and press Up/Down key to select a compass or an

expressway. Press Enter to select them into the appropriate page (the compass

page is shown in Table 5.1-1c).

2 In the compass page, on the right top is the name of the way point to be reached,

in the middle is a compass display, and the arrows show the angle of deviation.

The arrow pointing to the right top indicates no deviation of the angle. There are

such information as orientation, distance, course and speed.

3 The course is displayed in the expressway page, and the four kinds of

information displayed in the upper part is the same as above.

5.1.6.3 Removing a Way-Point

1. Press the page key to turn to the page of function setting, as shown in Table

5.1-1d.

2. Press the up/down cursor key to the options of way-point and press Enter to

show the way-point page.

3. Press the up/down key to select the way point to be removed, and press Enter to

show a selection menu, and then press the up/down key to select Remove; press

Enter to show the query page, press the up/down cursor key to select Yes, and


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press Enter to remove this way point.

4. In the way-point page, there is the option for removing all way-points. Select it

to remove all the way-points (applying it with care).

5.1.6.4 Navigating by Courses

1. Set up the way points on the course, or directly use the originally set way points.

2. Press the page key to enter the function setting page, as shown in Table 5.1-1d.

Press the up/down key to select a course, and press Enter to enter the course

page.

3. Select a course number and press Enter.

4. Press Enter for confirmation, and the cursor automatically moves to the next line.

Press Enter to input the way-point number. Press the up/down/right/left key to

input a way point, and press Enter for confirmation after the completion of

input.

5. After inputting all the way points in the above way, you can set the direction of

the course in the bottommost line, positive direction or opposite direction, and

you can clear this course. Positive direction means starting from the first

way-point of a course and navigating in the positive direction.

6. Course change: includes the clearance, modification, addition and deletion of a

course. In the course page, select a course number to be modified, and press the

up/down key to select a way point to be modified. Press Enter to enter the

modification page, and then press the up/down key to select the way of

modification. Press Enter for confirmation.

5.1.7 Function Setting

GPS has a complete set of functions. Mastering the function setting is the key for using

this machine, which is sure to meet your different requirements. For the input method

of function setting, refer to Basic Operation.

Below is the description of the common function setting. For the function setting page,

refer to Table 5.1-1d.

5.1.7.1 System Setting

1. MODE: Normal: The receiver receives satellite signals to locate and navigate;


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Simulator: Used for contact at home and input of way points and courses, in this

case, the receiver does not receive any satellite signals.

2. OFFSET: You can input the local time-zone number. For example, China should

be in East Time Zone: 8h East, that is, input +08:00.

3. CONTRAST: Adjust the black-white contrast of the screen; press Enter to adjust

through the left/right key.

4. LIGHT: Set the duration of the backlight, ranging from 0 to 240 s at six levels.

5. TONE: Three settings, no prompt tone, information prompt, information and key

prompt tone, MSG and KEY.

5.1.7.2 Navigation Setting

1. Format of marked positions: way of displaying the positioning result, which is

generally set as hddd.ddddd°, that is, the degree form.

2. (Coordinate system) MAP DATUM: Set as WGS84 in general

3. UNITS: for those navigation parameters as distance, speed and so on, which are

in three systems: metric system, marine system and British measurement, but the

metric system is recommended.

4 Direction: Definition of the positive north. There are four kinds, automatic,

positive north, user-defined and gridding.

5.1.7.3 Interface Setting

There are five ways of the GPS input/output: None/None,NMEA/NMEA,

GRMN/GRMN,RTCM/—— and RTCM/NMEA. NMEA/NMEA is selected generally.

1. NMEA/NMEA: GPS outputs the information about satellite positioning under

the globally standard NMEA0180,0182 and 0183 (1.5/2.0) protocols.

2. GRMN/GRMN: GPS owns the dedicated transfer protocol of GARMIN and can

transmit information about way points, courses and satellite ephemeris with

other types of GARMIN receiver; it can be equipped with the PCX5 software of

GARMIN and can transmit the above information between it and PC, which can

be downloaded and uploaded.

3. RTCM/——: receives the real-time differential correction data of RTCM

SC-104 2.0, and the Baud rate can be freely adjusted from 300 to 9600. The


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GPS precision after difference can reach 1 to 5 m.

4. RTCM/NMEA: The receiver RTCM outputs the NMEA data while differencing

signals, and can adjust the parameters such as frequency and data transmission

rate for receiving the GBR21 beacon of GARMIN.

5.1.8 Performance Specifications

5.1.8.1 Physical Indices

1. Shell: Water-proof, sand-resistance and quake-proof, under the American

MIL-810 Standard

2. Dimensions: 12.4 mm x 13.3 mm x 6 mm

3. Weight: 0.255 kg

5.1.8.2 Battery Indices

1. Power consumption: 0.75 miliwatt (no backlight used) in normal case

2. Power supply: 5 ~ 40 VDC (GPS12XLC)

3. 5 ~ 8 VDC (GPS12C)

5.1.8.3 Environmental Parameters

1. Operating temperature: -25°C ~ +75°C

2. Storage temperature: -40°C ~ +80°C

3. Humidity: 95% not condensed

5.1.8.4 Performance Features

1. Receiver: 12 parallel channels, which can simultaneously track 12 satellites.

2. Search time: Hot startup: 15 second; cold startup: 30 seconds; automatic

positioning: 75 seconds; sky searching: 2.5 minutes; re-capturing: 1 second.

3. Positioning: 10 m.

4. Speed precision: 0.4 kts RMS (at the regular speed).

5. Dynamic: Limited speed: 999 kts; acceleration limit: 6g; Jerk limit: 61m/s3.

6. Interface: NMEA0183 output; RTCM real-time differential input.

7. Storage point: 500 way points; 1,000 track points


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5.2 Principle and Application of a Laser Rangefinde r

Knowledge

This chapter involves the principle and application of a laser rangefinder.

5.2.1 Name and Function of the Panel Keys on a Lase r Rangefinder

5.2.1.1 Schematic Diagram of a Laser Rangefinder Pa nel

3 Measurementreference edge

5 Distance measurement,tracking

6 Multiply [x]/delaymeasurement

9 Clear (return-to-zero)

10 Switch11 Equal, Enter

12 Minus [-]13 Pythagorus'theorem

function14 Minimum/maximumtracking measurement

15 Store/save

Keyboard

Fig. 5.2-1 Rangefinder Panel


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5.2.1.2 Schematic Diagram of Display

1 Laser started

Di spl ay scr een

2 Measurement reference edge (Leadingedge/instrument support/trailing edge)

3 Information4 Calculation display5 Primary display (such as: thecurrently measured distance)

6 Distance measurement7 Tracking measurement

8 Area/dimension

9 Minimum tracking measurement

10 Maximum tracking measurement

11 Pythagorus'theorem function

12 Using the Pythagorus'theorem tomeasure the partial height

13 Units, including power and cube (2/3)

14 Countdown display for delay measurement

15 Storage constant

16 Contact with the repair personnel

17 Three extra displays (such as:Measurement mean value)

18 (SET) Exit from the setting

19 (Reset) Restore to factory settings

20 Display of battery recharge volume

21 Constants for invoking storage (10 at most)

22 Invoking the last 15 measurement values

23 Illumination (on/off)

24 Buzzer (on/off)

25 Measurement with constants

Fig. 5.2-2 Rangefinder Display

5.2.2 Operation Description

The laser rangefinder is shown in the figure below:

Fig. 5.2-3 Rangefinder Display


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5.2.2.1 Battery Installation/Replacement

1. Press the dismount button and push the back cover to the right and take it out.

2. Open the battery slot cover and put the batteries in.

When the electrical voltage of a battery is too low, there will be this signal on

the display.

For the model of battery, refer to Technical Parameter.

Correctly install the batteries by polarities.

Only the alkaline battery can be used.

3. Insert the back cover in along the slot until it reaches the right position.

5.2.2.2 Enabling/Disabling DISTO

Press the button quickly.

The illumination, battery charge volume and buzzer are displayed until the first work

command is delivered.

This instrument can be shut down in any menu at any time.

The instrument will be automatically shut down if the keyboard is unused within

90 seconds.

5.2.2.3 Clear Key

It can restore the instrument to the normal mode, t hat is, restore it

to zero (= clear).

The clear key can be used before/after measurement/calculation.

In a function (area or dimension), the clear key can be used to return to the previous

instruction for measurement.

5.2.2.4 Illumination


This button can be used to control the illumination.

The illumination will be automatically shut down if the key is unused in 30

seconds.


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5.2.2.5 Setting the Measurement Reference Edge

Constantly press it until the needed reference edge appears.

The possible position of the reference edge:

Leadingedge

nstrumentfulcrum

Trailing edge

Fig. 5.2-4 Measurement Reference Edge

1. There is a junction for the 1/4 camera tripod at the back of an instrument.

2. The setting of the measurement reference edge cannot be changed unless it is

done again or the instrument is shut down.

3. If set by the manufacturer, the measurement reference edge is rear edge.

5.2.2.6 Measurement

1. Distance for measurement

Press this button to start the laser. In this case, the instrument is in pointing

mode.

Press it for the second time to measure the distance.

After this, the measurement results can be displayed on the screen in the selected

unit.

The instrument is started but the laser is not. In this case, it is called

Normal-mode.

When the laser is also started, it is the pointing-mode.

2. Measurement made on the surface of the plane.


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Fig. 5.2-5 Plane Measurement

Turn an angle of 90o to stably place the instrument onto the measurement

surface.

3. Measurement from a corner

Fig. 5.2-6 Measurement from a Corner

Constant (tracking) measurement

Constantly press this button until it is displayed on the screen.

The constant measurement starts and the real-time distance is displayed on

the screen.

Press this button to end the constant measurement. The last result is

displayed on the screen.

For example, distance measurement

Fig. 5.2-7 Tracing Measurement


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4. Constant emission of laser

Constantly press this button until you hear a long buzz. At this time, the

laser is constantly started.

After this, press this button every time to make a measurement.

Press this button to disable the constant emission of laser.

Delayed measurement

In this case, it must be in reading mode.

Press this button until the time for delaying measurement that you hope

appears (60 seconds at most).

is displayed on the screen.

Release this button to display the time left for the measurement (counted down

as 59, 58, 57…), and the last five seconds are elapsed along with buzz.

For example, the measurement without using keys

Fig. 5.2-8 Measurement Without Using Keys

5.2.2.7 Area Calculation

1. Area

Constantly press this button until is displayed on the screen.

The side to be measured flashes.

The measurement should be made two times and the results of them are

displayed on the screen.


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2. Volume

Press this button until

is displayed on the screen and the side to be measured flashes.

The measurement should be made for three times (H x W x D).

The area and the result of the three measurements are displayed on the screen.

5.2.2.8 Menu/Setting

This instrument can be set as per your needs.

Fig. 5.2-9 Special Setting

1. The measurement with the added constant (plus/minus)

2. Unit setting

3. Buzzer (ON/OFF)

4. Reset

1) Start menu

Constantly press this button until the menu options you need are

displayed, or press the (+ —) key to select the menu options you need.

This button is for confirming your selection and making the menu

option you selected valid.

Press this button or press the (+ —) key to change your selection.

This button is for confirming your selection and restoring the normal

mode.


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Here, you may also use the reset key, such as clearing your selection.

2) Unit setting

Units available for your selection:

Fig. 5.2-10 Units Available for Selection

3) The measurement with adjustment values

Fig. 5.2-11 Measurement with Adjustment Values

4) Start menu option

Flashes on the display. Use the (+ —) to select a value to be adjusted (equivalent

to the adjustment of measurement reference edge), such as 0.015 mm; press this

button to select it fast.

Press this button to make a big adjustment.

The adjustment value can be a positive one or a negative one.

This button is for confirming the setting.

When the adjustment is not a zero, the display will constantly show this

value.

The measurement result can include the adjustment value.


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Using this function can help measure the skeleton.

Please form a habit of restoring the adjustment value of DISTO to 0.000 after

the measurement of the skeleton, and the procedure is as follows:

Press this button.

Confirm a function.

Make an effective measurement after reset or restoration.

5) Reset.

Start a menu option.

flashes on the display.

Use the (+ —) key to select the items to be restored, including:

Store/save.

Storage and constant measurement.

When there are more things in the display such as measurement reference unit,

the following values can be restored:

— measurement with constants added (=0), buzzer (enabled), unit (m)

The selected item is restored and the test mode returns.

5.2.3 Function

5.2.3.1 Saving the Measurement Value (Constant)

1. Measurement/calculation of the values you need (such as, height, area,

dimension)


Flashes on the display.

Use the (+ —) key to set the needed values (from 2.297 to 2.300)

Press this button simultaneously to make a big adjustment.


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Press this button to adjust units (2/3).

This debugging is only applicable to , and or

Confirm

A digit (= memory address) flashes.

Use the (+ —) key to select the memory address (0 - 10).

Save;

2. Invoke the constant again.


The first stored constant is on the display (such as 2.300).

Use the (+ —) key to select the memory address (1-10) you need.

Confirmation. This constant can continue to be used (such as calculating

areas)

3. Invoke the last one measurement value (constant).

Constantly press this button for two times.

The last one measurement value will be displayed in the screen.

Use the (+ —) key to select the constant (15 at most) you need.

Confirmation. This constant can continue to be used (such as calculating

areas).


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5.2.3.2 Tracing Measurement – The Minimum Value

Confirm the minimum measurement value, such as, measure the height of a room

without confirming a right angle.



Use DISTO to roughly aim at an target.

Press this button quickly to start the constant measurement function.

DISTO shakes around the target in a wide range.

Press this button to stop measurement.

At this time, the minimum measurement value is displayed (such as, 3.215 m = room

height).

Two planes (such as, floor/ceiling, wall) must be in parallel basically.

5.2.3.3 Tracing Measurement – The Maximum Value

Determine the maximum measurement value, such as:

Determine the opposite angle of a room.


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Use DISTO to roughly aim at an target.

Press this button quickly to start the constant measurement function.

DISTO sweeps the opposite angle slowly to left/right.

Stops the constant measurement.

At this time, the maximum measurement value is displayed (such as, 12.314m = the

length of the diagonal line in the room).

5.2.3.4 Calculation Function, Partial Height, Parti al Measurement Setting

Press the (+) key to make the plus/minus calculation. Make the measurement again.

= Result.

The same method can be used to implement the serial measurement (multiple

measurements needed), or to add multiple area/dimension results together.

In any step of the calculation process, return-to-zero can be achieved before the

calculation result is obtained.

Multiply

Measure (such 8. 375 m)

Implement the function of the multiply key (x).

Continue to measure (such as 3.500 m)

= area (such 29.313)

After obtaining the area, this function can continue to be used for dimension

calculation. This function is to use partial height/measurement setting to obtain the

area/dimension.

5.2.3.5 Measurement Value Doubled

It can double the measurement value in a very convenient way, for example, to obtain


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the perimeter of a room.

Use the (+) key for addition.

Continue to measure.

= result (half the perimeter)

Use the (+) key for repeating.

= result (perimeter).

5.2.3.6 Using the Pythagorean Proposition for Heigh t and Width

You must make the measurement following the order below.

Two or three measurement points should be vertical (level) to the wall.

Each distance measurement is OK.

- Simple measurement

- Storage of measurement constants

- Using the delay measurement

For the short-distance measurement, the measurement ruler can be used.

Use the fixed rotation point (rear edge, fulcrum of the instrument) to make the laser

rotate with the rotation point as the axis, thus improving the measurement precision.

Do not place it on the camera. On the cameramount, the laser is 70 to 100 mm away

from the rotation point, which may result in an obvious deviation.


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5.2.3.7 Measurement Based on Two Points

Obtain the height/width of a building. When the result of height should be obtained

after two or three measurements, the measurement can be made in the former place

without the need of setting up a support.


is displayed in the screen, the laser is started and the display flashes with “1—”.

The above point displays (1).

Under measurement. Do not shake!

Result display

“2—“ flashes, displaying that the DIST is approximately parallel with (2).

Press this button to make the constant measurement.


Stop measurement. The needed height or width is to be displayed.

5.2.3.8 Measurement Based on Three Points


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Result display

“2—“ flashes, displaying that the DIST is approximately parallel with (2).

Press this button to make the constant measurement. DISTO shakes around the

target in a wide range.

Stop measurement.

The measurement result is displayed and “3 —“ is displayed in flashes.

Aim at the third point.


All the heights or widths can be displayed.

5.2.3.9 Measurement of Partial Height Based on Thre e Points

Use three measurement points to obtain the distance between Point 1 and Point 2.




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The measurement result is displayed and “2 —“ is displayed in flashes.


Result display

“3—“ is displayed in flashes.

Press this button to make the constant measurement.


Stop the constant measurement. The height or width between Point 1 to Point 2

can be displayed.

5.2.3.10 User Information

1. Measurement range

Usually, the laser is used for tracing outdoors in the day, and the target should be

in the shadow.

2. Increase of measurement range:

The measurement range may increase a little at night or dusk or when the target

is in a shadow.

3. Shortening of the measurement range

The rough green or blue surface may shorten the measurement range (Both

vegetation and trees can have the same effect).

5.2.3.11 Rough Surface

Upon measuring a rough surface, such as a cement wall, the mean value of the light

point is to be displayed.

To avoid taking the value of brick joint upon rough measurement, use the target board,

such as the 3 M “POST-IT”, or cardboard.


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5.2.3.12 Measurement of Transparent Surface

To avoid any error in measurement, do not make measurement on the colorless liquid

(water) or glass (dust-free) surface.

If traversing a piece of glass or there are many targets in one place, the vacancy

measurement will occur.

5.2.3.13 Measurement of Humid, Smooth or High-Luste r Surface

1. If the aiming angle is very small, the laser will be reflected, which make

DISTO unable to receive the weakened signal (No. 255 error will appear in the

display;

2. In the case of aiming in a right angle, the laser reflection is too strong (No. 256

error will appear in the display);

Measurement of inclined or round plane

When the target is so big that the laser point can be projected on it, the

measurement can be made.

Bare-handed aiming (about 20 ~ 40 m)

Use a chopping block, 563875 (DIN C6) or 723885 (DINA4)

—30 m from the white side:

—30 m from the brown side:

5.2.3.14 Field Measurement

DISTO CLASS 5 has an integrated telescope collimator with twifold magnification.

Upon measuring in a distance of more than 25 m from a target, the laser point is

displayed in the center of the collimator, and within 25 m, it is displayed on the edge.

Fig. 5.2-12 Telescope View


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5.2.4 Technical Parameters

Technical ParameterMeasurement precision (trip measurement

standard deviation)

Minimum display unit

Range measurement

Measurement time Measurement/tracking

Φ Facula diameter of the laser beam (distance)

Integrated diopter

Illumination

Multi-row display

Multifunctional base

Delay measurement

Calculator

Tracking measurement

Constant

Maximum/minimum tracking measurement

Pythagorus' theorem

Memory (storage)

Battery, model AA, 2x1.5V

Dust-proof, splashing-proof

Dimension and weight

Measurement precision of level tester

Standard: +/- 3 mm/Max.: +/- 5 mm

1 mm

0.2 m to 200 m * **

5… about 4 s /0.16. about… 1 s

6/30/60 mm(10/50/100 m)

10 values

15 values

To the 10,000 th measurement (onlylimited to the alkaline battery!)

IP54 acc. IEC529: splashing-proof, dust-proof

172 x 73 x 45 mm, 335 g

1*

Temperature range

StorageUse

Fig. 5.2-13 Technical Parameters

The right to change the technical data is reserved.

1. The minimum display unit is 1 cm for the measurement range of 100 m.

2. The long-distance measurement of +/—5ppm (+ —0.5mm/100m) includes the

close-quarters error.


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5.2.5 Signal

Error signal

Such a signal is displayed on the screen.

Signal

203

204

252

253

Cause

Dimension error uponusing Pythagorus theorem

Calculation error

Too high temperature,exceeding 50o (Measurement)

Too low temperature,exceeding -10 o (Measurement)

Solution

To measure in thecorrect order

To operate again

To cool down the instrument

To warm up the instrument

Fig. 5.2-14 Schematic Diagram 1 of Error Signal

Signal

255

256

257

260

Cause

The received signal is too weak andthe measurement distance is too

large, distance < 200 m

The received signal is toostrong

Measurement error, too brightbackground

Laser interruption

Other signals

Solution

To use a sight vane, measurementtime > 10 s

To use a sight vane (thecorrect side)

To use a sight vane

To operate again

Contact the servicing department

Fig. 5.2-15 Schematic Diagram 2 of Error Signal

If this signal appears for many times in measurement, switch on/off the instrument.

If the error signal still appears, contact the repair personnel.

5.2.6 Maintenance

Protect the optical part of the instrument just like eyeglass, camera and telescope.


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5.3 Use and Selection of Digital Camera

5.3.1 Brief Introduction

In the site survey, the digital camera should be applied. It is used for photographing the

environment of the planned area or around the site as well as the roof of a site.

This specification is applied in the phase of requirement analysis, electrical

measurement and site survey of network planning, as well as in the phase of network

optimization.

5.3.2 Specifications

Digital camera is an important auxiliary tool for information recording, the pictures

taken is an important means of propagation model for the project manager to judge the

necessity of site survey and the applicability of a planned area environment. To ensure

the correctness and comprehensiveness of the information recorded in the digital

photos, specify the following requirements on the use of the digital camera.

5.3.2.1 Preparations before Departure

1. Flash memory capacity: Make sure to meet the need of photographing. If it is

too small, it should be cleared.

2. Battery capacity: Make sure that the rechargeable batteries of the camera are full.

For the camera using No. 5 battery, a set of spare batteries should be available,

especially for the survey in the remote areas.

3. You’d better take two pictures for a try to ensure that your camera can normally

work. You should try the data line or PC software in your camera upon receiving

it.

5.3.2.2 Camera Setting

1. Setting the quality of pictures: The survey personnel can select an appropriate

picture quality based on the survey job on that day, considering the quantity of

40 ~ 80 pictures per day, the capacity of the flash memory and the quality of

pictures. The picture quality of 800 x 600 is recommended.

2. In the setting of a camera, you should pay attention to the display of date and

time, for the convenience of information management later on.

3. Set the mode of distant view and improve the sharpness of the pictures taken


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around the site environment.

4. The camera has the function of adjusting parameters such as shutter, depth of

field and sensitivity. It is required to use auto mode so as to avoid differences in

picture quality due to personal reasons.

5.3.2.3 Photographing Requirements

Upon photographing the environment around a site, you should adjust the focus of your

camera to minimum, to ensure the maximization of view-finding range. Do not adjust

the focus with the digital function.

Upon photographing the environment around a site, the sky should occupy 1/4 ~ 1/5 of

the whole picture in the view-finder window. Note: Keep the level of the horizon in the

picture.

Note: Do not shake upon photographing, especially in darkness or in the case of

long-time exposure.

Upon taking the picture of the environment around a site, you should do it starting

from the right north and take each in every 45°clockwise. Upon using a compass to

determine the direction of photographing, it is recommended to determine a reference

object with the compass, and use the camera for photographing based on the reference

object, to ensure the correctness of the photographing direction. The picture of the

environment around a site must be taken levelly, and photographing in vertical position

is not allowed; for the case of irregular buildings, it is recommended to draw a

coordinate axis in the position for photographing based on the direction pointed out by

the compass, mark the direction in which the photographing is done, and take pictures

in the specified direction, but the position for photographing is allowed not to be any

point on the coordinate axis.

Upon photographing the environment of a site, it is recommended that you lean against

the parapet wall when the floor is too large, to avoid the sheltering of the floor; when

the floor is small, it is recommended to take pictures at the highest point of the building

under the pre-condition of ensured safety; when there is an iron tower, it is required to

ensure the photographing point is over 10 m higher than the surrounding environment.

Upon photographing the floor, it is required to include an area of more than 90% of the

whole floor, and the approximate position of the planned antenna must be included in

the picture. If the position of co-site G-network antenna and cabling rack must also be


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in the picture. To meet the requirements, multiple pictures can be taken, and it should

be noted in the name that the part of the roof that the picture shows.

The picture of the equipment room should be taken at the door; in the picture of the

appearance of a building in the site to be selected, the whole building should be taken

into picture.

There should be no survey personnel or customer personnel in the pictures taken.

After taking pictures for each site, you should review all the pictures of the site with

your camera with LCD, to ensure they have been correctly taken; you should take

pictures with doubled care due to no review function available to the ZIGUANG

camera. You’d better import the pictures into your PC and check it immediately after

taking the pictures of a site; for those pictures that have not been properly taken, you

should do it again.

Caution:

You should use the exposure compensation function of the camera with great care. If it

is dark or bright, you should review your pictures at once.

In the darkness, you can adjust the sharpness of your camera.

5.3.2.4 Contents of Photographing

1. Eight pictures for the ambient environment, starting from the right north, each

picture taken in the angle of 45o

2. Multiple pictures of ceiling, taken separately based on the size of the roof.

3. One picture for the appearance of a building in the site to be selected.

5.3.2.5 Naming Rule

The pictures should be named as ruled below:

XX (Name of a service area or name of a city/county) XX (site name) North (or

northeast, east, east of the roof)

5.4 Compass Use Specifications

5.4.1 Structure of a Compass

Generally, a compass is housed in a round box. It comprises two parts, one for the


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compass on which there are a pointer and a dial, and the other part is a scale and an

idler wheel.

The appearance of the compass is shown in the figure below:

Fig. 5.4-1 Appearance of a Compass

5.4.2 Basic Operations

5.4.2.1 Determining the North Pointer in a Compass

Open a compass and place it flatly. The zero line of the compass must be in line with

the pointer with a dot, as shown in the red circle 1 in Figure 1, and the pointer must

direct to north (Magnetic North).

Note: Some compasses have their white needle pointing to north while some others

have their black needle pointing to north. The end of the pointer with a dot should be

the reference.

5.4.2.2 Determining the Direction Angle of the Sect or Antenna

In the first place, you should determine the orientation of the sector, and point the north

direction on the compass dial to the determined direction. In this case, the read of the

pointer directing to North is the direction angle of the antenna. as shown in the Fig.

5.4-2:

Antenna

North

Zeroline

AntennaAzimuth

South

Fig. 5.4-2 Direction angle of the Antenna


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5.4.2.3 Measuring the Direction Angle of the Instal led Antenna

Way 1: Similar to the above. Use the zero line of the compass dial to aim at the central

axis of the back(or front) plane of the antenna. Apply the central axis of the antenna to

make the notch (as shown in red circle 1 in Figure 1) of the compass coincide with its

notch (as shown in red circle 2 in Figure 1), to ensure that the pointer is vertical to the

plane of the antenna. The read of the north pointer is the direction angle of the antenna.

If aiming at the central axis of the back(or front) plane of the antenna, 180o should be

reduced to get the direction angle of antenna. as shown in Fig. 5.4-3:

entral axle lineof antenna

Zeroline

NorthInclinationbetween the

central axle lineof the antennaand the north

direction

South

Fig. 5.4-3 Measurement of Antenna Azimuth

Way 2: To measure or locate the azimuth of the antenna, you can measure the azimuth

of the base line of the antenna back plane, and there is only a difference of 90o between

both of them, in this way, the inconvenience in some special cases can be avoided.

Suppose a person faces the right front of an antenna, he can measure the azimuth to the

left of the base line of the antenna back plane, so the antenna azimuth equals the

azimuth of the base line of the antenna back plane plus or minus 90o.

Here is the description with the azimuth to the left of the base line of the antenna back

plane, as shown in Fig. 5.4-4. Then, the north seeking degree, A, read by the compass

is the azimuth of left direction for the base line of the antenna back plane, and the

antenna azimuth is A minus 90o. Keep the zero line of the compass consistent with the

base line of the antenna back plane (opposite direction is also allowed, but the formula

should depend upon actual situations.)


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Northdegree

SouthZeroline

Baseline ofantenna

back plane

The pointeddirection of

antenna

Left directionof the baselineof the antenna

back plane

Northdegree

South Zeroline

Fig. 5.4-4 Measurement of Antenna Azimuth

5.4.2.4 Measuring the Downtilt Angle of the Install ed Antenna

Open the compass, place its straight side on the back plane of the installed antenna, and

adjust the gradienter with the manipulator behind the compass until the gradienter is in

the level status. In this case, the scale degree (internal dial) indicated by the white dot

beside the gradienter is the downtilt angle of the antenna.

5.4.3 Precautions

Do not use a compass around the strong magnetic field, and do not put a compass on a

metal platform (including an iron tower) or near a metal target, because these factors

may affect the positioning precision of the compass.

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6 The Propagation model test and correction

6.1 Propagation Model Test Operation Process

Follow this process during a propagation model test:

Start the test

Formulate working plan for propagation model test

Group leader

Submit data and export testing reports

Group leader

Prepare and check testing equipment

Coordinator and testing personnel

Exploration and selection of testing sites

Explorationing engineer

Preparation of testing environment, data

collection and processingTesting engineer

Selection and preparation of testing

routesExplorationing engineer

Client affirmance

Data accords with revision requirements

Test finishes

Propose communication for exact requirements

Coordinator

Output: A Plan of Propagation Model Test in XX Service Area

Output: Exploration Report of Propagation Model in XX Service

Area

Output: Route Selection Report of Propagation Model in XX Service

Area

Input: Exploration Report of Propagation Model in XX Service Area and the Route Selection Report of

Propagation Model in XX Service Area; Output: testing data of propagation model in XX service area

Output: Plan of Propagation Model Test in XX Service Area，the Exploration Report of

Propagation Model in XX Service Area, the Route Selection Report of Propagation Model in

XX Service Area and the testing data of propagation model in XX service area

Ｙ

Ｙ

N

N


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6.2 Test Procedures

This section introduces specific procedures and main working operations for

implementing a propagation model test.

6.2.1 Equipment Preparation

Equipment mentioned in the following table should be prepared for this test:

Name Quantity Description

Pilot transmitter 1 Transmit frequency and power-adjustable pilot signals

Line tester 1 Include receiving antenna, data line, GPS antenna and hardware dongle

Lap-top 11 Installed test software, storage battery and power cable

Vehicle mounted power supply 1 Include cigarette lighter connection line, inverter and power connector board

Tripod 1 Fixed antenna

Omni antenna 1 Propagate pilot signals with the frequency band corresponding to the

transmitter

Feeder and jumper 1 Connect pilot transmitter and antenna with connectors protected well

Power cable unit 1 Used for providing power supply for the pilot transmitter, including

connectors and connector board with its length more than 50m

Site exploration equipment 1 Explore the testing site, including digital cameras, compass, ranging tester or

elevation tester, GPS, rechargeable batteries and chargers

Map 1 Marked with detailed routes

Adjustable wrench 2 Fasten the antenna

Rope 1 Longer than 30m

Common tools 1 Include pincers, screwdrivers (both cross and straight), glove, socket

conversion connector and tape

Remarks: Being expensive, precious and easy to be damaged, the pilot transmitter and

line tester are expected to be carried by testing personnel their own instead of being

transported because of too much luggage for out-site tests.

6.2.2 Testing Site Selection

6.2.2.1 Selection Procedures

1. Testing area confirmation

Areas within the planned region or required by the client are expected.

2. Testing area division

First, divide the testing area into three parts based on their terrain features: Open

lawn, hill and mountainous region. Second step is to divide it according to its


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environment into large and dense city, medium-sized city, town and village.

At last according to proportions of various field features, it can be further

divided into: Dense city, usual city, countryside and village.

3. Primary decision

Remark the testing sites on the map.

4. Site exploration

Explore the expected testing sites and record their environment features.

5. Site selection

According to the records, find out the testing site that meets requirements based

on the site selection principles.

6. Selection report export

According to the site information, export a report based on the requirements

mentioned on the Template of Propagation Model Testing Site Exploration

Report in XX Service Area.

6.2.2.2 Site Selection Principles

1. No obvious obstacles exist around the site.

2. The antenna position in the site should have the same height as that installed for

the model in this site. The site should be a little higher than buildings around.

The antenna installed in testing sites in dense cities and areas should be 10m

higher than average buildings around, the antenna in usual cities 15m higher,

and the antenna in countryside or village 15m to 25m higher.

3. Select two to four testing sites in further divided testing area and eliminate

possible position influence using testing data get from several sites after data

combination and model adjustment. In this case, terrain environment of the

representative model to be adjusted should be consistent with that of other

testing sites. At least four sites should be taken as testing sites in dense cities and

areas, at least three in usual cities, two in courtsides, and 1 in villages.

4. A model token can be used instead of propagation model in some small cities

without dividing them into dense, usual areas and countryside. Therefore, a

representative site in the center of the city can be selected for testing. As for


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medium-sized cities, two tokens can be considered, dense area and countryside,

and two representative sites are expected for testing.

5. In some offices in small cities but dense areas, the client may require a certain

number of sites to be taken for a test, for example 3 sites with each being

completely tested. However possibly only one site is enough in the whole city

for the test. In such a case, the 3 sites can have repeated routes but cannot be

divided into different areas with different routes, thus avoiding inadequate site

data and poor propagation model get from data combination and model

adjustment.

6. There should be various field features around testing sites and enough roads to

reach there.

7. The building of the testing site should be of middle size to avoid adding antenna

height and influencing transmission of testing signals caused by walls,

especially parapet walls.

6.2.2.3 Site Environment Information Records

1. Measure with GPS the attitude/latitude of the testing site and places installing

the testing antenna for sites with large-scale floor. The attitude/latitude data

should be in decimal notation accurate to 5 decimal digits.

2. Measure height of the testing antenna (relative height from the middle part of

the antenna to the ground), using the ranging tester or elevation tester.

3. Take pictures in the following eight directions: North, north east, south ease,

south, south west, west, and north west with a digital camera and a compass.

4. Take a picture of the floor with the testing antenna.

5. Name all the pictures with the same module as XX (service area) XX (site name)

XX (direction or position, such as north or floor).

6. Give descriptions about features around. When there are obstacles around,

height of the obstacle and distance between it and the antenna should be

included in the description.

7. According to the site information, export a report based on the requirements

mentioned on the Template of Propagation Model Testing Site Exploration

Report in XX Service Area, referring to Appendix B.


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6.2.3 Testing Route Selection

6.2.3.1 Selection Procedure

1. Get a general knowledge about the geography environment.

First, you need to have a general knowledge about the geography environment

by buying a detailed map with main roads marked on or getting related

geography and humanistic knowledge with the help of local residents.

2. Work out the testing routes

Work out the testing routes according to route selection principles and terrain

and roads around the testing site. An on-site review of the testing route is

recommended before implementing the test.

3. Make a chart of the testing route

Mark the material routes on the map with a pen or on the electronic map and

print it out.

If possible, you can add the map in the Agilent ranging tester software to carry

out real time supervision. Refer to the Appendix E for the usage of the software

mentioned.

4. Export route selection report

Export a report based on the requirements mentioned on the Template of

Propagation Model Testing Site Rout Selection Report in XX Service Area.

6.2.3.2 Route Selection Principles

1. The following routes should be considered: Routs in four directions with

different distances, all the available routes within various field features, main

routes and alleys with the width less than 3m.

2. A route shall not be tested repeatedly. The first data can be used. In case of

parking (due to red light for example), no data should be recorded (pause the

testing software in case a software is used).

3. The testing radius should be as large as possible to ensure the weakest signals to

be received by the receiver under –120dBm. Adjust the testing routes according

to the signal receiving condition. However for some medium-sized cities, you do

not need to go further to distant village even if the signal at the edge of the city


112112112112

is above –120dBm.

4. The vehicle shall move at the moderate speed slower than 40km/h in the test.

5. Routes with lakes and rivers if there are lakes and rivers in the city shall be

avoided.

6. In case of a hill in the city, you can check signals at the hill back to get

diffractive factors based on signal attenuation. Attention: Do not check signals

of the hill at the same side as the base station. In such a case, signals will be

stronger with height increase because that there are fewer obstacles in high

places. Thus, the curve get in this situation will show that farther distance leads

in better signals. If the model is adjusted according to such a curve, the standard

offset will increase.

7. Recommended route selection methods: First check the west-east direction and

then the south-north one to work out a route network as shown in Fig. 6.2-1 and

Fig. 6.2-2, Fig. 6.2-3 shows the exact route map.

start

end

Fig. 6.2-1 Route map 1


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Fig. 6.2-2 Route map 2

Fig. 6.2-3 Actual route map

8. Sampling routes shall be checked: Sampling routes should be equally distributed

in four directions and surround the testing site as the axis. Two to three sets, at

least two sets, of sampling data should be carried out in each direction, avoiding

too many or too few sampling routes in a direction.

9. As for test of sites with a great testing distance, it is difficult to cover all the

areas. Therefore, you can implement the test in areas under the expected to be

covered direction until receiving signals under -120dBm. If possible, you can

choose a parallel route to return so as to get two sets of sampling data for


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super-distant model research.

6.2.4 Test Environment Preparations

When conducting the propagation model test, test environment is composed of

equipment like radiation, receiver, antenna, as shown in the following figure:

Lap-top background

Transmitter

Receiver

(UE)

Antenna

6.2.4.1 Preparations at Transmission End

1. The omni-antenna is mounted on the roof or a building or a tower. Make sure

that the test point in the first Fresnel zone set up with the antenna should be of

no obstacles. When installing the omni-antenna at the top of the building, the

position of the antenna should be as close to the building edge as possible,

avoiding that the wave radiation may be hindered by the edge of the building in

all directions. If the antenna has to be installed away from the edge of the

building, it must be installed high above the building floor. If it is installed on

the tower, it must be 1 meter higher than the highest point of the tower to avoid

the effect to the signals transmission from the tower itself.

2. The antenna and the transmitter must be connected with jumper connectors

tightly (make sure that fastened nuts cannot be screwed by hand), and any part

of the jumpers should not be twined. In rainy days, feeder heads must be

water-proof. Protect the connectors with a protective cap after using the feeder

cable and the antenna to avoid damage from tossing on the way.

3. Check before the startup of the pilot transmitter if ports of antenna are connected

well with the antenna or if it is big loaded (more than 50W), otherwise amplifier


115115115115

will alarm or be damaged because of the self-activation caused by mismatch.

4. After the startup, check whether the fan begins to work at the back of the

machine; if it fails to start working after long time, there will be a temperature

alarm caused by excessively high temperature (over 70°).

5. Connect the pilot transmitter with the background of the lap-top by the network

cable. Startup the background of the pilot transmitter on the lap-top.

6. The pilot transmitter is connected with 220 V AC power supply or 24V DC

power supply, Switch to the connected power supply and the system powers on.

Alarm indication on the background interface of the transmitter and the LED

turn from red to green. It shows that it has been connected with the background

and the machine starts to work, as shown in the following figure:

7. The frequency of the pilot transmitter must be configured close to the frequency

in the real system. A clean frequency can be selected through the receiver. In the

selection of “Frequency Configuration”, input the needed frequency and click

“Frequency” to make it work.

8. Set the attenuation to adjust the output transmitting power of the pilot transmitter.

In the selection of “Frequency Configuration”, input the needed frequency and

click to enable it. When the attenuation is set as 0dB, the maximum output

power of the pilot transmitter is 40dBm (10 W); when the attenuation is set as

7dB, the output power of it is 33dBm (2W).When conducting a propagation


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model test, usually the output power of transmission is set as 10 W.

Frequency Configuration

Attenuation Configuration

9. You should record data such as transmission power, frequency and antenna gain

in the following table as carrying out a test.

Parameter Value

Scramble

Testing frequency

Transmission power of pilot channels

Antenna manufacturer and model

Antenna main gain

Antenna working frequency range

Antenna height

6.2.4.2 Preparations at Receiving End and Data Reco rd

1) 1. Set the receiving antenna of the receiver and GPS antenna on the middle part of

the top of the car.

2) 2. Connect the lap-top and the receiver with the data line (COM1 interface of usual

lap-top for connection the data line), connect the antenna of the receiver and GPS

antenna with the receiver, provide power supply to the lap-top and receiver using a

cigarette lighter and inverter. Storage batteries and UPS can also be used for power

supply, referring to the Appendix D for usage attention of storage batteries.


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3. Start the Agilent E6474A software, open System Setup from File > New, and

right click the COM port connected with the receiver, in usual case the receiver

and the COM1 port of the lap-top are connected through a data line. Select

Manual Refresh from the pop-up menu and Agilent Receiver in the Equipment

List . Then you need to wait for about two to three minutes for the software to

identify the receiver.

Equipment configuration

Right click Com Port to search the equipment


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A dialog box will pop up after the software finds a receiver. Click Yes for

acknowledgement. You can click Detail to view the detailed information of the

hardware equipment at the COM port where E6455C stands for the receiver and

TSIP Navigator for GPS equipment in the receiver.

3. Make sure that you select the TSIP Navigator because it is not selected by

default after the software identifies the receiver, so you need to select it.

4. Edit equipment properties. Select the receiver, E6544C, and right click it to enter

the Properties page. Add the items to be tested in the Choose Measurement

tabbed page: CW/Channel Power and W-CDMA/UMTS Scrambling Code

Analyzer. You can carry out the frequency cleansing test before the normal test

using the Spectrum Analyzer, referring to the Appendix G.


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Set the Measurement Type to Channel Power List in the CW/Channel Power

page.

Set other parameters as shown in the figure.

In the W-CDMA/UMTS Scrambling Code Analyzer page, select User List as

the measurement mode and carrier wave frequency as the testing frequency of

the propagation model. Add pilot signals scramble in the User List, which is

fixed to 400 in usual pilot transmitter. Set Timeslots to 5 (you can set it to 5 first

and then deselect Primary SCH Scan and Top N in the Measurement Type).

Set the sampling interval mode to Time (0s).


120120120120

5. Select File > Save As after searching and configuring the equipment to save the

configuration files in *.spf format. In this way this configuration file can be

opened directly without reconfiguration for the next test.

6. Data recording. Click the yellow button on the toolbar to enter the real-time

display mode where no data record is implemented. Click the green button to

enter the file dialog box, and enter the data position and file name to record the

data. In case of parking during a test, click the Pause key on the toolbar to pause

data recording. Click Stop key on the toolbar to finish data recording and save

the data file after a test ends.


121121121121

Pause the test

Data collection mode

Real-time display mode

Stop sampling

6.2.5 Test Result Processing

6.2.5.1 Test Database Exporting

1. Click Tools > Export Wizard on the menu and select the test data files to be

exported (in the format of *.sd5).

2. To create a new template for export. Select New export plan. Click Next to get


122122122122

the dialog of Select Columns for Export and Select Position (Longitude and

Latitude) in Optional Columns checkbox.

On the left of the dialog, select Receiver > W-CDMA Scrambling Code List >

SC Agg Ec and add to the right column. For the post model correction,

exporting in the Selected Columns needs to be in the order of Longitude,

Latitude and SC Agg Ec.

3. Click Next, there is the Define Selected Column Properties dialog box.


123123123123

4. As the prompt in the menu, find the page shown below and select SC Agg Ec in

the dropdown.

5. Select Apply Binning … and click Next.


124124124124

6. Configure the parameter as shown in the following figure (Bin as 6m)

7. Click Next. The Define Export dialog box pops up. Select Tab-Delimited in

Output File and Signed Decimal Degrees in Lat/Lon.


125125125125

8. Click Next. Click Save to save the template to export for later use. Select the

device from which the data will be exported as shown in the following figure

(tick in the checkbox)

9. Click Export to Files and input the names of the data for export (generally

including the names of the test site and the test time). The format of the exported

file is as shown in the follow figure (after combination):


126126126126

6.2.5.2 On-site data test

After the test of the propagation model, for the validity and effectiveness of the

preliminary on-site data testing, to avoid being not ideal when turn in the test data to

the staff who do the correction, to avoid the waste of the labor and materials causing

the affects upon the overall quality of the plan and design, the test staff need verify the

test data on site with the data testing tools to see if it needs to be re-test.

6.2.5.3 Export of the test report

After the test, export the test report according to the Report Template for the

Propagation Model Test. After exporting the .txt files, the original .sd5 data files,

propagation model test report, test site information and photos of the surroundings,

routing of the test site, turn them in to the emulation team to make corrections to the

propagation model.

6.3 WCDMA Propagation model tuning

Propagation model tuning plays a very important role in network planning. Its accuracy

directly affects the wireless network planning scale, coverage prediction accuracy, and

base station (BS) deployment. This document describes how to make operations such

as data filtering based on effective data provided by test personnel to make an

acceptable propagation model.

6.3.1 Inputs for Propagation model tuning

The following are input parameters for propagation model tuning:


127127127127

Test data

The foundation of propagation model tuning is the multitude of effective test data,

related parameters of the transmit and receive systems, and test photos and problem

description materials. For detailed test data needed for propagation model tuning, refer

to the test data part of the propagation model tuning test specifications.

Electronic map

The electronic map, also called digital map, describes the geographical information of

the area in a digital form. It is a necessity for propagation model tuning. It has two key

parameters: earth model and projection mode. In the mobile communication field, the

most used electronic map format is Planet/EET (proposed by MSI/ ERICSSON), which

supports information included in electronic maps of various earth models and

projection modes. The electronic map covers geographical information such as

hypsography, height, clutters, vectors, and buildings that affect propagation of electric

waves. These are all important basic data for propagation model tuning.

Accuracy of the electronic map depends on the propagation model, the planning

precision, and application environment. Generally, it is of 5 m precision for micro

cellular environments in densely populated cities, 20 m for general cities, 50 m for

suburbs, and 100 m for rural areas. To use an electronic map, you also need to learn its

update time.

Propagation model tuning Software

Propagation model tuning is an important part of network planning. Generally, all

network planning software, including AIRCOM and PLANET, can adjust the

propagation model. Now, we use AIRCOM.

6.3.2 WCDMA Propagation model tuning Process

Fig. 6.3-1 is the flow chart of propagation model tuning.


128128128128

Fig. 6.3-1 WCDMA Propagation model tuning Flow Chart

The following describes each link in the flow chart.

6.3.3 Preprocessing Test Data

6.3.3.1 Filtering Test Data

A multitude of effective test data are the foundation of propagation model tuning.


129129129129

Therefore, it is a must to filter the test data submitted by test personnel and use really

effective test data that reflect propagation characteristics to adjust the propagation

model to make the model well reflect the signals of the covered area. The following

data should be filtered out:

1. Data of remote points

When the receiver is distant away from the transmitter, the signal received is too

weak and thus usually the measured value is inaccurate because of the receiver

sensitivity. In addition, for the CW test signal the back noise accounts for a

higher proportion in signals received at remote ends, posing another

disadvantage for model tuning. For these reasons, data of remote test points

must be removed. For pilot frequencies, points whose CPICH Ec/Io is less than

-15 dB or whose CPICH Ec is less than –110 dBm must be removed. For CW

signals, points whose Io is less than –95 dBm must be removed. The specific

remote threshold value depends on the coverage. When calibrating a macro

model, a distance filter must be used.

2. Data of close points

As the power of signals near the BS is mainly affected by buildings and streets

near the BS because of influence of the antenna height pattern, test data of

points near the BS cannot be used to adjust the propagation model. When

calibrating a macro model, a distance filter must be used.

C.Y.Lee believes that when d<=4h1h2/λ(where, h1 and h2 are heights of the BS

antenna and the mobile station (MS) antenna and λ is the wavelength), it is close

distance. For example, if h1=30m, h2=1.5m, and f=2140 MHz, all points whose

d is less than 1284 m.

You can use filters in the network planning software to filter test data of remote

and close points.

3. “Waveguide effects” (or “street effects”)

An electric wave propagation test is generally conducted on a street. For a street,

there are “waveguide effects”: when the propagation direction of the electric

wave from the signal source has a small angle with the street direction of the test

point, the signal received will be significantly stronger than usual and make the

signal in parallel with the propagation direction about 10 dB stronger than that

vertical with the propagation direction.


130130130130

As the purpose of a propagation model is not just to predict path loss but to

reflect the propagation condition of the whole covered area, waveguide effects

and other road-related factors must be removed. Otherwise, the adjusted

propagation model may be too big or small at large.

4. Other data points that are obviously abnormal

6.3.3.2 Adjusting Test Data

1. Adjusting GPS data

As there is something inaccurate with the GPS positioning, longitudinal and

latitudinal information of the test data must be adjusted to eliminate

geographical difference and thus make the test data full agree with the test route.

2. Merging test data

For a typical artificial environment, generally the test is conducted at more than

one test point. To make full use of the great deal of effective data got from the

multi-point test, test data of different sites must be effective merged. However,

because of differences between different sites (mainly because of the different

antenna effective heights), in the merger data of different sites must be adjusted

based on a certain reference. This processing only applies to propagation model

tuning through curve fitting. For the specific process, see the section about

propagation model tuning methods.

6.3.3.3 Selecting Data for Propagation Model Tuning

If the CW transmitter is used, use the broadband gross power collected by the received,

RSSI (Io) to adjust the propagation model. If the transmitter is a pilot frequency one,

you can use CPICH Ec, CPICH Ag.Ec, or RSSI (Io) to adjust the propagation model.

The following describes the advantages and disadvantages of these three kinds of data.

CPICH Ag.Ec is the result of rake combination of power of all paths after the effects of

multiple paths on received signal are considered. CPICH Ec is the power value of a

single path of the multiple paths. As the WCDMA system adopts the rake receiver

technology, CPICH Ag.Ec is more suitable for propagation model tuning than CPICH

Ec.

RSSI (Io) is the power of the whole receiving bandwidth. It consists of interference

signals and back noise as well as useful signals. If the test environment is unclean, the


131131131131

proportion of interference in RSSI will increase and thus RSSI cannot effectively

reflect the strength of useful signals received. However, when the frequency is well

cleaned, appropriate equilibration can effectively eliminate the effect of fast fading

because RSSI (Io) has a high collection rate. Compared with RSSI, the CPICH Ag.Ec

received by the receiver is pure useful signals. Although using it to adjust the model

can accurately calculate out the propagation loss, due to the data collection and

software processing rates it cannot effective filter out effects of fast fading. Therefore,

it is better to use RSSI (Io) to adjust the model when the test environment is clean and

to use CPICH Ag.Ec if the vehicle advances at a slow speed or there is only small fast

fading with the signal.

6.3.3.4 Format of Model Tuning Data File

Data used in propagation model tuning are only the longitudinal and latitudinal

information got in drive test and the signal strength of the data items selected. There

are two data files used in propagation model tuning, file header *.hd and file body *.dat.

Their formats are as follows:

PHO1.hd PHO1.dat

The file header records the BS information and test information of the propagation

model test, including the test data file body used, longitude and latitude of the BS,

antenna height, obliquity, deflection, antenna type, BS equivalent launched power EiRP,

feeder type, length, loss, and transmit frequency. The file body includes test data, that

is, the longitude, latitude, and signal strength. Its first column records the longitude,

second column the latitude, and the third the signal strength, with different columns

separated with a tab.

6.3.4 Selecting Propagation model

For 800 MHz electric waves, a frequently used model is Hata, which is got through

formula fitting based on Okumura test data.

As using the Okumura model involves finding its various curves, this model is not

suitable for computer prediction. Based on the mid-value signal strength prediction

curve of Okumura and through curve fitting, Hata proposed an empirical formula for

propagation loss, the Okumura-Hata model.


132132132132

For simplification purpose, Hata made the following three hypotheses for the model:

1) The model is based on propagation loss between two omni antennae.

2) The terrain is flat rather than irregular.

3) Use the propagation loss formula for urban areas. For other areas, adjust the data

with a tuning formula.

Applicable conditions:

f is 150–1500 MHz.

bh, effective height of the BS antenna, is 30–200 m.

mh, height of the MS antenna, is 1–10 m.

The communication distance is 1–35 km.

The propagation loss formula is as follows:

γ))(lglg55.69.44()(lg82.13lg16.2655.69 dhhahfL bmbbCity −+−−+=

Description of the formula:

The unit of d is km and that of f is MHz.

bCityL is the mid-value of basic propagation loss in urban areas.

hb, and hm are effective heights of the BS and MS antennae. They are counted in

m.

The effective height of the BS antenna is calculated as follows: Suppose that the BS antenna is sh from the floor, the altitude of the BS floor is gh , the

MS antenna is mh from the floor and the altitude of the MS is mgh , then the

effective height of the BS antenna, hb, is the value of ( sh + gh - mgh ) and that of

the MS antenna is mh .

(Note: There is many a method to calculate the effective height of the BS

antenna, for example, the average of the floor altitudes within 5 to 10 km from

the BS and the landform fit curve of the floor altitudes within 5 to 10 km from

the BS. The calculation method depends on the propagation model used and the

calculation precision required.

MS antenna height tuning factor:


133133133133

=<<−

<<−

−−−

=

mh

MHzfh

MHzfh

fhf

ha

m

m

m

m

m

5.10

city Large150040097.4)75.11(lg2.3

2001501.1)54.1(lg29.8

city size-smallor -Medium)8.0lg56.1()7.0lg1.1(

)(2

2

Long-haul propagation tuning factor:

>×+×++≤

= −− 20)20

)(lg1007.11087.114.0(1

2018.034 d

dhf

d

bγ

Tuning factors:

streetK —street tuning factor

Generally, only the tuning curve of losses in parallel with or vertical to the propagation

direction is given. For convenience of calculation, the following gives the fit formula

for arbitrary angles.

Assume that the angle between the propagation direction and the street is θ, then:

<+−−

≤−−+−−=1)cos6.7sin9.5(

1cos)lg6

106.7(sin)lg

6

119.5(

d

dddK street

θθθθ

As generally the street effect disappears beyond 8–10 km, you only need to consider

the street effect of within 10 km.

Kmr—suburb tuning factor

)4.5))28/(lg(2( 2 +−= fKmr

Qo—open area tuning factor

)94.40lg33.18][lg78.4( 2 +−−= ffQo

Qr—quasi-open area tuning factor

5.50 += QQr

uR —rural area tuning factor

17.23lg17.9)(lg39.2)28

(lg 22 −+−−= fff

Ru

Kh—upland area tuning factor


134134134134

≤≥∆+∆+∆+−−>≥∆−−∆+∆+−−

<∆=

1,15)2.7)lg96.6024.07.5(

1,15)2.7lg5.9()lg96.6024.07.5(

150

1

11

hhhh

hhhhh

h

K h

⊿h—land undulation height, as shown in the following figure. It is the difference

between 10% and 90% of the undulation height of the area 10 km from the MS toward

the BS (if the area is less than 10 km, use the actual distance). This method applies to

the condition that the land undulates multiple times (>3).

⊿h 10%

90%

1h = mgh -⊿h/8- minh . minh . It is the minimum height of the calculation section ⊿h.

Ksp—slope tuning factor

1)

2)

3)

Base station

h1

h2

H +θm

d3

d2 d

Mobile station

d2

d1

(a) Positive slope+θm

d1

h1

H

1) 2)

3)

d2 d3

d

h2

(b) Negative slope-θm

-θm

A slope landform may produce secondary floor reflections. When d2>d1, both the

positive and negative slopes shown in the figure may produce secondary reflections.


135135135135

The slope tuning factor can be roughly calculated as follows:

mmmsp ddK θθθ 44.0002.0008.0 2 +−=

mθ is calculated in mini radian and d in km.

mθ is the mean obliquity of 1 km before and after the MS at the section on the straight

line between the MS and the BS got through least square.

Kim—isolated hill tuning factor

This factor is calculated using shade diffraction. This calculation method involve a big

volume of calculation work but is accurate.

The following figure shows this method:

hph1

r1

r2

First, calculate out the four parameters of each single shade, that is, 1r , 2r , ph , and

working wavelength λ .

Use these four parameters to calculate parameter v:

)11

(2

21 rrhv p +=

λ

Calculate the diffraction loss:

−<=−>−++−+=

7.00

7.0)1.01)1.0(lg(209.6 2

v

vvvK im

Ks—Sea (lake) mixed path tuning factor

When the propagation path involves an water area, there are two different situations to

consider, as shown in the following figure:

Base station

Mobile station

ds d

Base station

Mobile station

d ds

(a) Base station near land (b) Base station near waters


136136136136

Define the tuning factor to:

+−−

−+−−=

)6.948.0(:)(

)81.068.0/0.7(:)(2

2

qqdb

dqqqaK ts

Where, q = ds / d (%); sd is the length of the whole water body in the section.

Method of judging to use formula (a) or (b):

If on the section between the BS and the MS, there is a water body within 200 m to the

BS, use:

2/))()(( bKaKK s +=

Otherwise, )(bKK s = .

S(α )—Building density tuning factor

≤−≤<++−−

≤<−−=

120

51)20lg19.0)(lg6.15(

1005)lg2530(

)( 2

a

aaa

aa

as

a—building density, calculated in percentage.

Combination usage of tuning factors

Overall path loss:

++

+++=

r

mr

u

spim

h

s

streetb

Q

QK

RK

K

K

K

aSKLL

0

0

0

)(

EET tuning factors

ERICSSON used a new set of tuning factor calculation methods in its EET software.

The following describes these factors:

streetK —street tuning factor

Same as in the Okumura-Hata model.

Kmr—suburb tuning factor


137137137137


Qo—open area tuning factor


Qr—quasi open area tuning factor


uR —rural area tuning factor


Kh—upland area tuning factor

≥∆−+∆+∆−−<∆

= 20)105.3lg538.3)(lg18.5(

2002 hKhh

h

K hfh

<∆

>∆−∆×∆−∆+∆−=100

10)2/()2

/()727.10lg0544.14)(lg419.1( 2

h

hhhh

hhK hf

The definition of h∆ is the same as in the Okumura-Hata model and h is the height of

the MS compared with whereh∆ =0.


CBAK mmsp +−= θθ 2

mθ is the mean obliquity of 25 km before and after the MS at the section on the line

between the MS and the BS got through least square. Its unit is mini radian.

Parameters A, B, and C valuate to as follows:

D(km) A B C

>60 -0.009411 0.7620 0.22

=30 -0.013400 0.6313 -0.63

<10 -0.002394 0.2057 0.12

If the value of d does not belong to the ranges listed in this table, you can calculate out

the values of A, B, and C through the linear interpolation method.

Kim—isolated hill tuning factor


138138138138

)(07.0 22

23

24

2 EDdCdBdAdhK im ++++−=

h—height of the hill

d1—distance from the BS to the peak of the hill.

d1—distance from the MS to the peak of the hill.

d1(km) A B C D E

>60 0.8492 -1.677 11.47 -30.41 19.45

=30 0.6259 -1.280 9.184 -25.19 9.790

<15 0.0498 -1.065 8.102 -23.33 4.070

For other d1 values, you can calculate out the values of A, B, C, D, and E through linear

interpolation.

Ks—sea (lake) mixed path tuning factor

When the propagation path involves an water area, there are two different situations to

consider, as shown in the following figure:

Base station

Mobile station

ds d

Base station

Mobile station

d ds

(a) Base station near land (b) Base station near waters

Tuning factor:

++−−

−+−=

)06.01868.0000789.0(:)(

)09.006893.0000579.0(:)(2

2

qqb

qqaK ts

q = ds / d (%). sd is the length of all the water body on the section.

The method of judging which of formulae (a) and (b) to be used is the same as in the

Okumura-Hata model.

S(α )—building density tuning factor

≤−≤<−−−

≤<−−=

120

51)lg74.3)(lg75.920(

1005)lg0.1926(

)( 2

a

aaa

aa

as

a—building density, counted in %.


139139139139

BS antenna effective height additional tuning factor Ht

ChBhAH bebet ++= lg)(lg 2

hbe—effective height of the BS antenna: gabgbe hhhh −+= )( .

hg—floor level of the BS.

hb—height of the BS antenna.

hga—mean altitude between the MS and the BS.

d(km) A B C

1 0.5131 11.68 -23.32

3 0.2433 14.42 -27.31

5 0.3690 15.60 -29.94

10 0.5457 17.75 -34.66

20 2.568 11.89 -30.61

40 4.289 7.019 -27.66

For other d values, you can calculate out the values of A, B, and C through linear

interpolation.

MS antenna effective height additional tuning factor H t

]9.1)(lg16.10)(lg27.10)(lg92.22[ 23 −+−−= mmmr hhhH

Combination usage of tuning factors

rt

r

mr

u

spim

h

s

streetb HH

Q

QK

RK

K

K

K

aSKLL ++

++

+++=0

0

0

)(

COST-231 model

For 1800 MHz, use the COST-231 model.


GSM900/1800



140140140140


The communication distance is 1–35 km.


γ))(lglg55.69.44()(lg82.13lg9.333.46 dhhahfL bmbbCity −+−−+=

The unit of d is km and that of f is MHz.

bCityL is the mid-value of basic propagation loss in urban areas.

hb, hm—effective heights of the BS and MS antennae, counted in m.

The effective height of the BS antenna is calculated as follows: Suppose that the BS antenna is sh away from the floor, the altitude of the BS floor is gh , the MS antenna

is mh from the floor and the altitude of the MS floor is mgh , then the effective height

of the BS antenna, hb, is the value of ( sh + gh - mgh ) and that of the MS antenna is mh .

Tuning factor of the MS antenna:

=<<−

<<−

−−−

=

mh

MHzfh

MHzfh

fhf

ha

m

m

m

m

m

5.10

city Big150040097.4)75.11(lg2.3

2001501.1)54.1(lg29.8

city smallor Medium)8.0lg56.1()7.0lg1.1(

)(2

2

Tuning factor for long-haul propagation:

>×+×++≤

= −− 20)20

)(lg1007.11087.114.0(1

2018.034 d

dhf

d

bγ

Tuning factors:


EET tuning factors

Also applicable in the COST-231 model.

Universal mode


141141141141

First proposed by ERICSSON.

(ERICSSON , MSI similar model)


GSM900/1800



The communication distance is 1–35 km. (Can be longer)


One-stage formula:

streetmddclutterbbbCity KhaLKKKhdKhKdKKL +−++++++= )(lglglglg 54321

Two-stage formula:

>−++−++++++≤+−++++++

=002221543221

0543211

lg)()(lglglglg

)(lglglglg

dddKKKhaLKKKhdKhKdKK

ddKhaLKKKhdKhKdKKL

streetmddclutterbb

streetmddclutterbbb城

There can be more stages, depending on the propagation distance and calculation

precision. Generally the one stage or two stages will do.


=MHz

MHzK

180065.156

90083.1461

2K =44.9.

3K =-13.82.

4K =-6.55.

5K —artificial environment tuning factor (it is 0 by default in cities).

dK —diffraction loss factor, valuating from 0 to 1 (generally it is 0.95 for rural areas,

0.65 for urban areas, and 0.8 for suburb areas.

dL —diffraction loss (for its calculation formula, see that for isolated hills in the

Okumura model.


142142142142

hb, hm—effective heights of the BS and MS antennae, counted in m. The unit of d is

km.

0d is a customizable stage division point. It is 1 km by default.

)( mha —as described in the Okumura model.

streetK —as described in the Okumura model. This parameter only applies to cities.

clutterK —clutter tuning factor. There are two optional methods:

A. Common method: use the clutter factor of the place where the MS lies. It is 0 by

default.

B. Improved method: as an option, select the weighted average of clutter tuning factors

of 1200 m from the MS to the BS (if the distance is less than 200 m, directly use the

clutter the place where the MS lies; if the distance is 200 m to 1200 m, use the actual

distance). The formula is as follows:

∑=

×××+

=n

iclutterclutter iKiWn

nnK

0

)]()([)1(

2

Where, clutterK —actual tuning factor (i=0)

W(i)—weight

i—subscript

n—subscript at (d-x)=1200 m

d—distance between Tx and Rx

Here, the value of n depends on the resolution of the topographical data.

1

W(d-x)

Rx-Position 200m 1200m d-x


143143143143

Topographical tuning weight of 1200 m around the Rx

(Note: The value 200 m can also be changed, for example to 150 to get a better

propagation model.)

Suppose that the BS antenna is sh away from the floor, the altitude of the BS floor is

gh , the MS antenna is mh from the floor and the altitude of the MS floor is mgh , then

the effective height of the BS antenna, hb, is the value of ( sh + gh - mgh ) and that of the

MS antenna is mh .

Tuning factors:

Different clutter tuning factors can both be set by the use (if there is already an

empirical value) and be got through test data tuning.

COST-231-Walfish-Ikegami model

The foundation of the macro cellular model is: the propagation loss from the BS to the

MS depends on the environment around the MS but within 1 km it is severely affected

by the buildings and street directions around the BS. Therefore, this model does not

apply to prediction for within 1 km.

The COST-231-Walfish-Ikegami model applies to propagation loss prediction for from

20 m to 5 km, serving as macro cellular model or micro cellular model. Micro cellular

coverage prediction requires detailed street and building data, not approximate value.


GSM900/1800.

This model applies to propagation model loss prediction in big, small, and micro cells.


Video on demand (VOD):

)()( lg20lg266.42 MHzkmb fdL ++= limited to md 20≥ .

Non-VOD:

msdrtsb LLLL ++= 0

<

>+∆++−−=

)0(0

lg20lg10lg109.16

rts

MobilerooforiMobile

rtsLif

hhLhfL

ω


144144144144

<≤−−<≤−+

<≤+−

=oo

oo

o

oriL

9055)55(114.00.4

5535)35(075.05.2

350354.010

ϕϕϕϕ

ϕϕ

<

−+++=

)0(0

lg9lglg

msd

fdabsh

msdLif

bfKdKKLL

≤

>∆+−=

roofBase

roofBaseBase

bsh hh

hhhL

0

)1lg(18


L0—free space propagation loss.

Lrts—diffraction and scatter loss from the raft to the street.

roofBaseBaseMobileroofMobile hhhhhh −=∆−=∆

ω —width of the street (m).

f —calculation frequency (MHz).

Mobileh∆ —its unit is m.

ϕ —its unit is degree.

Lmsd—multi-barrier diffraction loss.


145145145145

⊿hMobile

hMobile

ω

b d

⊿hBase

hroof

hBase α

Base station

Incoming wave

φ

Building

（a） Environment parameter

（b）Street parameter

MS

≤<×∆−

≤≥∆−

>

=

roofBaseBase

roofBaseBase

roofBase

a

hhkmdd

h

hhkmdh

hh

K

&5.05.0

8.054

&5.08.054

54

>∆

×−

≤=

roofBaseroof

Base

roofBase

d hhh

h

hh

K1518

18

−

−+−=

cities big toApplies1925

5.1

treesdense-medium with areas

and cities medium toApplies1

9257.0

4f

f

K f

Where, Ka is the additional path loss when the BS antenna is lower than the rafts of

neighboring buildings and Kd and Kf respectively control the relations of Lmsd with

distance d and frequency f.

Tuning factors:

Can use the topographical tuning factor of the Okumura-Hata model.


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Kh—upland tuning factor




K im—isolated hill tuning factor


Ks—sea (lake) mixed path tuning factor


All these propagation models do not consider the effect of the landform. However, in

some environment the landform has a great effect on the propagation of electric waves.

Examples include buildings, groves, bamboo forests, fields of sugarcane or other crops

higher than 1.5 m, lakes, and seas.

In urban areas, indoor coverage greatly depends on the mean height, density, material,

structure, and wall thickness of buildings and directions the BS signals. As empirical

data show, due to China’s poor economical and public security status, buildings in

medium and small cities, especially in their lower floors have metal security nets at the

doors and windows, which make the penetration loss as high as 20–30 dB. As for shops

along streets, most of them use aluminum alloy door and have no windows, which also

poses a high penetration loss.

Groves, bamboo forests, and sugarcane fields has a high attenuation on electric waves,

especially 1900 MHz PCS systems. According to the test experience in Dehong, they

generally cause an attenuation of more than 30 dB. In addition, they cause fast shade

fading.

On lakes, electric wave propagation has a small attenuation. However, due to effects of

waves on the lake surface, there must be severe fading. For example, 450M wireless

access is hardly available in such areas. As for CDMA, as it is accepted by RAKE, it

must be able to overcome this situation. However, it is still never verified in such

environments.

If the condition permits, electric measurement must be conducted to find out the effects

of landform or propagation of electric waves. In link budgeting, it is also necessary to

consider the effect of the landform to get of more accurate coverage radium.


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The WCDMA system uses the 2000 MHz frequency band. Test data show that the

traditional universal propagation model still applies at 2000 MHz, only that model

tuning is needed. The planning software AIRCOM can adjust propagation models.

Macro cells use the universal model, as described in the following:

RxLev=EiRP-Path_Loss

Path_Loss=K1+K2log(d)+K3(Hms)+K4log(Hms)+K5log(Heff)+K6log(Heff)log(d)+K

7(Diffraction Loss)+Clutter_Loss

Where, RxLev is the received signal power level (dBm);

EiRP is the BS effective radiated power (dBm);

Path_Loss is the mid-value of propagation path loss (dB);

K1 is the attenuation constant;

K2 is the distance attenuation factor;

K3 and K4 are MS antenna height tuning factors;

K5 and K6 are BS antenna height tuning factors;

K7 is the diffraction tuning factor

Clutter_Loss is clutter and landform attenuation tuning value;

d is the distance between the BS and the MS (km);

Hms is the effective height of the MS antenna (m);

Heff is the effective height of the BS antenna (m).

The effective height of the BS antenna is calculated as follows: Suppose that the BS antenna is sh away from the floor, the altitude of the BS floor is gh , the MS antenna

is msh from the floor and the altitude of the MS floor is mgh , then the effective height

of the BS antenna, hb, is the value of (sh + gh - mgh ) and that of the MS antenna is

msh .

6.3.5 Transmission Model Tuning

6.3.5.1 Transmission Model Tuning Criterion

A multitude of engineering experience shows that when the land is flat, the model can

be considered as usable if the standard difference between the actually measured data


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and the predicted data is not larger than 8 dB (or 11 dB for uplands) and the mean

value of actually measured data is not 3dB larger than the predicted data. The

verification process is as follows:

First, select several test points, for example 9, from a typical environment to uniformly

collect data. Then, provide 6 test points for model tuning. At last, use the tuned model

to predict the signal strength of another three similar environments to get the standard

difference and mean value difference.

You can understand the model judging criterion as follows: when predicted with a

usable model (the standard difference is not larger than 8 dB and the mean-value

difference is not larger than 3 dB), 68% points will have a difference within (-8–

+8)dB from the actual measured data and 32% points will have a difference beyond

that range.

There are two methods to adjust the propagation model. One is through curve fitting

and the other is through network planning software. The following describes these two

methods.

6.3.5.2 Propagation Model Tuning Through Curve Fit ting

The universal propagation model is as follows:

Pathloss = k1 + k2*lg(d) + k5*lg(Heff) + k6*lg(Heff)lg(d)

Where, d is the distance from the mobile test equipment to the BS antenna, counted in

km, and Heff is the effective height of the BS antenna, counted in m. Now, we take the

absolute height of the antenna as its effective height.

The measured sample data cannot be used to calibrate all of the four parameters k1, k2,

k5, and k6.If the data are from a same site and the drive test route is basically all on

flatland, the effective height of the antenna can be considered as consistent. You can fix

the value of k5 to -13.82 and that of k6 to -6.55.Therefore, you only need to adjust the

k1 and k2 parameters and this does not affect the accuracy.

However, if the test data are from sites of different antenna heights, it is incorrect to

mix all the data points and analyze them together. Instead, adjustment should be done

first. The following two sections describe test data analysis methods.

1. Analysis method for data from a same test site

If all data are from a same site and the drive test route is basically at the same altitude


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as the BS, we can directly analyze the data samples to solve a simple equation to

get a rough universal model tuning result.

First, according to the test data and the antenna direction diagram, calculate out

the propagation loss at each sample point. Make the xy coordinate of the

distance logarithm and the corresponding path losses and then linearly fit the

sample data points through the least square method. According to the intercept

and gradient, we can find out the solutions to k1 and k2 of the universal model.

In practice, for the coordinate used to fit the straight line, the unit of the

horizontal axis is logarithmic meter and that of the vertical axis is dB. As the

distance unit used in the universal model is km, we can get the following

equation set:

k2 + k6 * lg(Heff) = gradient of the fitted line (1)

k1 – 3 * k2 + k5 * lg(h) – 3 * k6 * lg(Heff) = intercept of the fitted line (2)

As Heff is a constant and the value of k5 and k6 are fixed, now we can work out

the solutions of k1 and k2.

2. Analysis method for data from different sites

If the data are from different sites which have different antenna heights, it will

not do to simply place all sampled pass loss data in one coordinate to fit the

straight line. This is because they correspond to losses calculated out using the

propagation model under different antenna heights and a simple [logarithmic

distance, path loss] coordinate cannot reflect this. A straight line so fitted will

make no sense.

To merge these data, we must first process them to compensate for differences

brought by different antenna heights.

When the antenna heights are h1 and h2, we can work out the difference of the

path losses with a same distance d through the following formula (note that the

unit of d is km).

∆pathloss = k5 lg(h1/h2) + k6lg(d) lg(h1/h2) = (k5 + k6lg(d) ) * lg(h1/h2)

Therefore, we can set a reference antenna height h1, let that of the data source

cell be h2, and add a compensation value worked out through the above formula

to each data sample to use them to tune the propagation model.


150150150150

If the horizontal axis unit used is logarithmic meter, the compensation value

should be calculated as follows:

∆pathloss = (k5 – 3k6 + k6lg(d) ) * lg(h1/h2) —the unit of d is meter

In practice, the values of k5 and k6 are the same as in the Hata model, that is,

-13.82 and -6.55.

6.3.5.3 Propagation Model Tuning Through Network Pl anning Software

1. Roughly tuning the model

The universal model in Hata equations is as follows:

RxLev=EiRP-Path_Loss

Path_Loss=K1+K2log(d)+K3(Hms)+K4log(Hms)+K5log(Heff)+K6log(Heff)log(d)+K

7(Diffraction Loss)+Clutter_Loss

In this method, information about the signal transmit system is all set to the planning

software so that we can accurately work out the EiRP of the signal source. Of all the

information, the antenna direction, tilt, and direction diagram and the location of the

signal source are very important to the accuracy of the model.

The propagation model is mainly tuned through the scatter diagram drawn by the

difference between the electric wave signal strength predicted according to the untuned

model and that measured and the corresponding propagation distance. Actually, none of

K3, K4, and K5 is easy for tuning or analysis, because as weights they correspond to a

reference that is the effective antenna height of the MS or transmit source and it is

uneasy to collect a multitude of data through changing the effective antenna height of

the MS or transmit source. In practice, for trial networks K3 and K4 are both used

without being calibrated and K5 evaluates to -13.82 as in the COST-231 model. Their

inaccuracy is made up through calibrating K1.For the same reason, K6 also evaluates

to its value in the COST-231 model, -6.55. Its inaccuracy is made up through adjusting

K2.

Adjustment of K1 and K2

In model tuning, we first adjust the gradient factor K2 to make Gradient in the Error. vs

log(distance) diagram to be 0dB/dec and then adjust the intercept factor K1 to make

Intercept in the Error. vs log(distance) diagram to be 0dB, as shown in the following

figure:


151151151151

Error. Vs log (distance) Diagram

We can tune the model according to the output values of Gradient and Intercept. When

Gradient=0dB/dec and Intercept=0dB, through analysis we can see that the overall

mean error of the model is 0 in the outputted report. However, the mean error of other

clutters is not necessarily 0 (generally the mean error of none of these clutters is 0,

because the clutter factor is still tuned).

Adjustment of K7

The diffraction factor, K7, is used for consideration of diffraction loss in electric wave

propagation. There are many methods to calculate the diffraction loss, all needing clear

description of an accurate clutter (building, tree, and so on).As the diffraction factor

only takes a part when there is no line of sight (LOS) signals from the transmitter to the

receiver and K7 cannot include LOS signals, Non-LOS signals must be filtered out.

After these signals are filtered out, we can adjust K7 to make the model mean error in

the analysis output report evaluate to 0.

Tuning of K6 and readjustment of K1

After K7 is worked out, recover the LOS signals filtered out. Then output the Error. Vs

log (distance) diagram to see if the value of Gradient is 0. If it is not, adjust K6 to make


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it be 0.After that, check if the model mean error in the analysis output report is 0. If it

is not, adjust K1 to make it be.

Combined adjustment of clutter and K6

According to the adjustments made earlier, check if the mean error of each clutter is 0

in the analysis output report. If that of a clutter is not, adjust the clutter offset to make it

be. After the clutter offsets are adjusted, maybe neither of Gradient and Intercept is 0 in

the Error. Vs log(distance) diagram. In that case, adjust K6 to make Gradient be 0.

However, this may make the mean errors of some clutters be non-zero again and we

need to adjust these clutters’ clutter offsets. Therefore, we need to adjust clutter offsets

and K6 in turn to make the final fitted straight line of the error point coincide with the

horizontal axis, that is, make both the mean error of each clutter and Gradient be 0.

After the rough adjustment, we get a rather accurate propagation model. To make the

model more accurate, we can make fine tuning on it.

2. Finely tuning the model

Fine tuning of the propagation model is to tune the following aspects of the

propagation model based on the rough tuning.

Fine tuning of the clutter tuning factor

In the model, there are two methods to set the clutter propagation loss. One is the offset

effect of clutters at the drive test point on the signal strength of electric waves received.

In this method, the parameters to adjust are the propagation loss offset factors of

different clutters. The other method of reflecting clutters’ effect on propagation of

electric waves is considering the effect of all clutters from the drive test point to the

cable connecting to the signal source. The following diagram describes this method:


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According to this figure, to calculate the additional propagation loss caused by clutters

we can consider all clutters that are on the line from the MS to the transmit BS and are

dthrough away from the MS. The loss contributed by each kind of clutter depends on the

proportion of clutters of the kind in the dthrough as well as their distance from the MS. As

shown in the figure, weights ranging from 0 to 1 will be added to calculate the losses

caused by clutters of different distances on the path. This means the effect of remote

clutters will be smaller than that of near clutters. When using this method to adjust the

model, we need to set the influence quantity (the unit is dB/km) of each kind of clutter

on the propagation in unit distance and the range in which clutters will affect the

propagation, that is, dthrough.

As all measured data all lies on roads and roads belong to the “urban open area” clutter

type, only considering effects of clutters at the drive test point cannot reflect the

propagation features of different clutters. In practice, the method shown in the above

figure is used to adjust the model. Considering various clutters on the propagation path,

this method can better reflect the influence quantity of each clutter.

First, ascertain the value of dthrough. From the view of geometry, dthrough should be at

least 250 m in a flat area if the signal source is 40 m high, the drive test point is 1 km

away from the signal source, and the clutters affecting propagation of electric waves

have a mean height of 10 m. In tuning, we must select a proper dthrough based on

comprehensive consideration.

After the range of dthrough is determined, start to adjust the penetration loss caused by

each kind of clutter. At the beginning of tuning clutter losses, for a clutter type whose

penetration loss value is to be adjusted, it is recommended to select data of clutters to

be examined in dthrough from the test data as main clutter data. As these test points

mainly reflect the characteristics of the clutters to examine, we can adjust the

penetration loss caused by clutters of the type. The adjusting method is still to observe

the scatter diagram of differences between predicted values of test points selected and

measured data to make the fitted straight line of the error point coincide with the

horizontal axis.

Fine tuning of K7

In the network planning software, there are various methods to calculate the diffraction

factor, K7. We can select different algorithms to readjust K7 so as to get a propagation

model of a smaller mean value and variance.


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Adjustment of K3, K4, K5, and K6

In rough adjustment of the model, no factor only related to the BS or MS antenna

height is adjusted. In addition, network planning software provides many a method to

calculate antenna effective heights. Therefore, we can select different algorithms to

adjust the parameters to get the tuned value of each factor that is of the smallest mean

value and variance.

Two-stage model

As generally, near propagation environments have a great difference from the remote

ones, it is better to adjust the propagation model in the two-stage method to better

predict propagation losses of remote and near fields. To select the demarcation of

remote and near fields, refer to the Lee formula, d=4h1h2/λ.

Operations of tine tuning of the propagation model are the same as in rough tuning.

6.3.6 Propagation Model Tuning Result

The result of propagation model tuning is outputting a tuned universal propagation

model that satisfies the requirements on mean value and variance and includes tuning

factors K1–K7 and the loss offsets of different clutters and landforms.

Mean Error is the statistical mean difference between predicted values and those

measured in drive test, RMS Error is the mean variance, and Std. Dev. Error the

standard difference. After you make Mean Error be 0 through setting clutter offsets,

RMS Error is equal to Std. Dev. Error.

RMS Error≤8dB is the criterion for judging the fitted degree, or convergence, of the

adjusted data with the prediction model. It is generally believed in the industry that

when a model whose RMS Error is ≤8dB is used to predict a new area of a similar

landform and clutters, the mean prediction difference will be ≤3dB. Therefore, if RMS

Error≤8dB, the model can be used as a foundation of network planning.

Generally speaking, we still use the standard difference as the foundation for judging.

Propagation model studies show that the standard difference of the propagation model

should be within 8 dB in flat areas or 11 dB in uplands. Generally, the standard

difference increases with the test distance and the frequency.

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7 The Principal and Selection of Antenna

7.1 Overview of Base Station Antennae

Knowledge Point

This chapter introduces the development and the trends of the domestic antenna

industry in terms of basic concepts, principles, structure and classifications.

7.1.1 Development of Industry Technologies of BS An tennae

In 1897 Guglielmo Marconi (1874~1937) invented antenna and achieved the first ever

wireless communication in history. With over half a century’s development, antenna

technologies have been widely applied in military communication and civil

communication. Antenna becomes an industry. In a cellular mobile communication

system, base station (BS) antenna is the converter of the electrical signal of the

communication equipment and the spatial radio electromagnetic wave. It is the

connection hub of spatial wireless communication. The cellular communication system

requires the reliable communication from the BS to the mobile station (MS). The gain,

coverage direction, beam, available drive power, antenna configuration, polarization

mode, and other factors all affect the communication performance between systems.

7.1.2 Technical and Market Situations of Chinese An tenna Enterprises

According to related information, concerning the civil BS antenna, intelligent antenna,

and Bluetooth antenna, which are technically heavy-loaded in mobile communication,

spread communication, and microwave communication, the market share of the

domestic antennae of those types counts for only 20% or so. The scale and strength of

the national antenna enterprises are still far behind those of the foreign famous antenna

enterprises. According to incomplete statistics, as of the first half of 2002, the

communication antenna enterprises in the country amount to 100, most being medium-

and small-scale enterprises. Based on the annual production and the according sales

revenues, only Xi'an Haitian Antenna Technologies, Shenzhen Mobile Technologies,

Mobile Antenna Technologies, Kenbotong Communication, Shenglu Antenna, Tongyu

Communication Equipment, and a limited few reach the scale of 200 employees and a


156156156156

sales revenue of RMB over 30 million.

Generally speaking, the national communication antenna industry of China is

characteristic of large number, small scale, and weak strength.

7.1.3 Competitive Advantages of Foreign Antenna Ent erprises

The competitive advantages of foreign antenna enterprises are strong capital support,

high recognition of brand name, and in-depth human and technical reserve. Among

them, there are internationally well-known brand names that have been developed for

over half a century, with a sales revenue of over USD 2 billion. In the domestic market,

the largest domestic antenna enterprise has a sales revenue of only RMB 100 million, a

fragment of one percent of that of the foreign antenna heavyweights.

After the accession to the WTO by China, ADC, Andrew, Comtel Technology, and

Kathrein are the pioneer well-known international antenna enterprises that invested in

China and established joint ventures. They stir great impact on the national antenna

enterprises of China.

7.1.4 Development Direction of Antenna Industry

The development history of antenna is just 100 years. As radar is applied in military

facilities, antenna is critical to the countries and attracts much concern. In terms of

hardware, antenna is rather mature. To adapt to the requirements of modern

communication, the R&D of antenna branches off in a few directions: high integration,

broadband orientation, and multi-frequency and intelligent functioning. Currently,

dual-polarization, electronically adjustable downtilt, and multi-frequency multiplexing

antennae are gradually seeking their ways into commercial applications. Intelligent

antenna technologies have gained much ground in its development.

After twenty years’ development, the domestic antenna brands are shortening the gap

with foreign brands, and in terms of some indices, are at the same level as foreign

brands. In the country, the brand name recognition and credibility of domestic antennae,

but the gaps of capital and human resources reserve are still wide. The advantage of

domestic antennae lies in medium price, good service, and close distance to suit the

needs of communication construction.


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7.2 Principles of Antenna Radiation

One of the important functions of antenna is to efficiently convert the electrical signal

of the transceiver into electromagnetic wave in the free space, or vice versa. The

efficient and capability of the electromagnetic wave of the antenna radiation is a

professional technology. The following is about some most basic radiation principles of

the antenna dipole.

7.2.1 Electromagnetic Wave Radiation

Principles of electromagnetic wave radiation: The vibration of electron and magnetron

generates an alternating field or a magnetic field, with the two converting mutually into

each other to form electromagnetic wave that radiates at the speed of light. When the

conductive wire has motion of an alternating current, it causes the radiation of

electromagnetic, with the radiation capacity related to the length and shape of the

conductive wire. As shown in Fig. 7.2-1a, if the distance between the two conductive

wires are short, the field is restricted between the two conductive wires, which causes

weak radiation. If the two conductive wires are separated with a wider distance, as

shown in Fig. 7.2-1b, the field promulgates to the surrounding space, which causes

strong radiation.

Please note that when the length L of the conductive wire is smaller than λ, the

radiation is weak. When the length L increases to the level that is comparable with the

wavelength, the current on the conductive wire will increase sharply, which causes

relatively strong radiation.

a b

Fig. 7.2-1

Antenna itself is an alternating current oscillator. The process as shown from Fig. 7.2-1a

to Fig. 7.2-1b can be considered the evolving process of the antenna. The modulated


158158158158

high-frequency signal from the transmitter is sent via the feeder to the antenna, which

converts the high-frequency current energy into related electromagnetic wave energy

and radiates it to the space. It is the transmitting process of the antenna. Conversely, the

electromagnetic wave radiated in the space is converted at the antenna into

high-frequency current. It is the receiving process of the antenna.

Note

Antenna has a reverse capability which means that the transmitting antenna can work

as the receiving antenna, or vice versa. In addition, it means that the parameters of the

antenna as transmitter and the parameters of the antenna as receiver are kept unchanged.

It is the reciprocity theorem of antenna.

7.2.2 Symmetrical 1/2 wavelength Dipole

According to the Transmission Line Theory, when the length of the conductor is integer

multiples of 1/4 wavelength, the conductor shows oscillation feature on the frequency

of the wavelength, with the strongest radiation. However, as the part of the radiation

that exceeds 1/2 wavelength is opposed-phase and counteracts the radiation, the total

radiation effect is reduced. In this regard, antenna usually adopts 1/4 or 1/2 wavelength

as dipole length unit.

A dipole with the two rods of the same length is called symmetrical dipole. With the

length of the rod 1/4 wavelength, and the full length being 1/2 wavelength dipole, it is

called 1/2 wavelength symmetrical dipole, as shown in Fig. 7.2-2.

1/4

1/4

1/2

1/4

1/4

1/2

Wavelength

Wavelength

WavelengthWavelength

Wavelength

Fig. 7.2-2 1/2 Wavelength Symmetrical Dipole

In addition, there is another alternative model of 1/2 wavelength symmetrical dipole. It


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can be considered the narrow rectangle folded on the basis of a full-wavelength

symmetrical dipole, with the two ends of the full-wavelength dipole stacked. The

narrow rectangle is called folded dipole, as shown in Fig. 7.2-3.

Fig. 7.2-3 1/2 Wavelength Folded Dipole

Symmetrical dipole is the most typical and most widely applied antenna so far. A single

1/2 wavelength symmetrical dipole can be independently used, or multiple 1/2

wavelength symmetrical dipoles can form an antenna array.

7.3 Internal Structure and Classification of Common BS Antennae and Indoor Antennae

7.3.1 Directional Patch Dipole BS Antennae

Directional patch antenna is a most important BS antenna that is most widely used. The

advantages of this type of antenna is high gain, ideal sectoral antenna pattern, small

back lobe, convenient control of declination angle of the antenna pattern on the vertical

plane, reliable sealing performance, and long life cycle.

For the outer view of the antenna, please refer to Fig. 7.3-1.


160160160160

Fig. 7.3-1 Outer View of Directional Patch Antenna

7.3.1.1 Forming of High Gain of Patch Antenna

Multiple 1/2 wavelength dipoles are arranged to form a vertically placed linear array, as


Fig. 7.3-2 Vertical Antenna Pattern of 1/2 Dipole

Reflection plate is added on the side of the linear array to achieve horizontal directional

principle (take the 1/2 wavelength dipole vertical array for example), as shown in Fig.

7.3-3.


161161161161

Horizontal pattern

Reflection

plate

Dual

dipoles

Reflection

plateDual

dipoles

Fig. 7.3-3 Antenna Pattern of 1/2 Wavelength Dipole with Reflection Plate

Currently, the design of the BS directional antenna by the antenna manufacturers all

adopts the structure of a patch dipole array. The dipoles selected are of two types.

7.3.1.2 Symmetrical Dipole

Standard 1/2 wavelength symmetrical dipole (on extra dipole added to reduce the

height off the ground of the dipole and the thickness of the antenna).

Fig. 7.3-4 Symmetrical 1/2 Wavelength Dipole

7.3.1.3 Micro-strip Dipole

The alternative of the 1/2 wavelength dipole that utilizes the 1/4 wavelength

transmission theorem to form radiation.


162162162162

Fig. 7.3-5 Micro-strip Dipole

7.3.1.4 Array Structure of BS Antenna Dipoles

Coaxial dipole

array attentae45° dual-polarization micro-strip

intersection curve patch antenna

45° dual-polarization

dipole array attenae

Dual-frequency

dipole array atennae

Fig. 7.3-6 Array Structures of BS Antenna Dipoles

7.3.2 Omni Serial Feeding BS Antennae

The omni antenna adopts the serial feeding of multiple 1/2 wavelength dipoles to

implement the synthesis and enhancement of the radiation gain.


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Bottom feeding omni antenna

Bottom

feeding

Current

Amplitude

distribution

along the

cable

Fig. 7.3-7 1/2 Wavelength Dipole Serial Feeding

7.4 Concept and Significance of Antenna Technical P arameters

Knowledge Point

This chapter introduces the concepts of the technical indices of the BS antennae, and

describes the significance of the performance indices of the antennae in network

planning. Based on the classification of the antennae by performance indices, this

chapter also introduces how to select the antenna models in network planning.

7.4.1 Gain of Antenna

Gain is one of the most important parameters in the design of the antenna. By

increasing the gain value, the network coverage scope in a certain specific direction can

be increased, or the gain surplus in a specific scope can be increased. Any cellular

system is bidirectional process. At the meantime of increasing the gain value of the

antenna, the gain budget surplus of the bidirectional system is reduced.

The gain of the antenna refers to the power density ratio of the signals generated at the

same point in the space of the actual antenna and the ideal radiation unit under the

same input power condition. In other words, the gain of an antenna is the enlarged

multiple of the input power, compared with the ideal point source without direction,

concerning the radiation effect in the direction of the largest radiation. It describes

quantitatively the degree to which the antenna centralizes the input power and radiates


164164164164

it. Gain is obviously related closely with the antenna pattern. The narrower the antenna

pattern is, the smaller the auxiliary lob, and the higher the gain.

The definition of the gain of an antenna is related to the 1/2 wavelength dipole or the

omni antenna. The omni radiator assumes that the radiation powers in all directions are

equal. The gain of the antenna in a certain direction is a value of the field strength

generated in this direction over the intensity by the omni radiator in this direction.

Generally the gain of the antenna has two units: dBd and dBi. dBi indicates the field

strength in the direction of the largest radiation of the antenna, compared with the

reference value of the omni radiator (as shown in Figure 2.1). The gain of a single 1/2

wavelength dipole (as shown in Figure 2.1) is G = 2.15 dBi. The gain of the antenna

compared with the 1/2 wavelength dipole (as shown in Figure 2.1) is indicated with

dBd. Obviously, the gain of a single 1/2 wavelength symmetrical dipole can be

indicated with G =0dBd.In this regard, dBd and dBi are applied to measure the fixed

dB difference of the antenna gain (as shown in the right of Figure 2.1), i.e., 0dBd =

2.15dBi.

Fig. 7.4-1 Different References of dBi and dBd

Currently the gain range of the domestic and foreign BS antennae varies from 0dBi to

over 20 dBi.

The gain of the antenna for indoor cellular coverage generally selects 0 to 8 dBi. The

outdoor BS ranges from omni antenna gain 9 dBi to directional antenna gain 10 dBi in

most cases. The antennae with a 20 dBi or so narrow beamwidth are usually applied for

the coverage of sparsely populated express highways.

7.5 Antenna Radiation Pattern

The antenna radiation pattern is the pattern based indication of the antenna radiation

feature in the spatial coordinate. It includes main lobe and side lobe. In particular, the

main lobe is the radiation lobe that covers the direction of the largest radiation. The


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side lobe is the radiation lobe, other than the main lobe, that radiates other directions.

The BS antenna radiation pattern can be divided into two main types: omni radiation

pattern and directional radiation pattern, corresponding to omni antenna and directional

antenna, as shown in Fig. 7.5-1. In the left of the figure, it is the horizontal sectional

view and the dimensional radiation pattern of the omni antenna. In the right of the

figure, it is the horizontal sectional view and the dimensional radiation pattern of the

directional antenna.

1. In the case of omni antenna, even radiation is shown in the horizontal plane for

360°, or non-directional. In the vertical direction, it is indicated as a beam with a

certain beamwidth. Generally the smaller the width of the lobe is, the larger the

gain is. For an omni antenna, the radiation intensity in all directions on the same

horizontal plane is equal in theory. It is applicable to the omni cell.

2. In the case of directional antenna, radiation in a scope of a certain angle is

shown in the horizontal plane, or directional. In the vertical direction, it is

indicated as a beam with a certain beamwidth. Like omni antenna, generally the

smaller the width of the lobe is, the larger the gain is. In the figure, the red part

is the metal reflection plate in the directional radome. It enables the direction of

the radiation of the antenna in the horizontal plane. It is applicable for the

coverage of sector cell, with a small coverage, high density of population, and

high utility efficient.

Fig. 7.5-1 Antenna Radiation Pattern


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According to the networking requirements, BSs of different types can be equipped with

different types of antennae. The basis of selecting is the above technical parameters.

For example, an omni station adopts an omni antenna with basically the same gain at

all horizontal planes. A directional station adopts a directional antenna with different

gain values on different horizontal planes. Generally, directional antenna is selected in

downtown and suburb, whereas omni antenna is selected to achieve large scope of

coverage in the countryside.

7.6 Lobe Width

The antenna radiation pattern is an index to measure the transmitting/receiving capacity

of signal in different directions. Generally, it is indicated in a chart, showing the

relationship between the power intensity vector and the angle. On both sides of the

direction of the largest radiation of the main lobe, the angle of two vectors with a drop

of 3 dB radiation intensity (drop of power intensity by half) is defined to be the lobe

width (alternatively called beamwidth, main lobe width, or half power angle), as shown

in Fig. 7.6-1a. The narrower the lobe width is, the better the direction, the longer the

functioning distance, and the stronger the anti-interference capability. Another lobe

width is 10dB lobe width. As indicated by its name, it is the angle of two points with a

10dB drop of radiation intensity (drop of power intensity to the one tenth of the

original level), as shown in Fig. 7.6-1b.

-3dB point

Peak direction

(max. amplitude

direction)

-3dB point

-10dB point

-10dB point

Peak direction

(max. amplitude

direction)

a b

Fig. 7.6-1


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7.6.1 Horizontal Lobe Width

The horizontal lobe pattern refers to the sectional view of the antenna pattern along the

section in the horizontal direction. The horizontal lobe width of an omni antenna is all

360° (right of Fig. 7.6-1). The common horizontal lobe 3 dB widths of the directional

antenna are 20°, 30°, 65°, 90°, 105°, 120°, 180° and others (left of Fig. 7.6-2).

Fig. 7.6-2 3dB BS Antenna Horizontal Lobe Width

In particular, in the cases of 20° and 30° widths, the gain is high. They are applied for

the coverage of the narrow land stripes or express highways. In the case of 65° width, it

is applied mostly in the typical three-sector BS configuration in the densely populated

city areas. In the case of 95° width, it is applied mostly in the typical three-sector BS

configuration in the suburban areas. In the case of 105° width, it is applied mostly in

the typical three-sector BS configuration in the sparsely populated areas. It is shown in

Fig. 7.6-3.

Fig. 7.6-3 Coverage of Three-sector BS Configuration


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In the cases of 120° and 180°, they are applied for the coverage of special-shaped

sectors with extra-wide angles.

7.6.2 Vertical Lobe Width

The vertical lobe 3 dB width of the antenna and the gain and horizontal 3 dB width of

the antenna are inseparable. The 3 dB width of the vertical lobe of the BS antenna is

about 10°. Generally speaking, on the condition of the similar antenna design

technologies adopted, among the antennae of the same gain, the wider the horizontal

lobe is, the narrower the vertical lobe 3dB will be.

The relatively narrow 3 dB width of the vertical lobe will generate more coverage

“dead zones”, as shown in Fig. 7.6-4. With two antennae without downtilt hung at high

places, the wide vertical lobe in read generates a dead zone with the length being OX”,

smaller than OX for that of the narrow vertical lobe in blue.

In model selection, to ensure the good coverage of the service areas and reduce dead

zones, in the condition of the same gain, the vertical lobe 3 dB width of the selected

antenna should be wide as much as possible.

Fig. 7.6-4 Selection of Vertical Lobe 3 dB Width of BS Antenna

7.7 1.1 Working Frequency Range of the Antenna

Both the transmitting antenna and the receiving antenna work in a certain frequency

range (bandwidth).For mobile communication systems, the bandwidth of an antenna is

usually its working frequency range when its VSWR does not exceed 1.5.

In practice, the working frequencies of the antenna selected shall include the required


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frequencies.

For WCDMA radio system, the working frequencies of the antenna selected shall

include the frequencies required by the protocol: uplink frequency 1920 to 1980 and

downlink frequency 2110 to 2170.

For the GSM 900 system, all the dual-frequency antennae with the working frequency

of 890-960MHz, 870-960MHz, 807-960MHz and 890-1880MHz are workable.

824-896MHz antenna is selected for the CDMA800 system.

1850-1990MHz antenna is selected for the CDMA1900 system.

In order to reduce the out-of-band interfering signals, select the antenna with the

bandwidth that merely satisfies the demand.

7.8 Polarization Modes

The polarization direction of the antenna refers to the direction of the electric field

intension in antenna radiation. If the direction of the electric field intension is vertical

to the ground, the electric wave is defined as the vertical polarized wave. If its direction

is horizontal to the ground, it is defined as the horizontal polarized wave. The other two

single polarizations, +45° polarization and –45° polarization, are applied only in

unusual scenarios. For mobile communication system, most of the single polarization

antennae apply the transmitting mode of vertical linear polarization. There are 4 kinds

of single polarization modes (Fig. 7.8-1).

Fig. 7.8-1 Common Polarization Modes of BS Antenna


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7.9 Downtilt Mode To reinforce the coverage near the BS, and try to reduce dead zone as much as possible,

and meanwhile weaken the interference on other neighboring BS, the antenna should

not be too high, and employ the downtilt mode. Through antenna downtilt, the main

lobe of the antenna inclines for a certain angle, so as to decrease the power level of

adjacent BS, i.e., decrease the interference. As shown in Fig. 7.9-1, the dead zone of

yellow low-mount antenna and green downtilt antenna, OX’’ and OX’, are both less

than the dead zone of blue high-mount antenna with no downtilt angle, OX.

Fig. 7.9-1 Comparison of Antenna Downtilt in BS

Antenna downtilt modes fall into mechanical downtilt and electrical downtilt:

Mechanical downtilt: use the mechanical mode to adjust declination angle and move

antenna. After the antenna is installed vertical to the ground, required by the

optimization of network, adjust the support at the back of antenna to change the

declination angle of antenna. Practice proves that: the best declination angle of

mechanical antenna is 1° to 5 °. When the declination angle changes within 5 ° to 10°,

the antenna pattern changes a little. While further enlarging the declination angle of

antenna, the front of the coverage is obviously dented, and both sides are pressed flat.

The antenna pattern is distorted, so the front of antenna covers insufficient area and the

interference on the BSs at both sides are strengthened, as shown in Fig. 7.9-2. Another

shortcoming of mechanical downtilt is that the back lobe of antenna will be uptilted,

interfering neighboring sectors, and the user of high layer in neighboring sectors will

be dropped.


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Fig. 7.9-2 Comparison of downtilt modes in BS

And, in daily maintenance, it is very difficult to adjust the antenna tile mechanically.

Generally, the maintainer needs to climb to the place where the antenna is installed and

adjust.

Electrical downtilt : adjust the declination angle and move the antenna electrically. The

principle of electrical downtilt is: by changing the phase of antenna vibrator of shared

linear array, change the vertical and horizontal component range, and change the

strength of component field, so that the antenna pattern is tilted. Since the field strength

of each antenna direction increases and decreases simultaneously, ensuring the antenna

direction not to change a lot after the declination angle is changed, the coverage

distance of main lobe direction is shortened, and the whole antenna pattern reduces

coverage area in the whole service cell while no interference is caused. The range of

electrical downtilt antenna is large. When it is more than 10°, the antenna pattern is not

obviously distorted, and the back lobe of antenna is tilted simultaneously, and no

interference on the subscribers in high buildings at near end will be aroused. Therefore

mechanically adjusting antenna can decrease call loss and reduce interference.

Furthermore, electrically adjusting antenna enables adjusting declination angle of

vertical antenna pattern when the system is not stopped, monitoring the result of

adjusting in real time.

Use the electrically adjusting antenna in the area with heavy traffic and dense BSs. Use

traditional mechanical antenna in the suburbs and remote area with light traffic and

sparse BSs, and only requiring coverage.

7.10 Front/Back Ratio of Antenna

In the antenna pattern, the ratio of max. value of front and back lobes is called


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front/back ratio, recorded as F/B. The front/back ratio of antenna indicates how good is

the suppression on back lobe. The bigger is F/B, the smaller is the back radiation (or

receiving) of the antenna, and the less possible is the trans-coverage of the back lobe

aroused.

The formula of F/B ratio is:

F/B=10Lg (forward power density)/(backward power density)

7.11 Input Impedance of Antenna, Zin

Antenna can be regarded as a resonance circuit. One resonance circuit has its

impedance which is required to be matched. The circuit connected with antenna must

have the same impedance as antenna. Definition: The ratio of signal current at the input

end of antenna and the signal current is called impedance of antenna. The best scenario

of antenna and feeder connection is that the antenna impedance is resistance and equals

the characteristic impedance of feeder. At this time, there is no power reflection and the

feeder end, and no standing wave at the feeder. The change of antenna impedance as

frequency changes is smooth.

The antenna matching is to clear the reactance component of antenna impedance,

making the resistance component nearest to characteristic impedance of feeder. Seen

from the formula, the impedance has resistance component Rin and reactance

component Xin, i.e., Zin = Rin + j Xin. The reactance component may weaken the

extraction of signal power done by antenna. Therefore, try to make reactance

component as zero, i.e., try to make the impedance of antenna as pure resistance.

In fact, even in the antenna very well designed and adjusted, its impedance includes a

very small reactance component value. Generally, the antenna impedance of mobile

communication is 50 Ω.For any antenna, make adjustment through the antenna

impedance. Within the required work frequency range, the real part of impedance is

very small and imaginary part is very close to 50 Ω, so that the antenna impedance is

Zin = Rin = 50 Ω. This is necessary to ensure the impedance of antenna and that of

feeder to be well matched.

7.12 Antenna VSWR

Antenna VSWR is the index indicating how much the antenna feeder is matched with


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BS (transceiver).It measures the antenna performance by taking the antenna as the

transmitted and reflected power ratio while transmitting antenna. VSWR is decided by

the impedance of antenna feeder system.

Definition of VSWR:

0.1min

max ≥=U

UVSWR

Umax: In the place where the phase of incident wave is the same as that of reflecting

wave. Adding voltage amplitude is the max. voltage amplitude Umax, forming wave

loop.

Umin: In the place where the phase of indecent wave and that of reflection wave are

opposite, the difference of voltage amplitudes is min. amplitude Umin, forming wave

joint.

The generation of VSWR: because the incident wave power is transmitted to the

antenna input end and is not completely absorbed (radiation). Reflection wave is

generated and stacked to generate VSWR. The value of VSWR is between 1 and

infinite. VSWR is 1, indicating full match. VSWR is infinite, indicating full reflection

and full mismatch. The more is VSWR, the more is reflection, and the worse is match.

7.13 Side Lobe Suppression and Zero Filling

Since the antenna is normally installed in the iron tower and the top of high building to

cover the service area, the upward side lobe at the vertical face should be suppressed,

especially the first big side lobe. It can reduce unnecessary waste. Meanwhile,

strengthen the zero compensation of downward side lobe, so that the null depth in the

antenna pattern of this area is shallow, to improve the coverage in the area near the BS,

and reduce the dead zone and blind spot in the area near the BS. Fig. 7.13-1 is the

comparison of the antenna in the BS with and without null fill-in. The horizontal

coordinate is the distance from the BS, and the vertical coordinate is the signal strength

value on the ground.


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Fig. 7.13-1 Comparison of the Antenna in the BS with and without Null Fill-in

Null fill-in value of antenna = (First null amplitude value in vertical direction / max.

amplitude value in the radiation direction)%

= 20log (First null amplitude value in vertical direction /

max. amplitude value in the radiation direction) dB

To ensure better coverage of the service area, the antenna with no side lobe suppression

nor null fill-in can not be used.

7.14 IM 3rd Order

The IM.3rd order of most foreign brands can reach -150dBC@2×43dBm.While

common IM.3rd order of antenna is only -130dBC@2×43dBm , related to the antenna

design and connector selection. Since the receiving signal of BS is much weaker than

the transmitting signal, once the inter-modulation products of the transmitting signal of

multi-path frequencies fall into receiving band, the BS can not work normally.

7.15 Isolation between Ports

While multi-port antenna is used, the isolation between ports should be more than


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30dB.For example, for two different polarization ports of dual-polarization antenna,

two ports of different bands of outdoor dual-frequency antenna, four ports of

dual-frequency and dual-polarization antenna, the isolation should be more than 30dB.

5.4 Radio Parameters of Antenna

Antenna is a part of transceiver system and the key component of wireless

communication system. In terms of radio network planning, what we care for cover

two factors: electrical parameters and engineering parameters.

7.16 Antenna Radiation Pattern

The antenna radiation pattern is the pattern based indication of the antenna radiation

feature in the spatial coordinate. It includes main lobe and side lobe. In particular, the

main lobe is the radiation lobe that covers the direction of the largest radiation. The

side lobe is the radiation lobe, other than the main lobe, that radiates other

directions.The narrower the width of the lobe, the more the direction functional and the

transfer distance and anti-interference effect are enhanced.

Figure 7.16-1 65°specified direction antenna horizon lobe

Figure 7.16-2 65°specified direction antenna vertical lobe


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Figure 7.16-3 Omni-direction antenna horizon and vertical lobe

7.17 Gain of Antenna

Gain is one of the most important parameters in the design of the antenna. By

increasing the gain value, the network coverage scope in a certain specific direction can

be increased, or the gain surplus in a specific scope can be increased. Any cellular

system is bidirectional process. At the meantime of increasing the gain value of the

antenna, the gain budget surplus of the bidirectional system is reduced.

The gain of the antenna refers to the power density ratio of the signals generated at the

same point in the space of the actual antenna and the ideal radiation unit under the

same input power condition. In other words, the gain of an antenna is the enlarged

multiple of the input power, compared with the ideal point source without direction,

concerning the radiation effect in the direction of the largest radiation. It describes

quantitatively the degree to which the antenna centralizes the input power and radiates

it. Gain is obviously related closely with the antenna pattern. The narrower the antenna

pattern is, the smaller the auxiliary lob, and the higher the gain.

Figure 7.17-1 Ideal point sourse


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Figure 7.17-2 Omni-direction antenna

Figure 7.17-3 the comparison of Omni-direction antenna and Ideal point sourse

7.18 Input Impedance of Antenna, Zin

Antenna can be regarded as a resonance circuit. One resonance circuit has its

impedance which is required to be matched. The circuit connected with antenna must

have the same impedance as antenna. Definition: The ratio of signal current at the input

end of antenna and the signal current is called impedance of antenna. The best scenario

of antenna and feeder connection is that the antenna impedance is resistance and equals

the characteristic impedance of feeder. At this time, there is no power reflection and the

feeder end, and no standing wave at the feeder. The change of antenna impedance as

frequency changes is smooth.

The antenna matching is to clear the reactance component of antenna impedance,

making the resistance component nearest to characteristic impedance of feeder. Seen

from the formula, the impedance has resistance component Rin and reactance

component Xin, i.e., Zin = Rin + j Xin. The reactance component may weaken the

extraction of signal power done by antenna. Therefore, try to make reactance

component as zero, i.e., try to make the impedance of antenna as pure resistance.

In fact, even in the antenna very well designed and adjusted, its impedance includes a

very small reactance component value. Generally, the antenna impedance of mobile

communication is 50 Ω.For any antenna, make adjustment through the antenna

impedance. Within the required work frequency range, the real part of impedance is

very small and imaginary part is very close to 50 Ω, so that the antenna impedance is

Zin = Rin = 50 Ω. This is necessary to ensure the impedance of antenna and that of

feeder to be well matched.


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7.19 Antenna VSWR

A proper VSWR index is to balance the number of lost power and manufacturing cost.

In mobile communication system, VSWR is required to be less than 1.5, and VSWR in

practice should be less than 1.2

A too high VSWR may decrease the coverage of BS, and increase the interference

inside the system, influencing the service performance of BS.

7.20 Antenna Polarization

The polarization modes of electromagnetic wave may be divided into linear polarized

wave and circular polarized wave. The linear polarized wave may be divided into

horizontal polarized wave and vertical polarized wave. The circular polarized wave

may be divided into clockwise polarized wave and anti-clockwise polarized wave

according to the different rotation directions of the electric field. Most of the BS

antennae apply linear polarization mode.

Combine the vertical polarization antenna and the horizontal polarization antenna

together, or combine +45° polarization antenna and –45° polarization antenna together,

a new kind of antenna, the dual-polarization antenna, will be combined. Currently,

most of the dual-polarization antennae apply ±45° dual linear polarization mode. As a

dual-polarization antenna is assembled by combining two antennae with orthogonal

polarization packed in the same antenna cover (Fig. 7.20-1), the number of the

antennae installed will be greatly reduced if apply dual-polarization antenna, which

will result in the simplification of the antenna installation process, the reduction of the

cost and the saving of the space for antenna installation.

Fig. 7.20-1 Dual-polarization BS Antenna


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7.21 Front/Back Ratio of Antenna

The formula of F/B ratio is:

F/B=10Lg (forward power density)/(backward power density)

Backward

power

Forward

power

Fig. 7.21-1 Antenna F/B Ratio

Antenna F/B is related to the electrical dimensions of reflecting board of antenna. Big

electrical dimensions provides better F/B. For example, 3dB horizontal lobe and 65°

wide antenna is larger than 3dB horizontal lobe and 90° wide antenna, therefore, F/B of

3dB horizontal lobe and 65° wide antenna is better than that of 3dB horizontal lobe and

90° wide antenna. F/B of antenna is generally 25-30dB. Prefer to selecting the antenna

with F/B as 30.And F/B of outdoor antenna is generally more than 25dB. Since the size

of cell antenna is small, the F/B range of antenna should be larger.

7.22 Azimuth Angle of Antenna

Azimuth angle of antenna is an important project parameter. Modifying the azimuth

angle of antenna is very important to the network quality of mobile communication. On

the one hand, accurate azimuth angle of antenna can ensure that the actual coverage of

BS is the same as the expected coverage, ensuring the running quality of the whole

network. On the other hand, adjusting the azimuth angle properly according to the

traffic or the specific situation of the network can better optimize the existing mobile

communication network.

According to ideal model of cell mobile communication, directional BS is divided into

three cells, i.e.,:

Cell A: azimuth angle 0 degree, antenna directing north;

Cell B: azimuth angle 120 degree, antenna directing south east;


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Cell C: azimuth angle 240 degree, antenna directing south west;

But in actual network, we may adjust the azimuth angle of antenna. Normally to adjust

azimuth angle of antenna is based on the following three scenarios:

1. Because of the topology, such as tall building, high mountain and water surface

etc., the signal may be refracted or reflected, so that the actual coverage is quite

different from the ideal model. Then we may properly adjust the azimuth angle

of antenna according to actual network situation, to ensure the signal strength in

the area of weak signal, so as to optimize the network;

2. On the other hand, the difference of population density leads the unbalance of

traffic in the cell the antenna covers. We may adjust the direction. We may adjust

the azimuth angle of antenna to balance the traffic.

3. In the dead zone or the area with weak signal, we can also adjust the azimuth

angle of antenna to optimize the network.

7.23 Antenna Height

Antenna height is also called hanging height of antenna, generally referring to the

vertical distance from the central position of antenna to the floor. Antenna height has

strong infect on path loss. While the parameters of receiver and transmitter are fixed,

the coverage area is in direct ratio with the antenna height.

On one hand, the antenna height should be higher than the average height of the

buildings in the coverage area. On the other hand, the antenna can not be too high,

avoiding interference on neighboring area. Based on the density and average height of

current buildings, the proper antenna in cities is 35 meters, whereas the proper antenna

height in the countryside is 50 meters.

7.24 Downtilt Mode

Define the angle between the direction of the largest gain of vertical lobe and

horizontal direction as antenna declination angle. Actually, the value of antenna

declination angle is directly related to antenna height, coverage radius, vertical lobe of

antenna, electrical downtilt parameter. If the covering radius is fixed, the higher the

antenna is, the bigger the needed tile angle is. On the contrary, if the antenna height is

fixed, the smaller the covering radius is, the bigger the needed antenna downtilt is.


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In the city with dense BSs, the BSs may easily interfere with each other. To ensure

most power to radiate in the coverage area, and decrease the interference on adjacent

cells, while setting the initial declination angle of antenna, the half power point on the

major plan of the antenna should point to the edge of coverage area. The formula is

follows:

α = act(H/L)X(180/π)+(β/2)-γe

In the suburb, countryside, country road, and sea surface etc., to make the coverage as

wide as possible, decrease the initial declination angle, point the max. gain point of

main lobe to the edge of coverage area. The formula of declination angle is follows:

α = act(H/L)X(180/π)-γe

In the above formulas,

α is the initial declination angle of the antenna (unit: degree).h

H indicates the valid height of BS, that is, the difference of the hanging height of

antenna and the average height of surrounding coverage area (unit: meter).

L indicates the edge distance needed to be covered from the antenna of the BS to the

sector (unit: meter).

β indicates the vertical lobe width of the antenna (unit: degree).

γ e indicates the declination angle of the antenna (unit: degree).

5.7 Classification of Antenna

From function: Communication Antenna, TV Antenna and Radar Antenna

From frequency band: Short-wave Antenna, Ultrashort-wave Antenna and

Micro-wave Antenna

From outline: Linear Antenna and Plane Antenna

From direction: Directional Antenna and Omni-directional Antenna

7.25 Antenna Parameter Examples

1. Take Kathrein antenna for example to introduce the parameter value of outdoor

antenna.


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1) 65° direction ±45° dual-polarization antenna

UMWD-06516-4D ± 45° Diversity Panel

Frequency (MHz) 1710 -

1880

1850 -

1990

1900 -

2170

Gain dBd/dBi 15.3/17.4 15.6/17.7 15.8/17.9

Horizontal BW(°) 65 65 65

Vertical BW(°) 7 6.5 6

Polarization +45°/-45° +45°/-45° +45°/-45°

Vertical Beam Tilt(°) 4 4 4

Isolation >30 >30 >30

VSWR <1.5:1 <1.5:1 <1.5:1

USLS >15 >16 >16

Front to Back Ratio 25 25 25

Size: LxWxD(inch/mm) 54.4x6.8x3.5 /1381x172x88

Wind Load (lbf/N) 101/449

Connector Type 7/16 DIN-Female

Connector Location Bottom

2) 360° omni antenna

Kathrein UBO-1940N

Frequency range 1710–2170 MHz (broadband)

Gain 2 dBi

Impedance 50 ohms

VSWR < 1.5:1

Polarization Vertical

Maximum input power 50 watts (at 50°C)

H-plane beamwidth Omni

E-plane beamwidth 78°

Connector N female

Weight 0.33 lb (150 g)

Height 4.55 inches (115 mm)

Radome diameter 0.78 inches (20 mm)

Mounting Mounts through a 0.63 inch

The value of outdoor antenna parameter should also note the hanging height of

antenna. When the parameter of receiver and transmitter is fixed, the height and

gain of coverage area are in direct ratio. Note whether the installation mode of

antenna is tower installation mode or the installation mode of installation pole.


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2. Take the antennae of Tongyu Communication Equipment of Zhongshan for

example to introduce the parameter value of omni antennae.

Tongyu Communication Equipment of Zhongshan, TQI-4FE

824–2500 MHz

Gain 3 dBi

Impedance 50 ohms

VSWR < 1.4:1

Maximum input power 50 watts (at 50°C)

H-plane beamwidth Omni

E-plane beamwidth 70°

Connector N female

Weight 500g

Height 85 mm

Note

The parameters such as radiation mode (antenna pattern), gain, impedance, VSWR, and

polarization mode are important parameters that indicate the antenna performance of

communication system. The ‘Industry standard of communication antenna’ defines

various parameter value ranges. Generally the performance of antenna provided in the

market is better than the industry standard.

7.26 Antenna Model Selection

Knowledge Point

This chapter introduces the classification of the scenarios where the BS antennae are

applied, the principle of the antenna model selection, and the antenna model selection

for different environments.


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7.27 Classification of Antenna Application Scenario s

7.27.1 High-density Urban Areas

7.27.2 General Areas (Cities and Towns)

7.27.3 Suburb (Township) and Countryside

7.27.4 Railways and Express Highways (Highways)


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7.27.5 Scenery Spots

7.28 Antenna Model Selection

7.28.1 Basic Principles of Antenna Model Selection

1. Must select the antenna qualified and approved by the third party, the product

must comply with the standards stipulated by the Ministry of Information

Industry.

Implement environmental experiments such as the environments of high

temperature, low temperature, vibration, impact and transportation.

2. The VSWR and the 3rd order inter-modulation of the antenna must be tested and

100% approved.

3. For WCDMA wireless system, the working frequency band of the selected

antenna should include the frequency band required by the protocol: the uplink

frequency 1920 to 1980 and the downlink frequency 2110 to 2170.

The width band selection should be subject to satisfying the demand.4. Select

shaped-beam antenna (upper side lobe suppression and lower side lobe null

fill-in) to eliminate the interference from other BSs and to avoid the problem of

“light shadow”.

4. Select the electronic downtilt antenna for the high-density areas and the areas

with complicated environment.

5. Select 65° directional ±45° dual-polarization antenna for the urban areas.

6. Select 65° directional ±45° dual-polarization antenna for the highways.


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7.28.2 High-density Urban Areas

7.28.2.1 Areas with Dense Traffic

In the high-density areas of the metropolitans such as Beijing and Shanghai, the

coverage areas cover luxury commercial centers and deluxe offices. The coverage

radius of each BS is relatively small because the numbers of BSs are located at the

same area. In addition, there are lots of indoor coverage systems in the coverage area,

and it is very difficult to select the sites to deploy the BSs because of the fluctuation of

the BSs in the high-density urban areas. The chance to adjust RF system is quite

frequent because the radio environment of the high-density urban area is extremely

complicated. For the above-mentioned reasons, the coverage radius of the BS in the

urban area must be restrained. A larger downtilt angle is needed to eliminate the

interference to the adjacent cells. The antenna beam will be distorted if using the

antenna with a too large mechanical angle. It is very inconvenient for the optimization

because it is even more difficult to control the radio signal. So the antenna with

electronic downtilt must be applied.

The distance between the BSs is about 300 to 500 meters in the high-density areas with

dense traffic. We should select the antenna with adjustable electronic downtilt or the

antenna with fixed electronic downtilt over 6°.

Take the following types of antennae for example:

Internal Model

of Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi

)

Angle (°C) Horizontal

Lobe

AP15-1940/065

D/ADT/XP ± 45° Diversity Panel 1710-2170 15 Adjustable 65

UMWD-06513-

XD ± 45° Diversity Panel

1900 -

2170 12.4/14.5 0-14 63

UMWD-06516A

-XD ± 45° Diversity Panel

1900 -

2170 15.7/17.8 0—10 63

UXM-1710-2100

-65-15i-A-D ± 45° Diversity Panel 1710-2170 15 0 – 16 65

MB3G-65-15.5D ± 45° Diversity Panel 1920-2170 15.5 0-8 65/10.5°

When installing the antenna, the fixing component can allow 14° or so of mechanical

downtilt. In practical installation, the main lobe of the antenna will be distorted if it tilts

over 10° mechanically, therefore, the mechanical downtilt should not exceed 10°. The


187187187187

horizontal half-power width will not be distorted when the main lobe tilts at the range

between 10° to 20° if the electronic downtilt works with the mechanical downtilt.

Therefore, the need to control the coverage radius in the areas with dense traffic can be

met in this way.

7.28.2.2 Areas With Moderate Traffic

For the provincial capitals or the secondary central areas of the metropolitans such as

Beijing and Shanghai, the coverage areas cover plenty of commercial centers and some

luxury houses. The distance between the BSs is about 500 to 700 meters. The BSs are

also in dense condition with a small coverage radius. The antenna with an internal

electronic downtilt of 4° to 6° and horizontal half-power lobe width in 65° direction

must be applied to restrain the interference with the adjacent sectors. In this way, the

horizontal half-power width will not be distorted when the main lobe tilts at the range

between 6° to 16°, and the areas with moderate traffic can be covered without

interference.


Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe

UMWD-06516-6D

± 45°

Diversity

Panel

1900 -

2170 15.5/17.6 6 65

UMWD-06516-6D

Vertical

Polarization

Panel

1900 -

2170 15.9/18 4 65

UXM1710-2100-65-15.5i-6-D

± 45°

Diversity

Panel

1710-2170 15 6 65

7.28.2.3 Areas with Relatively Sparse Traffic

For the areas with well-planned residential apartments and some commercial buildings,

the distance between the BSs can be as wide as 700 to 900 meters or so. The horizontal

half-power width will not be distorted when the main lobe tilts at the range between 2°

to 4° if the antenna is applied with an internal electronic downtilt of 2° to 4° and

horizontal half-power lobe width in 65° direction, and the areas with sparse traffic can

be covered without interference.


188188188188


Internal Model of

Manufacturer Type

Frequency

Range (MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe

UMWD-06517-2D ±45° Diversity

Panel 1900–2170 16.9/19 2 63


Panel 1900–2170 16.6/18.7 4 63

UMWD-06516-2D

Vertical

Polarization

Panel

1900–2170 16/18.1 2 65

AP18-1940/065D/DT

2/XP

±45° Diversity

Panel 1710-2170 18 2 65

UXM-1710-2100-65-

18i-2-D

±45° Diversity

Panel 1710-2170 18 2 65

7.28.3 General Urban Areas

For those general urban areas with residential districts as the main body, such as the

well-planned commercial apartments, the living zones of the enterprises and

governmental sections, and the ordinary residence, there may be some low bungalows

and old-fashion two-storey buildings in such areas. The traffic in those areas is

relatively small. In addition, the radio environment of the coverage area is considerable

good because the buildings there are low. The coverage in such areas is the top priority.

The distance between the BSs ranged within 1 km to 2 km. The single-polarized space

diversity or dual-polarization antenna, such as the considerably high-gain 65°

directional antenna can be applied. At the edge of the network, the 11 dB 90°

directional antenna may be applied.


Internal Model of

Manufacturer Type

Frequency

Range (MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe

742-186 ±45° Diversity

Panel 1710-2170 20.2 0 63


Panel 1900 - 2170 16/18.1 0 65


Panel 1900 - 2170 17.2/19.3 0 63

UXM-1710-2100-6

5-15.5i-0-D

± 45° Diversity

Panel 1710-2170 15 0 65


189189189189

Internal Model of

Manufacturer Type

Frequency

Range (MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe

UXM-1710-2100-6

5-18i-0-D

± 45° Diversity

Panel 1710-2170 18 0 65

MB3G-65-13 Vertical

Polarization 1920-2170 13 0 65/14°

AP12-1940/088D/

XP

± 45° Diversity

Panel 1710-2170 11.7 0 88

UMW-09015-0D Vertical

Polarization 1900 - 2170 14.8/16.9 0 90

7.28.4 Suburb, Twonships, and Countryside

In the case of small traffic, the concern is large coverage. The radio environment is

great because the BSs are considerably in high position in comparison with the low

buildings in the coverage area.

If possible, always select the 65° directional antenna for the coverage area with a clear

direction. Usually select the same antenna as that of the general urban area.

If possible, always select 90 degrees high-gain antenna for the coverage area with a

certain degree of direction, such areas usually have very big coverage and have some

traffic.

For the coverage area without a clear direction and with a relatively big coverage, the

high-gain omni antenna should be applied. In order not to run into the problem of

“darkness under a light” due to the fact that the antenna has been deployed at a too

high position, select the omni antenna with 3°, 5°, and 7° main beam downtilt

according to the height of the BS.


Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe

UBO-1940N

Vertical

Polarization 1710-2170 2 0 360

MB3G-OA-11 Vertical

Polarization 1920-2170 11 3 360


190190190190

7.28.5 Railways and Express Highways (Highways)

7.28.5.1 Highways in Plain or Grassland

For the highways (express highways) on plain or grassland, the coverage radius of a

BS at a height of 50 meters covers 5 km to 8 km or even larger because such areas are

always flat and wide.

If just consider the seamless cover of the highway, the high-gain antenna with

relatively narrow horizontal and vertical beam lobe should be selected, for example:

Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi) Angle (°C)

Horizontal

Lobe

UMWD-03319-2

D

±45° Diversity

Panel 1900-2170 18.2/20.3 2 30

AP21-1940/030D

/ADT/XP

±45° Diversity

Panel 1710-2170 20.7 Adjustable 30

If the coverage area not only covers the highways but also other areas, the 65°, 90°, or

360° antennae should be selected according to the practical requirement.

Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizonta

l Lobe

742-186 ± 45° Diversity

Panel 1710-2170 20.2 0 63

UMWD-06516-0

D

± 45° Diversity

Panel 1900 - 2170 16/18.1 0 65

AP12-1940/088D/

XP

± 45° Diversity

Panel 1710-2170 11.7 0 88


Polarization 1900 - 2170 14.8/16.9 0 90

UBO-1940N ´Vertical


MB3G-OA-11 ´Vertical

Polarization 1920-2170 11 3 360

7.28.5.2 Highways in Hilly or Mountainous Areas

The highways and the express highways in the hilly and mountainous areas always

wind their ways across the valleys. The traffic is very small, but the radio signal

multi-path and attenuation are serious because the highways are often shielded by the

mountains close by. The coverage radius of the BS is about 3 km to 5 km, or even


191191191191

smaller. To get a better coverage in such a radio environment, the high-gain antenna

with narrow horizontal beamwidth is a good choice because the electromagnetic energy

is more concentrative.

Internal Model of

Manufacturer Type

Frequency

Range (MHz)

Gain


Horizontal

Lobe

800-10251 ± 45° Diversity


AP21-1940/030D/A

DT/XP

± 45° Diversity


UMWD-03319-2D ± 45° Diversity

Panel 1900 - 2170 18.2/20.3 2 31

DB992HG28N-B Vertical

Polarization 2170 - 2490 14.9/17 0 25

742-186 ± 45° Diversity

Panel 1710-2170 20.2 0 63


Panel 1900 - 2170 16/18.1 0 65


Panel 1900 - 2170 17.2/19.3 0 63

UXM-1710-2100-6

5-15.5i-0-D

± 45° Diversity

Panel 1710-2170 15 0 65

7.28.5.3 Highways across Cities or Towns

For the coverage areas cover railways/highways and countryside and towns with small

traffic, the omni antenna or the antenna with large horizontal lobe angle should be

applied to achieve the best result.

Internal Model of

Manufacturer Type

Frequency

Range (MHz)

Gain


Horizontal

Lobe

AP12-1940/088D/XP ±45° Diversity

Panel 1710-2170 11.7 0 88


Polarization 1900 – 2170 14.8/16.9 0 90

UBO-1940N Vertical


MB3G-OA-11 Vertical

Polarization 1920-2170 11 3 360


192192192192

7.28.5.4 Mountain Highways

The antenna should be selected according to terrain, objects, the changes of the height

of the mountains, the BS location and the coverage radius.

Generally speaking, the following antennae should be selected prior to the others if the

BS is located at the peak of the mountain:

Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizonta

l Lobe

UMWD-06516-6D

±45° Diversity

Panel ±45°

Diversity Panel

1900 –

2170 15.5/17.6 6 65

UXM1710-2100-65-1

5.5i-6-D

±45° Diversity

Panel 1710-2170 15 6 65

UMWD-09016-XD ±45° Diversity

Panel

1900 –

2170 15.5/17.6 0-5 90


Panel

1900 –

2170 12.8/14.9 6 90

7.28.6 Scenery Spots

7.28.6.1 Scenery Spots Far away from Cities

The natural scenery spots such as famous mountains and beautiful rivers are far way

from the hustle and bustle of the cities. The radio signal in the scenery spot will not

intermix with those of the cities because they have been separated geographically.

Visits to such scenery spots are obviously seasonal. In addition, the visitors usually

gather at certain spots.

There are no restraint to the height of the antenna in such scenery spots. If the traffic is

not so huge, we usually select the control point of the scenery spot as the location of

the machine room and apply omni antenna.

Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe

UBO-1940N Vertical


MB3G-OA-11 Vertical

Polarization 1920-2170 11 3 360

For those popular scenery spots with considerable large traffic, we must utilize the


193193193193

mountain body or other natural objects for separation and apply layered coverage

solutions. In those cases, the low gain antenna with small horizontal beamwidth, which

is easy to be controlled, should be selected.

Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe

DB992HG28N-B Flat Panel 1710 - 2170 13.9/16 0 30

AP12-1940/065/DT2/XP ±45° Diversity

Panel 1710-2170 12 2 65


Panel 1900 - 2170 13.8/15.9 0 90

7.28.6.2 Scenery Spots in Suburban Areas

The signal in the scenery spots at suburban areas will overlay the signal from the BSs

in the urban areas easily because those spots are close to the urban areas. Therefore, the

height of the BS must be restrained strictly in order not to interfere with the BSs in the

urban areas.

Internal Model of

Manufacturer Type

Frequency

Range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizontal

Lobe


Panel 1900-2170 16.9/19 2 63


Panel 1900-2170 16.6/18.7 4 63

UMW-06516-2D Panel Vertical

Polarization 1900-2170 16/18.1 2 65

AP18-1940/065D/DT2

/XP

±45° Diversity

Panel 1710-2170 18 2 65

UXM-1710-2100-65-1

8i-2-D

±45° Diversity

Panel 1710-2170 18 2 65

7.28.6.3 Scenery Spots in Downtown Areas

Those scenery spots in downtown areas have very high humanistic value and cannot be

counted in money. The indoor distributed systems cannot be applied for the safety of

the scenery spots. The sole solution is to set up BSs closely and utilize the outdoor

signal for indoor coverage. In addition, it will greatly influence the radio network of

the entire city because those scenery spots are located in the downtown areas of the


194194194194

cities. Therefore, the high-gain antenna with narrow horizontal lobe angle and wide

vertical lobe angle is a favorable choice for such scenery spots.

Internal Model of

Manufacturer Type

Frequency

range

(MHz)

Gain

(dBd/dBi)

Angle

(°C)

Horizonta

l Lobe

800-10251 ±45° Diversity


AP21-1940/030D/AD

T/XP

±45° Diversity



Panel 1900-2170 18.2/20.3 2 31

DB992HG28N-B

Vertical

polarization

Flat Panel

2170-2490 14.9/17 0 25

742-186 ±45° Diversity

Panel 1710-2170 20.2 0 63


Panel 1900-2170 16/18.1 0 65


Panel 1900-2170 17.2/19.3 0 63

UXM-1710-2100-65-

15.5i-0-D

±45° Diversity

Panel 1710-2170 15 0 65

7.29 Type Library of WCDMA Antennae

7.29.1 Collection of WCDMA Outdoor Omni Antennae

1. Code: (To Be Determined) Antenna Manufacturer: KATHREIN

Product Number: HXS-201-60-1.9-6-2GHz-60

Electrical Specifications

Frequency Range 1920 MHz ~ 2170 MHZ

Gain 11.6 dBi

Horizontal 3dB Beamwidth 360°

Vertical 3dB Beamwidth 6-8°



195195195195

Impedance 50 Ω

VSWR < 1.54

Maximum Input Power 100 W

Connector 7/16NID-F

IM.3rdOrder(2 × 43dBm) <-150dBc

Lightning Protection Direct Ground

Mechanical Specifications

Dimensions (D × L) φ 60 × 1500 mm

Weight of Antenna 3.8kg

Weight of Mounting Kits 1.3kg

Diameter of Installation Pole φ 50 mm ~ 110 mm

Radome Material Fiberglass

Rated Wind Velocity 241 km/h

2. Code (To Be Determined) Antenna Manufacturer: GCI Science & Technology

Product Number: TQJ-2000-11-3G


Frequency Range 1920 MHz ~ 2170MHZ

Gain 11 dBi


Vertical 3dB Beamwidth 6-8°


Impedance 50Ω

VSWR < 1.5


Connector 7/16NID-F

IM.3rdOrder (2 × 43 dBm) < -150dBc


196196196196

Lightning Protection Direct Ground


Dimensions (D × L) φ 60 × 1500 mm


Weight of Mounting Kits 1.3kg

Diameter of Installation Pole φ 50 mm ~ 110 mm



3. Code (To Be Determined) Antenna Manufacturer: Mobile Antenna Technologies

(Shenzhen) MB3G-0A-11

Product Number: DB909E-U



Gain 11 dBi


Vertical 3dB Beamwidth 8°

Main beam angle 0 ~ 1.5°


Impedance 50 Ω

VSWR < 1.4


IM.3rdOrder (2 × 43dBm) < -150dBc

Connector 7/16NID-F


Dimensions of antenna (D × L) φ 58 × 1870mm



197197197197

Diameter of Installation Pole φ 50 mm ~110mm


Rated Wind Velocity 45m/s

Color White

4. Code (To Be Determined) Antenna Manufacturer: ANDREW

Product Number: DB909E-U



Gain 11 dBi


Vertical 3dB Beamwidth 7°


Impedance 50 Ω

VSWR < 1.5


IM.3rdOrder (2 × 43dBm) < -150dBc

Connector 7/16NID-F

Lightning Protection DC grounding


Dimensions (D × L) φ 50.8 × 1397 mm

Weight of Antenna 1.6 kg

Diameter of Installation Pole φ 50 mm ~110 mm



Color Light grey


198198198198

7.29.2 Collection of WCDMA Outdoor Directional Ante nnae

1. Code: 53140085 Antenna Manufacturer: KATHREIN

Product Number: UMWD-06516-2DM

Electrical specifications

Frequency Range 1920-2170 MHz

Gain co-polar 17.5 ±0.5dBi

Horizontal 3dB beamwidth 65°

Vertical 3dB beamwidth 6.5°

Front-back ratio > 28dB

Polarization +45°, -45°

Isolation > 30dB

Impedance 50 Ω

Electric downtilt > 12°

VSWR < 1.5

Maximum input power 300W

Connector 2 × 7/16NID-F

Mechanical specifications

Dimensions 1371 × 177 × 88mm

Wind load 101/499(lbf/N)

2. Code: 53140085 Antenna Manufacturer: Celwave (Shenzhen Centurydragon as

Agency)

Product Number: Apx206515(Celwave)



Gain co-polar 17.7dBi

Horizontal 3dB beamwidth 65°±3°

Vertical 3dB beamwidth >6°


199199199199

Front-back ratio >28dB


Isolation >30dB

Impedance 50 Ω

VSWR < 1.5


Connector 2 × 7/16NID - F

IM.3rd order (2 × 43dBm) < -160dBc

Lightning protection DC grounding


Dimensions (L × W × H) 1360 mm × 169 mm × 80 mm

Weight of antenn 8.0kg

Diameter of installation pole φ 50~110 mm

Radome material UV Resistant Fibre Glass

Rated wind speed 55.6m/s

3. Code: 53140085 Antenna Manufacturer: KATHREIN (Qiancheng Technologies

as Agency)

Product Number: TDJS-2000-18-H65-3G


Frequency Range 1920 ~ 2170 MHz

Gain co-polar 18 dBi

Horizontal 3 dB beamwidth 65°

Vertical 3 dB beamwidth 7°

Front-back ratio > 25 dB


Cross-polar discrimination >20dB


200200200200

Isolation > 28dB

Impedance 50 Ω

VSWR < 1.5


Connector 2 × 7/16NID - F

IM.3rd order (2x43dBm) <-150dBc

Lightning protection DC grounding


Dimensions (L × W × H) 1300 mm × 160 mm × 75 mm

Weight of antenna 4.5 kg

Weight of mounting kits 3.5 kg

Diameter of installation pole φ 50 ~ 110 mm

Radome material UPVC

Horizontal 360°

Angle of pitch 0 ~ -15°

Rated wind speed 241 Km/h

7.29.3 Collection of WCDMA Indoor Omni Antennae

1. Code: 53140182 Antenna Manufacturer: GCI

Science & Technology

Product Number: TDJ-DF

Technical Specifications:

Frequency Range 824-960&1700-2200 MHz

Gain 3 dBi

Input power 50 W

Nominal Impedance 50Ω



201201201201

VSWR < 1.5

Connection mode

Standard Termination N-50F

Height (mm) high (mm) 62

Diameter 200 mm

Weight 500 g

2. Code: 53140128 Antenna Manufacturer: Mobile Antenna Technologies

(Shenzhen)

Product Number: MB5F-0A-3/5-C


Frequency Range (MHz) 800-2400

Gain (dBi) 3(824-960MHz)

5(1710-2170MHz)

VSWR < 1.4


Impedance (Ω) 50

Connection Type N(F)


Radiating Element Material Copper

Radome material ABS

Radome Color White

Dimensions of antenna

Dimension(mm) φ 160 × 85

Packing Size(mm) 180 × 180 × 155

Weight (Kg) 0.4

Operating Temperature(°C) -40 ~ +70


202202202202

Reposition Temperature(°C) -55 ~ +50

3. Code: 53140128 Antenna Manufacturer: Shenglu Antenna of Sanshui

Product Number: TQJ-SA800/2200-3

Technical Specifications:

Frequency Range 806-960&1710-2170 MHz

Gain 3 dBi

Input power 50 W

Nominal Impedance 50 Ω


VSWR < 1.5

Connection mode Standard Termination N-50F

Material Ultraviolet radiation protection ABS

Dimensions 168 × 80 mm

Weight 490 g

7.29.4 Collection of WCDMA Indoor Directional Anten nae

1. Code: 53140126 Antenna Manufacturer: GCI Science & Technology

Product Number: TDG - 2000-9-H65-3G



Gain 9 dBi

Horizontal 3dB beamwidth 62°±5°

Vertical 3dB beamwidth 46° ±5°

Front-back ratio > 15dB


Impedance 50 Ω

VSWR < 1.5


203203203203

Input power 50 W

Connector N-F

IM.3rd order <-150dBc


Dimensions of antenna 220mm × 173mm × 44mm


Radome material Fire-resistant ABS

2. Code: 53140126 Antenna Manufacturer: Mobile Antenna Technologies

(Shenzhen)

Product Number: MB5F-70/40-9/6-W


Frequency Range(MHz) 824-2200

Gain (dBi) 9(824-960MHz)

6((1710-2170MHz)

VSWR < 1.4

Horizontal-3dB Beamwith 70(824-960MHz)

40 (1710-2170MHz)

Polarzation Vertical

Impedance (Ω) 50

Connection Type N(F)


Radiating Element Material Copper

Radome Material ABS

Radome Color White

Dimensions (mm) 240 × 220 × 65

Packing Size (mm) 260 × 270 × 80

Weight (Kg) 1.5


204204204204

Mounting Type Plug-in

Operating Temperature (°C) -40 ~ +70

Reposition Temperature (°C) -55 ~ +50

2. Code: 53140126 Antenna Manufacturer: Shenglu Antenna of Sanshui

Product Number: TDG - 2000-9-H65-3G


Frequency Range 824~960MHz 1710-2170 MHz

Gain 7 dBi

Polarization Linear polorization

Impedance 50 Ω

VSWR < 1.7

Input power 50 W

Connector N - F

IM.3rd order (2 × 43dBm) <-150dBc


Dimensions of antenna 210mm × 180mm × 44mm


Radome material Ultraviolet radiation protection ABS

7.30 Antenna Installation Specifications

Knowledge Point

This chapter introduces the installation and debugging methods for BS antenna, as well

as points for attention.

7.31 Antenna Installation

Antenna installation is of two types, pole installation and tower installation. Pole

installation is to install the antenna on the top of buildings or walls in the streets in


205205205205

urban areas. Please note the two installation modes.

7.31.1 Pole Installation

1. Pole is the basis to install antennae. Whether the pole is vertical or not

influences the adjustment of antenna direction and angle.

The inclined pole due to problems in pole itself or installation directly affects the

declination angle accuracy of the directional antenna and the receiving effects of

the omni antenna. Therefore, the very first thing is to ensure the pole for

installing antenna is straight. Plumb could be applied to make sure the antenna is

vertical to the ground. The declination angle of the directional antenna should be

measured by the inclination tester. Mechanical inclination should include pole

engineering inclination and bending.

Whether the pole is straight is vital to the network performance in planning and

optimization. However, checking the straightness of the antenna installation is

usually neglected.

2. The antenna is always installed 10cm above the top of the pole to firmly fix the

antenna onto the pole. The anchor ear around the antenna does not fall off, the

inclination could be adjusted easily, and the electric discharge is running

normally.

7.31.2 Tower Installation Mode

In actual installation, when using the boom whose distance away from the tower

platform is longer than 1M to set the antenna, the vertical separation between different

platform is 1M.

In general, please note the following when installing antenna on the tower:

1. Installation at the directional antenna tower: To reduce the influence by the

antenna tower to the antenna pattern, the maximum directivity outside the tower

can be obtained when the distance from the center of the antenna to the tower is

λ/4 or 3λ/4.

2. Installation at the omni antenna tower: To reduce the influence by the antenna

tower to the antenna pattern, the antenna tower must not be taken as the reflector

for the antenna. Thus, the antenna should be installed on the edge angle, and the

minimum distance from the antenna to any part of the tower is bigger than λ.


206206206206

3 Multi-antenna on the same tower: To reduce the coupling effects and

interactions of receiving and transmitting antenna from different networks, and

enlarge the isolation between each antenna, the best solution is to enlarge the

distance between each antenna. Vertical installation should be employed when

multi-antenna share the same tower.

7.32 BS Antenna Structure and Connection

Take a 3-sector BS for example to describe the installation procedures of the BS

antenna system.

1. Amount of related components:

1) Six patches of BS antennae

2) If the system configuration includes tower amplifier, then six tower amplifiers

are needed.

3) Jumpers from the antenna to the main feeder. Appropriate length should be

chosen. Six jumpers are needed.

4) Main feeder

5) Lightning arrester. Every feeder should be equipped with one lightning arrester.

Six lightning arresters are needed.

6) Jumpers from the main feeder to the cabinet. Appropriate length should be

chosen. Six jumpers are needed.

2. There is one feeder connecting each set of BS antenna to the cabinet top. For

configurations without tower amplifiers, from the antenna to the cabinet, each

feeder includes the following:

1) 1/2 super flexible jumper from the antenna to the main feeder (If there is the

tower amplifier, this jumper is the one that goes from the antenna to the tower

amplifier, then to the main feeder. The connectors are male DIN connectors.

2) The main feeder is a 7/8 feeder, with a length from several meters to hundreds of

meters. The connectors for jumpers between the antenna and the main feeder

and those between the main feeder and the cabinet top are female DIN

connectors.


207207207207

3) There is a lightning arrester between the main feeder and jumpers on the cabinet

top. The lightning arrester should be connected to ground. The connectors are

DIN connectors, with the male connectors connecting the main feeder, and the

female connectors connecting the jumpers.

4) The jumper between the main feeder and the cabinet top is the 1/2 super flexible

jumper. The connectors are male DIN connectors.

5) Before the feeder goes into the equipment room, the grounding kits should be

installed onto the upper and lower parts of the main feeder. If the feeder is

longer than 60m, grounding kits should be installed in the main feeder.

6) For configurations with tower amplifier, jumpers also include those from the

antenna to the tower amplifier and from the tower amplifier to the main feeder.

3. Many other accessories are also used in the installation of the BS antenna,

including:

1) Outdoor grounding kit (with 7/8” main feeder).

2) Indoor grounding kit (with 7/8” main feeder).

3) Indoor grounding kit (with 1/2” main feeder)

4) Outdoor grounding window (12 or 22 holes)

5) Triple feeder fixing card (with 7/8” main feeder)

6) Feeder feeds through (with 7/8” main feeder).

7) Indoor grounding copper busbar (with 7/8” main feeder).

8) Indoor cable rack and its accessories

For the connection of the BS antenna system, please refer to Fig. 7.32-1.


208208208208

Fig. 7.32-1 Installation of the BS Antenna System

7.33 BS Antenna Installation

7.33.1 Considerations

1. To ensure safety for the BS equipment, the following requirements should be

fulfilled:

1) The tower in the BS is fixed on the ground. The feeder should be grounded well

on the platform of the tower top, between 0.5 and 1 m above the point where the

feeder bends away from the tower, and outside the entrance to the equipment

room. The center of the feeder should be grounded when it is longer than

60m.The metal sheath of the feeder is connected to the grounding copper busbar

through grounding kit. Connect a tin-plated copper line or hot zinc-plated flat

steel whose cross-sectional area is no less than 95m2 from the busbar to the

corresponding reserved hole in the tower.


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2) Install the antenna with pole. Each pole should be connected to the lightning

arrester area. Anticorrosion preparations should be done for the grounding

connections.

3) The main feeder should be strengthened every 1.2m, while the bends should be

further enhanced when necessary. After the installation of the feeders, the holes

for feeders to enter the equipment room should be sealed up well in order to

prevent rain water from seeping into the equipment room.

4) The antennas, feeders, tower, and equipment in the equipment room should all

be grounded well. The working grounding of each BS should form a combined

grounding system with the grounding resistance less than 1 Ω.Feeders should be

grounded respectively at the connections to the antenna, bends away from the

tower, and outside the entrance to the equipment room; and one more time after

entering the equipment room.

2. System requirements of the antenna installation:

1) Isolation between each antenna. The isolation should be at least larger than 30dB

between two transmitting antennas, and between the transmitting and the

receiving antenna.

2) To achieve a certain diversity gain, diversity distance should be implemented to

the receiving antennas.

3) There should not be no serious distortion to the antenna pattern due to

reflections of the obstacles and barriers around the antenna.

4) Multi-antenna on the same tower: To reduce the coupling effects and

interactions of receiving and transmitting antenna from different networks, and

enlarge the isolation between each antenna, the best solution is to enlarge the

distance between each antenna. Vertical installation should be employed when

multi-antenna share the same tower.

7.33.2 Outdoor Directional Antenna Installation

Installation procedure for installing the BS antenna:

1. Following the order in Figure 4.2 (a), (b), respectively install the antenna

declination angle fixed racks to corresponding positions on the antenna. Frap the

racks to make them folded.


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2. Make sure the input/output ports of the antenna are facing downwards. Adjust

the antenna to the right height. Fix the antenna declination angle fixed racks to

the antenna pole with the screw bolt and U bolt.

3. Use the compass to figure out the differential angle between the direction of the

antenna radiant surface and the north, and also the south. Work out the angle

between adjacent antenna radiant directions according to the differential angle of

the antennas in adjacent sectors. Turn the antenna around the pole to adjust the

angle between adjacent antennas as required.

The angle between antennas in different sectors for deployment is 120°.The

antennas in the same sector should point to the same direction.

4. Use the antenna declination angle fixed racks to adjust the antenna angle of

direction, and adjust the antenna declination angle to the right position. The

antenna declination angle should be as same as the indications on the antenna

declination angle fixed racks. The errors should not exceed ±1°.

5. Fix the screws in Fig. 7.33-1(a), (b) with the spanner.

(a) (b)

Fig. 7.33-1


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Note: To reduce the influence by the antenna tower to the antenna pattern, the

maximum directivity outside the tower can be obtained when the distance from the

center of the antenna to the tower is λ/4 or 3λ/4.

7.33.3 Outdoor Omni Antenna Installation

The installation of the omni antenna is simpler. As long as the verticality could be

ensured and it is firmly installed, it will be fine. Other steps are as the same as those for

the directional antenna, as shown in Fig. 7.33-2 (1), (2).

Fig. 7.33-2 Outdoor Omni Antenna Installation

Note: To reduce the influence by the antenna tower to the antenna pattern, the antenna

tower must not be taken as the reflector for the antenna. Thus, the antenna should be

installed on the edge angle, and the minimum distance from the antenna to any part of

the tower is bigger than λ.

7.33.4 Indoor Antenna Installation

1. Take the MB5F-0A-3/5-C of Mobile Antenna Technologies (Shenzhen) for


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example to illustrate the installation procedures for omni ceiling-mount indoor

antenna.

1) Find out the position on the ceiling to install the antenna, and drill a hole with

the diameter as 17~18mm with the electrical drill.

2) Open the antenna packing. Take off the cab of the cable connector and loosen

the chuck. Insert the cable connector into the hole in the ceiling and put it

through. Spin the chuck into the cable connector and fix it. Screw up the cable

connectors of the BS with the antenna cable connector, as shown in Fig. 7.33-3

(1), (2), and (3):

Fig. 7.33-3 Omni Ceiling-Mount Indoor Antenna Installation (1)

2. Take the TDG-2000-9-H65-3G of GCI Science & Technology for example to

illustrate the installation procedures for directional wall-mount indoor antenna.

As shown in Fig. 7.33-4, fix the support plate into the wall with three wood

screws, then insert the antenna into the support plate as illustrated in the figure.

(If a pitch angle is needed, bend the support plate correspondingly) Connect a 50

Ω coaxial cable.


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3-M4x8

screw

Wall

Wall-mount

antenna

Support

plate

Fig. 7.33-4 Directional Wall-Mount Indoor Antenna Installation

7.33.5 Jumper Installation

7.33.5.1 Principle

The installation of the feeder system for the BS antenna requires jumpers from

receiving/transmitting antenna to the main feeder and from the cabinet top to the main

feeder. If the antenna feeder system is configured with tower amplifier, there will be

more jumpers needed. The number of jumpers includes connection jumpers from the

antenna to the tower amplifier and jumpers from the tower amplifier to the main feeder,

as shown in Fig. 7.33-5:

Fig. 7.33-5 Jumper Installation1/2”

7.33.5.2 Installation Procedure

1. Choose an appropriate jumper route. Consider reliability and convenience and

try to make it as short as possible. Choose appropriate length for the jumper.

2. Connect the connectors of the antenna and the jumper based on appropriate


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moment, and make sure there is no side stress on the connectors of the antenna

and jumper.

3. Connect the connectors of the main feeder and the jumper based on appropriate

moment, and make sure there is no side stress on the connectors of the main

feeder and jumper.

4. Fix the jumper with the hanger in a distance of no longer than 0.76m.

5. Seal the connectors with 3M single-coated foam and PVC adhesive tape upon

correct measure of the antenna and feeder.

7.33.5.3 Precautions

Note the following when installing 1/2 super flexible jumper to avoid influence of the

reliability of the BS antenna system.

1. The minimum bending radius is 32mm for one-time bending.

2. The minimum bending radius is 32mm for repetitive bending. At least it could

be bent 20 times. The nominal value is 50 times.

3. The maximum pulling force is 80KGk, the maximum bending moment 2.7NM,

and the maximum impact strength 1.8KG/M.

4. The maximum hanger separation is 0.76m.

7.33.6 Lightning Arrester Installation

7.33.6.1 Principles

All the cables led by the antenna to the equipment room must be connected in parallel

with a lightning arrester to the grounding cable, thus when the over-voltage wave

created by the landed lightning in distance attacks the system along the cables, the

lightning arrester can divert the over-voltage wave to the ground and jam all the

channels to prevent lightning current attack.

λ/4 stub tuner is a type of typical lightning arrester instrument. It is similar to the

parallel connection of an infinite impedance. Its great attenuation to the lightning

enables the destructive energy to be diverted to the ground while there is no impact on

the equipment, as shown in Fig. 7.33-6.


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Fig. 7.33-6 Lightning Arrester


1. The lightning arrester is usually installed between the 7/8” main feeder and the 1/2”

cabinet top jumper after the main feeder enters the equipment room. There are

two DIN connectors for the lightning arrestor, with the connectors on both sides

being female.

2 Check whether the working frequency of the lightning arrester is the same as

that of the BS system. The frequency is indicated on the lightning arrester.

3. The grounding post of the lightning arrester should be connected to the main

grounding post or system grounding cable loop to ensure the impedance to the

ground is as small as possible.

4. Do not seal the connectors before the feeder performance test. Seal them with

single-coated foam upon correct installation and test.

7.33.6.3 Precautions

1. There are two Radio Frequency (RF) ports. Each RF port can be connected to

either the antenna or the BS. The same lightning protection is provided by the

lightning arrester. However, the RF port cannot be exposed outdoor for any use.

2. The grounding post of the lightning arrester should be connected to the main

grounding post or system grounding cable loop to ensure the impedance to the


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ground is as small as possible.

3. In installation, all the grounding contact surface should be clean, dry and

inoxidized.

7.33.7 Grounding kit Installation

7.33.7.1 Principle

The grounding kit is used for connecting conductors outside the feeder and tower frame

or separated conducting wire post to provide channels for current to the ground in case

of thunder and lightning. Usually, the grounding kits should be installed at the top of

the feeder near the BS antenna, at the vertical part of the feeder end, and before the

feeder entering the equipment room. For feeders longer than 60m, the center of the

feeder should be connected with grounding kits, as shown in Fig. 7.33-7.

Fig. 7.33-7 Grounding kit


1. Connect the fixing piece of the grounding kit and the main feeder:

1) Connect the fixing piece of the grounding kit to the 7/8” feeder. Mark at the

corresponding installation position on the 7/8” feeder. Install the corresponding

sheath for the 57mm 7/8” feeder.

2) Prepare a section of 38mm water-proof adhesive tape. Wrap the tape on the

grounding cable at Grounding kit B.(See Fig. 7.33-7)

3) Cover the outer conductor of the feeder with the coupling piece for grounding

and tighten fixing piece.


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4) Make sure the fixing piece is over the little bulge on the side of the coupling

piece, and press firmly on the fixing piece of the grounding kit towards the

feeder to let the water-proof adhesive tape take shape.

5) Wrap the whole connection with the water-proof adhesive tape from the lower

part of the connection.

6) Wrap five layers of electrical insulating adhesive tape around the whole

connection in half-lap covering mode, with each layer 25mm higher than the

previous.

2. Connect the grounding end of the grounding kit and the grounding system:

1) When connecting the grounding terminal to the grounding cable, cover the cable

with shrinking bushing and grounding fastener. Press the shrinking bushing.

Heat around the shrinking bushing to improve shrinking effects. The shrinking

bushing cannot be put on flat areas of the grounding terminal.

2) Connect the grounding terminal with the tower body or special grounding post.

Clear up the paint and oxide within a radius of about 13mm around the

connection. Coat the clean area with anti-oxidation cream to ensure good

electrical contact.

Warning

Installation of grounding kits is forbidden in case of thunder storm. Neglect of this

warning may cause harm or even life danger to yourself or others.

7.34 Antenna Feeder System Debugging

7.34.1 Prerequisites

1. Antenna testing aims to check whether the antenna system is installed correctly

and able to run normally. The testing includes antennas, feeders and jumpers.

2. The installation of antennas, feeders and jumpers should be completed. The

antenna and the tower amplifier are disconnected.

3. The test should be well organized. Please avoid repeated connection and

disconnection of connectors and sealing components. Do not seal connectors

before the test finishes.


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7.34.2 Debugging Procedure

1. Check whether the Connect the antenna and the feeder is correct.

2. Check whether the feeder and connectors are damaged, and connectors are

connected correctly.

3. Use the compass to figure out the differential angle between the direction of the

antenna radiant surface and the north. Work out the angle between adjacent

antenna radiant directions according to the differential angle of the antennas in

adjacent sectors. If the network planning requirements are not met, antennas

should be adjusted.

4. Test the feeder insertion loss, measure the antenna feeder reflection coefficient

and the antenna feeder system standing wave ratio (usually less than 1.5). If the

network planning requirements are not met, connections of each connector

should be checked.

7.35 Connector Sealing

Seal the connecting connectors upon a passed test of the antenna feeder system. Two

kinds of adhesive tapes are employed, water-proof adhesive tape and electrical

insulating adhesive tape. First wrap with the water-proof adhesive tape, and then put

electrical insulating adhesive tape over it.

Note

3M Scotch Super33+ electrical insulating adhesive tape is fire-retardant, frost resisting

and corrosion resistant. It is applicable for use under 600V. The temperature should not

exceed 80°C.

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8 WCDMA Radio Network Optimization Process and Technology

Radio network optimization means to improve the coverage, capacity, QoS and

resource utilization of the network through appropriate adjustment of radio

communication network planning and design and to operate the network in a more

reliable and economical way.

8.1 Service Consideration of Network Optimization

We all knows, a wonderful network comes from fluent requirements, deliberate

planning, well-controlled process and continuous optimization.

Coveragecapability

Networkcapacity

Operator's revenue

OperationcostQoS

Fig. 8.1-1 Service Consideration of Network Optimization

8.2 Reasons for Network Optimization

Network optimization is needed when any of the following events occurs:

When the network quality cannot satisfy the planning and design requirements

(mostly at the initial phase of network construction)

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When the network environment changes, for example, the voice and data

subscribers keep increasing to cause deterioration of the existing network

performance or the urban environment keeps changing to cause regional

coverage differences of the network, the network originally designed will be

unable to adapt to the new environment requirements and thus the network will

need to be optimized and adjusted. In this case, suggestions on the subsequent

capacity expansion of the network shall also be put forward.

8.3 Types of Network Optimization

The objectives of network optimization vary with the different phases of UMTS

network construction. By the implementation period, objectives and steps of

optimization, network optimization can be divided into engineering optimization and

O&M optimization.

8.3.1 Engineering Optimization

Engineering optimization refers to the network optimization performed after the

network is constructed but before subscriber numbers are allocated. Its major purpose

is to enable the network to successfully run and ensure the planned network coverage

and interference targets.

Engineering optimization involves the following jobs:

Check the consistency between cell configurations and the network planning

targets

Troubleshoot system hardware faults

Achieve a satisfactory level of coverage and interference

8.3.2 O&M Optimization

O&M optimization is intended to improve the network quality and to enhance the

customer satisfaction by optimization means during the network operation. Firstly, the expectations of O&M Optimiztion are:

1. Improve the network coverage and gradually eliminate coverage blind-spots

2. Improve the system capacity


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3. Improve the QoS of the network

4. Provide more high-quality service for the hot-spots

5. Maximize the return on investment

Secondly and finally, O&M optimization covers the following three jobs:

1) Routine maintenance

Routine maintenance refers to routine alarm information observation,

troubleshooting of hidden faults, handling of subscriber complaints and so on,

which is the fundamental responsibility of the operator.

2) Phased optimization

It aims to improve the network performance, which includes, minimizing

interferences, improving the network capacity and optimizing system parameters

so that the network KPIs will reach a better level.

3) Network operation analysis

It means to analyze the possible equipment troubles or network problems by

periodically extracting and analyzing OMC performance statistics data and to

submit the Operation Analysis Report on the Network in XX Service Area to

provide a reference for adjusting and optimizing the Customer’s network.

8.4 Optimization Workflow

The following figure illustrates the WCDMA radio network optimization flow:

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Start

Network data collection

Data analysis

Does the networkperformance satisfythe requirements?

Optimizationsolution preparation

End

NO

YES^_^

Preparatory work

Optimization projectacceptance

Document archiving

Networkassessment report

Optimization &adjustment plan

Optimization &adjustment records

Networkoptimization report

Frequency spectrum scanning

Calibration test

Optimization effectverification

Emulation/planning report

Optimization solutionimplementation

Optimizationproject plan

Parameter check

Problem location

Note: The steps not mandatory for each network optimization are indicated in red and may be tailored to the specific onsite situation.

Fig. 8.4-1 WCDMA Radio Network Optimization Flow Chart

The network optimization flow covers the following steps: Preparation (optional),


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frequency spectrum scanning (optional), calibration testing (optional), network data

collection, data analysis, parameter checking (optional), problem location, optimization

solution preparation, optimization solution implementation, optimization effect

verification, optimization project acceptance and document archiving.

Note:

The above figure shows the complete network optimization flow and the steps may be

tailored appropriately according to the actual scale of the network, the network

conditions and the Customer’s requirements. If frequency scanning and calibration test

have been done during the planning period, they may be omitted during the

optimization. In addition, parameter check is needed only when it is regarded as

necessary through network data analysis.

8.5 Optimization Steps

8.5.1 Preparation

The following preparatory work should be done before the formal optimization:

1. Requirement analysis

Requirement analysis shall be based on the full and effective communication

with the Customer and the following things shall be confirmed through it:

1) The Customer’s requirements for network optimization targets, including the

specific requirements for the coverage, capacity and QoS of the network

2) The responsibility division interface between us and the Customer

3) The project acceptance time and criteria

2. Work plan formulation

The work plan shall be made on the basis of the specific network scale, human

and equipment resources, the Customer’s requirements for network optimization

targets and other relevant conditions. The Optimization Project Plan for the

WCDMA Radio Network in XX Service Area shall be output for it. The plan

shall cover the staff composition of the network optimization project, the

planned optimization means and the optimization progress schedule.

A complete work plan is the guarantee to smooth deployment of network

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optimization and can be used to monitor the progress of optimization.

3. Data collection and investigation

The following documents and data shall be collected before network optimization:

1) Emulation Report on the WCDMA Radio Network in XXX Service Area and

Planning Report on the WCDMA Radio Network in XX Service Area in the

network planning phase.

2) Planned network site information, antenna feeder information, system parameter

settings and other relevant information.

3) Existing problems of the current network.

4. Preparation of optimization tools

1) The driving test tools are the basic tools for network optimization tests. They

include the driving test software, test UEs, receiver and GPS. Some driving test

devices may also require dual serial port cards.

2) A signaling analyzer may be needed to implement signaling tracing and location.

If interference test is needed, a frequency spectrum meter and other relevant

equipment may need to be prepared. In addition, a compass and other relevant

equipment may be needed if engineering parameters are to be adjusted.

8.5.2 Frequency Spectrum Scanning (Optional)

Scan the frequency currently used by the network in the optimization area with consent

of the Customer, so as to confirm that the frequency is clean and available for use.

8.5.3 Calibration Test (Optional)

The calibration test covers the following test items:

1. Vehicle-mounted antenna calibration test

2. Calibration test of the external antenna of the test UE

3. Average penetration loss test of the vehicle

Conduct the above tests in the static condition. You can use multiple test UEs at

the same time to make call tests inside the car, from the external antenna of the

test UEs to the top of the car and at the normal conversation positions in the


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passages outside the car. Record the receiving power of these UEs and average

them to get the loss of different environments relative to the environment inside

the car.

4. Building penetration loss test

Test the building penetration loss with the same method as described above, and

compare the indoor receiving power with the outdoor receiving power to get the

penetration loss value. In getting the loss value, you should average the

receiving power of multiple test points.

8.5.4 Network Data Collection

The network data needed for optimization generally come from driving test (DT) data,

CQT data, OMC performance measurement data, user complaints, alarm data and other

relevant data.

Because the network assessment data can be compared only in the same load condition

and the same call mode, you must clarify the parameter selection for network data

collection first.

1. Load selection

The load for network assessment test falls into three cases: In the busy hour,

when there is load and when there is no load (or when there is only light load).

1) The busy-hour test refers to the network assessment test done in the busy hour of

the current network. It needs to measure the traffic of each Node B during the

test through the background measurement system. The network assessment data

in different service areas can be compared only in similar load conditions. The

busy-hour test generally applies to networks that have been formally put into

operation for a period of time.

2) The loaded test is used to simulate the network performance when there are

plenty of subscribers in the network by adding simulated loads in the uplink and

the downlink (the simulated load method applies to the engineering optimization

phase). The downlink load adopts the OCNS mode and the uplink load is

implemented by connecting the transmitting end of the UE to the attenuator. The

loaded test can be conducted at a normal time for networks without large-scale

number allocation but can only be conducted at the midnight when there is very

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little traffic for networks that have completed large-scale subscriber number

allocation, so as to accurately simulate the load and reduce the impact of the test

on subscribers in the actual network. In addition, the OCNS mode applied to the

downlink load can only reflect the radio network performance rather than the

processing capability of the system. Preferably the load of the uplink shall be

implemented by connecting a noise simulator to the receiving end of the Node B,

but it is hard to equip all Node Bs with a noise simulator. Therefore, the load of

the uplink shall be implemented by connecting the transmitting end of the UE to

the attenuator.

3) The unloaded (or light load) test is a network assessment test conducted when

there are no subscribers or there are only few subscribers in the network. The

unloaded test can be conducted at a normal time for networks without

large-scale number allocation but can only be conducted at the midnight when

there is very little traffic for networks that have completed large-scale number

allocation, so as to accurately reflect the radio performance of the network,

facilitate the comparison with the loaded test to discover if the problems in the

network are caused by the load, and reduce the impact of the test on subscribers

in the actual network.

The busy-hour test is generally adopted for networks that have completed

large-scale subscriber number allocation and have been formally put into

operation while the unloaded or loaded test is generally adopted for networks

newly constructed.

2. Call mode

By call time, the call mode may fall into continuous long calls and periodic

calls.

1) The continuous long call test means to originate calls for continuous tests in the

coverage area and automatically re-attempt the call if a call drops by setting the

call hold time to the maximum value. This test can be used to test network

performance parameters such as call drop ratio, handover success ratio,

handover cell ratio and data service rate.

2) The periodic call test is used to periodically originate calls to test network

performance by setting the call setup time, the call hold time and the call


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gapping to a group of fixed values. It can better reflect the processing capability

of the system and can be used to test network performance parameters such as

call completion ratio and call drop ratio.

The major difference between the above two call modes lies in the call hold time: The

continuous long call test shall have a call hold time as long as possible while the periodic

call test shall have a fixed hold time (depending on the specific situation).

In addition, the periodic call test relates to more calls and can better reflect the processing

capability of the system. Its test results are more approximate to the actual use situation of

subscribers. In contrast, the continuous long call test can better reflect the handover

performance of the system.

8.5.4.1 Driving Test (DT) Data

The driving test items of the CS domain service include the coverage ratio, call success

ratio, call drop ratio, conversation quality and handover success ratio, whereas those of

the PS domain service include the PDP Context activation success ratio and the average

uplink/downlink transmission rate.

1. The driving test refers to the process of moving in the specified paths in the

coverage area and using driving test equipment to record all test data and

location information.

2. The driving test data shall cover the following information: Pilot Power, Ec/Io,

UE Tx Power, Neighbours, Call Success/Drops, and HandOver statistics,

Service allocation and FER/BLER.

3. The driving test equipment includes the scanner, test UE, test software ZCPOS

CNT1 (UMTS Edition), portable test PC and GPS. Sometimes some auxiliary

equipment such as the USB expander, vehicle-mounted power inverter and

terminal plate may be needed. The signal receiver and test UE among the

driving test equipment can both collect network data and they slightly differ

from each other.

1) Scanner

The scanner is used to collect complete radio network information and provide

functions such as pilot analysis test and frequency spectrum analysis test.

2) Test UE

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The test UE is used to learn the use condition of actual network subscribers and

collect the downlink information of the network. It completes the following

functions:

UE measurement data collection: Pilot Power, Ec/Io, UE Tx Power, Neighbour

cells, RSS, FER/BLER, etc.

Call type event and performance statistics: Call drop ratio, blocking ratio, call

success ratio, handover success ratio, voice QoS, data service rate statistics, etc.

Collection of air interface signaling: L3 message decoding for access, paging,

synchronization and uplink/downlink service

4. The following principles shall be observed during the driving test:

1) The WCDMA system is a self-interference system and the DT result varies with

the specific network load condition. Therefore, please confirm the network load

before the driving test.

2) Test time

Choose the appropriate test time according to the load condition of the network.

The busy-hour test generally applies to networks that have been formally put

into operation for a period of time. The busy-hour driving test is usually

conducted at the most busy time of the network, that is, from Monday to Friday

during non-holiday periods and the busy hour from 9:00 to 10:00 everyday.

For networks without large-scale subscriber number allocation, the loaded

driving test can be conducted at a normal time, such as the time period from

9:00 to 21:00 everyday.

For networks that have completed large-scale subscriber number allocation, the

loaded driving test can only be conducted at the midnight when there is very

little traffic, such as the time period from 0:00 to 5:00 everyday, so as to

accurately simulate the loads and reduce the impact of the test on subscribers in

the actual network.

For networks without large-scale subscriber number allocation, the unloaded

driving test can be conducted at a normal time, such as the time period from

9:00 to 21:00 everyday.


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For networks that have completed large-scale subscriber number allocation, the

unloaded driving test can only be conducted at the midnight when there is very

little traffic, such as the time period from 0:00 to 5:00 everyday, so as to

accurately reflect the radio performance of the network, facilitate the

comparison with the loaded test to discover if the problems in the network are

caused by the load, and reduce the impact of the test on subscribers in the actual

network.

Without taking the traffic situation into consideration, generally the test of a

very big city shall last for eight hours, that of a big city shall last for six hours

and that of a medium-sized city shall last for four hours.

Note:

Try to cover the service areas specified in the network plan while ensuring the test

duration.

3) Test routes

Before the driving test, the test routes must be planned first and the test range is

the areas that should be covered by the network in this phase of project. The test

routes must cover: a important urban places such as the densely-populated

areas of the city center, major backbone roads of the city, living area, banks of

the river and roadways; b important roads, areas with a large passenger flow

and important areas such as tourist spots; and c express highways, national

highways, provincial highways and other important roads (including roads in the

important countryside). If conditions permit, it may also include railways and

waterways. It shall cover the whole service area as much as possible.

By the area of the test routes, the driving test may fall into the urban driving test

and the main road driving test.

The urban driving test routes shall cover: a) important urban places such as the

densely-populated areas of the city center, major backbone roads of the city,

living area, banks of the river and roadways; and b) areas with a large passenger

flow and important areas such as tourist spots.

The main road driving test routes shall cover express highways, national

highways, provincial highways and other important roads (including roads in the

important countryside). It may also cover railways and waterways upon the

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Customer’s request.

The driving test routes of the CS domain service may be the same as those of the

PS domain service, or the test routes of the PS domain service may be adjusted

upon the Customer’s request.

Note:

Not all optimization belongs to network-wide optimization. The network-wide test may

be spared for local optimization.

4) Please follow the requirements below during selection of the test routes:

The driving test routes should be radial and circular routes.

A radial route can reflect the relationship of signal quality to change with

changes of the Node B distance.

A circular route can be used to predict signal quality of the Node B in different

directions.

During the optimization test, generally three test routes should be defined for

each Node B cluster. Please keep consistency of the test routes before and after

the optimization.

Fig. 8.5-1 Selection of the Test Routes

5) The consistency of the driving test condition shall be ensured before and after

the optimization.

The process of network optimization can be simply summarized as follows:

Network performance test -> Network optimization and adjustment -> Conduct


231231231231

the network performance test again to assess the effect of optimization.

Obviously, it is very important to keep consistency of the test condition before

and after the optimization.

The following factors may cause inconsistency of the test condition before and

after the optimization:

Different test tools (including parameter settings) are used before and after the

optimization

Different antennas or antenna feeders (not calibrated) are used before and after

the optimization

Different analysis staffs process the data before and after the optimization

Different test routes are selected before and after the optimization

The moving speed of the UE along the test routes varies before and after the

optimization

The network load level differs before and after the optimization, which will have

influence on the Ec/Io

Inconsistent test time periods

The following measures can be taken pertinently to ensure consistency of the test

condition before and after the optimization:

Try to use the same test tool and adopt the same parameter setting before and

after the optimization

Use the same test antennas and antenna feeders before and after the optimization

Ensure that the same analysis staff processes the data before and after the

optimization

Use the same test routes before and after the optimization

Select the sampling by distance rather than sampling by time for the data

sampling mode so as to ensure consistency of the UE’s moving speed. If the

driving test tools cannot be implemented with the sampling mode by distance,

try pausing data collection when the red lamp is lit

Check if the tested area is ongoing with the load test and ensure that the test is

conducted in the same time period on the day, so as to obtain basically the same

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network load condition

Conduct the test in the same time period

4. CS domain service

For the driving test of the CS domain service, one network load condition out of

the busy-hour test, the loaded test and the unloaded test may be selected upon

the Customer’s request, and the continuous long call test or the periodic call test

may be appropriately chosen according to the Customer’s request.

For the urban driving test, generally periodic calls are recommended (to test

such indexes as the cal completion ratio and the call drop ratio), considering that

the vehicle moving speed is slow, there are quite many Node Bs and the network

performance largely varies with the specific area. The call setup time, call hold

time and call gapping (idle time) are 10 seconds, 60 seconds and 5 seconds by

default, but they can be adjusted upon the Customer’s request.

For the main road driving test, generally continuous long calls are recommended

(to better reflect the handover performance of the network) so as to ensure the

continuity and integrity of data since the vehicle moves rather fast. If necessary,

periodic calls may also be adopted for the main road driving test.

5. PS domain service

The PS domain service test is generally done at an idle time, that is, the driving

test of the PS domain service is done when the network has no load or only has a

light load. The purpose of completing the test at an idle time is to avoid the

incomparability of test data of different areas caused by uneven distribution of

subscribers or avoid the influence of the driving test of the PS domain service on

normal use of voice subscribers in the network. The network load for the driving

test of the PS domain service may also be chosen upon the Customer’s request.

The driving test of the PS domain service shall be performed in the areas with

important requirements for data services. The test routes in these areas shall be

as minute as possible. For the other areas with possible requirements for data

services, the important roads shall be tested.

The driving test items of the PS domain service shall include the following:

Attachment success ratio, PDP Context activation success ratio, average


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activation time of the PDP Context, communication interruption ratio, average

downlink transmission rate and average uplink transmission rate.

The pilot signals on the test routes shall be so good as to originate calls for the

PS domain service. In addition, the test items can be counted simultaneously in

one operation, for example, we can count the number of PDP Context activation

successes in an operation and then count the number of communication

interruptions and the time needed for each PDP Context activation.

6. Characteristics of driving test data

They include geographical location information

The test result is restricted to a certain extent due to restrictions of the selected

test routes

8.5.4.2 Call Quality Test (CQT) Data

1. Dial calls at the fixed location, record the data at the test location and dial

multiple calls at each test point. The fixed-point CQT test includes the CS

domain service CQT and the PS domain service CQT. The specific test content

is related to the Customer’s requirements and depends on the actual situation.

2. The following principles shall be observed during the CQT:

1) Test time

In principle, the CQT test shall be conducted from 9:00 to 10:00 everyday from

Monday to Friday during non-holiday periods.

2) Test point selection

The following factors shall be comprehensively taken into account during the

selection of a test point:

The traffic of the area where the test point is located. Generally, a place with

large traffic is selected for networks that have been formally put into operation.

The geographical factors of the area where the test point is located. 80% of the

test points shall be indoor while 20% outdoor. In addition, the test points shall be

evenly distributed in terms of geographical distribution.

Note:

85% of the test points shall be indoor: The selected test points must be the

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indoor test points with a coverage plan prepared and actual conversation

requirements.

Radio environment of the area where the test point is located. The places

installed with a repeater or an indoor distribution system shall be preferred as

the test points.

Areas where network problems possibly exist. The places that may possibly be

blind spots, such as the streets between high-rise buildings or places located in a

multi-carrier area, shall be selected as the test points.

3) Precautions on selection of test points

80% of the test points shall be indoor while 20% of the test points shall be

outdoor.

The indoor test points shall cover important places of the city, such as star hotels,

terminals of airports, waiting rooms of railway stations, long-distance bus

stations, metro stations, port docks, top-grade residential communities,

governmental departments, operators’ office buildings and business halls, large

shopping marts/restaurants/entertainment places, top-grade office buildings,

exhibition centers and important urban tourist spots. For places such as airports,

railway stations, star hotels, large shopping marts, top-grade office buildings and

port docks, their public places are generally selected as test points: Airport

terminals, waiting rooms of railway stations, halls of hotels, meeting centers,

restaurants, entertainment centers, underground parking lots, top-layer guest

rooms and port docks. When conducting the test inside a high-rise building,

make five MO (Mobile-Originated) calls on the first floor (including two MO

calls in the underground parking lot), five MO calls on the top floor and 10 MT

(Mobile-Terminated) calls on the intermediate floors. The other test points shall

be evenly distributed after the geographical and traffic factors are

comprehensively taken into account, and the test shall focus on the important

areas.

Residential areas at the coverage border and streets between high-rise buildings

shall also be included in the outdoor test points. In addition, the tourist spots

shall be covered.


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Note:

A three-star hotel is an important place for a small- or medium-sized city;

therefore, all three-star hotels shall be selected as mandatory test points.

Generally, at least 60 test points shall be selected for a very big city, 40 for a big

city, 30 for a medium-sized city and 20 for a small city.

The specific test points shall be selected in accordance with the above principles

and the actual situation of the project. They shall be stated in the submitted

report. The selection of test points for the PS domain service may differ from

that of the CS domain service, or some test points with qualified signals may be

chosen for the PS domain service test, in addition to the test points selected for

the CS domain service test.

3. CS domain service

The CQT test items of the CS domain service include the coverage ratio, call

success ratio, call drop ratio, poor conversation quality ratio and average call

delay.

Record parameters of the UE such as downlink receiving power (RxPower),

RSCP and Ec/Io with the related test software. Record the number of MOC

successes, MTC successes, failures and call drop times. Get the number of calls

with poor conversation quality through subjective feeling and evaluation. And

record the delay of each call with the test software.

The data of all test points are used to count the coverage ratio. However, to

count the call success ratio, call drop ratio, poor conversation quality ratio and

average call delay, you must select the test points whose receiving power

(RxPower) is equal to or larger than –95 dBm and whose Ec/Io is equal to or

larger than –14 dB (the thresholds of Ec/Io and RSCP may differ with the

specific service, that is, the pilot signal should be so good as to originate calls

for the service to be tested), because these parameters are significant only when

the coverage is ensured.

4. PS domain service

The CQT test items of the PS domain service shall include the following:

Attachment success ratio, PDP Context activation success ratio, average

activation time of the PDP Context, communication interruption ratio, average

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downlink transmission rate and average uplink transmission rate.

The pilot signals on the test routes shall be so good as to originate calls for the

PS domain service. In addition, the test items can be counted simultaneously in

one operation, for example, we can count the number of PDP Context activation

successes in an operation and then count the number of communication

interruptions and the time needed for each PDP Context activation.

5. Characteristics of the CQT data

They include geographical location information

The test result is restricted to a certain extent due to restrictions of the selected

test points

8.5.4.3 OMC Performance Measurement Data

1. The OMC performance measurement data extraction method applies to

networks that have been put into large-scale commercial application. The

measurement data are objective and abundant, reflecting the running quality of

the whole network statistically. The network performance indices thus obtained

can serve as the most essential reference for assessing the network performance.

2. Extraction of OMC performance measurement data

The counter values needed for calculating the network KPI can be flexibly

extracted and counted according to different statistical range. Statistical

performance reports can be customized according to the Customer’s

requirements.

3. Characteristics of OMC performance measurement data

The background NMS indicates the running quality of the network it manages

from the plenty of sampling data statistics.

The statistical range flexibly varies. Some use the RNC as the statistical unit

while others logically use the Cell as the statistical unit.

A variety of network performance index counters are provided.

8.5.4.4 Subscriber Complaint Information

As the end users of network services, common subscribers are most directly sensitive


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to network performance. The problems complained by subscribers must be solved as

soon as possible. The subscriber complaint information has the following

characteristics:

It most directly reflects the shortcomings of the network

It contains specific geographical location information in most cases

The complained faults are generally about poor signal coverage, difficulty in

making calls and call drop

8.5.4.5 Alarm Information

Alarm information refers to the alarm information of the RNC, Node B, and CN

background NMS. It is a centralized embodiment of the abnormalities or near

abnormalities during the equipment use or network running.

Caution:

Give an eye to and check the alarm information during the network optimization period,

so as to timely discover pre-alert information or the problems that have occurred and

thus avoid the occurrence of accidents.

8.5.4.6 Other Data

In addition to the data listed previously, generally there are the data obtained through

the signaling analysis system, the network traffic test system, the voice quality

assessment system and other systems. These are specialized data used to help accurate

location of network problems.

8.5.5 Data Analysis

Data analysis means to understand the running quality of the network through analysis

of the driving test data, CQT data, OMC performance measurement data, subscriber

complaint information, alarm information and other data, so as to assess the

performance of the network.

Different data analysis methods shall be taken for different means to obtain the network

data, as described below.

8.5.5.1 Driving Test Data Analysis

Driving test data analysis means to make geographical analysis, table analysis,

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graphical analysis, custom event analysis and statistical analysis of the network data

collected by the signal receiver and the test UE.

Through it, the following major network indices can be obtained:

Coverage ratio, call success ratio, call drop ratio, conversation quality and

handover success ratio for the CS domain service

PDP Context activation success ratio and average uplink/downlink transmission

rate for the PS domain service

We can combine these indices and test conditions for analysis to basically learn the

coverage loopholes, interference, pilot pollution and other information of the network.

Geographical analysis

Through geographical analysis, we can vividly view the signal intensity and

quality, Node B distribution, cell coverage, interference, pilot pollution and

other information of the current network. Generally, the pilot signal intensity Ec

distribution map, pilot signal quality Ec/Io distribution map, pilot pollution map

and other maps of the signal Node B, the Node B cluster and the whole network

should be formulated. In addition, a comparison of the effect before and after the

optimization must be made.


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Fig. 8.5-2 Geographical Analysis Window

Table analysis

The table shows the values of all parameters in a data table. They can be

browsed, searched and analyzed.

Fig. 8.5-3 Table Analysis Window

Graphical analysis

Graphical analysis means to describe the two-dimensional features of a

parameter in a curve diagram. At present, there are two types of analysis:

Common curve diagram analysis and PDF curve diagram analysis.

1) Common curve diagram analysis describes the features of a parameter in a

two-dimensional curve diagram.

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Fig. 8.5-4 Common Curve Diagram Analysis Window

2) PDF curve diagram analysis is probability distribution curve analysis

Fig. 8.5-5 PDF Curve Diagram Analysis Window


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For an area with high call drop ratio (or poor service quality), the data playback, query

and statistics functions provided by the specialized optimization analysis software

ZXPOS CNA1 (UMTS Edition) may be used to make a further analysis.

Custom event analysis

Custom event analysis mans to judge the status of an event via the interface

provided by the analysis software CNA1 to users by setting the logic conditions

between messages. It can be used to query the events you are interested in.

Fig. 8.5-6 Custom Event Analysis Window

Statistical analysis

Statistical analysis includes statistical analysis of the original test data in the

specified time period and that of the original test data in the specified area. It can

be used to count the number of test points and scale of a parameter item and

display the result in the form of a diagram (bar chart or pie chart) or table. The

following figure shows the statistical setting of RxPower:

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Fig. 8.5-7 Original Data Statistics Setting Page

Rx Power

0 0. 798. 61

28. 98

47. 55

14. 07

0 0. 79

9. 4

38. 38

85. 93

100

0

10

20

30

40

50

60

70

80

90

100

( - I NF,- 100]

( - 100,- 90]

( - 90,- 80]

( - 80,- 70]

( - 70,- 60]

( - 60,+I NF)

Range

Perc

enti

le(%

)

0

10

20

30

40

50

60

70

80

90

100

Per cent i l e( %)Cumul at i ve Per cent i l e( %)

Fig. 8.5-8 Bar Chart Formed According to the Statistical Result

8.5.5.2 CQT Data Analysis

Analyze the CQT test data with the specialized network optimization analysis software

ZXPOS CNA1 (UMTS Edition).

Let us take delay analysis for example. The Delay Analysis page in the message


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analysis window is illustrated in the following figure.

Fig. 8.5-9 Message Analysis Window – Delay Analysis

The analysis items related to the CQT data also include call event analysis, custom

event analysis, geographical event analysis, geographical delay analysis and statistical

item analysis.

The CQT test data analysis result includes call success ratio, call drop ratio, call delay,

conversation quality and average data service rate. From these data, we can learn the

indoor coverage and interference condition of the network in the selected area.

1) Call success ratio

Call success ratio = [Number of successful calls/total number of calls] × 100%

2) Call drop ratio

Call drop ratio = [Number of dropped calls/total number of successful calls] ×

100%

Note:

If continuous long calls are adopted, the total number of successful calls is equal to the

total call duration (in seconds) divided by 90 seconds.

3) Average call delay

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It refers to the average delay measured with the WCDMA network optimization

analysis software ZXPOS CNA1. It is the interval from the time when the

calling UE receives the Alerting signaling directly sent from the CN to the time

when the calling UE sends the first RRC Connection Request.

Note:

The random access delay may vary greatly due to the different radio environment

quality caused by different network loads. Therefore, the average call delay is

measured on the basis of the network load.

4) Average data service rate

Count the PDP Context activation success ratio and the average uplink/downlink

transmission rate of all test points with the WCDMA network optimization

analysis software ZXPOS CNA1, so as to get the PDP Context activation

success ratio and the average uplink/downlink transmission rate of the network.

8.5.5.3 OMC Performance Measurement Data Analysis

OMC performance measurement data analysis can be used to obtain the general

performance indexes (GPIs) and the key performance indexes (KPIs) of the radio

network, which are an important reference for assessing the network performance.

Through analysis of the OMC performance measurement data, we can directly locate

the range of area where a problem occurred and thus help accurate location of the

problem.

The resource utilization is indicated by these indexes: Worst cell ratio, super busy cell

ratio, super idle cell ratio and cell code resource availability.

The indexes obtained from the OMC also include those that can reflect the running

quality of the network: Access success ratio, call completion ratio, call drop ratio and

call delay.

These indexes reflect the handover performance of the system (handover success ratio):

Softer handover success ratio, soft handover success ratio, Inter-Iur soft handover

success ratio, hard handover success ratio and inter-system handover success ratio.

Note:

Handover is an important part of system mobility management and handover success


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ratios are also important indexes of the system mobility management function.

WCDMA handover falls into softer handover, soft handover and hard handover. Softer

handover occurs to different cells in the same Node B; soft handover falls into soft

handover between Node Bs in the same RNC and that between different RNCs (with

the Iur interface involved). Softer handover and soft handover both belong to

intra-frequency handover. Hard handover falls into co-frequency hard handover,

inter-frequency hard handover and inter-system handover. The co-frequency hard

handover occurs between different RNCs (without involving the Iur interface).

Listed below are several KPIs:

1） Worst cell ratio

Description:

A worst cell refers to a cell whose call drop ratio is more than a% or service congestion

ratio is more than b% in a certain traffic condition. The worst cell ratio refers to the

percentage of worst cells to the total number of available cells of the system.

Calculation formula:

Worst cell ratio = Total number of worst cells / total number of available cells * 100%

The total number of worst cells refers to the number of cells whose call drop ratio is

more than a% or service congestion ratio is more than b%, where a% and b% are

determined by the configuration. The total number of available cells refers to the

number of available cells in the current system.

2） Super busy cell ratio

Description:

A super busy cell refers to a cell whose carrier transmit power utilization ratio is more

than c%. The super busy cell ratio refers to the percentage of super busy cells to the

total number of cells.


Super busy cell ratio = Total number of super busy cells / total number of available

cells * 100%

The total number of super busy cells refers to the number of cells whose carrier

transmit power utilization ratio is more than c%. Here, c% is determined by the

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configuration. The total number of available cells refers to the number of available

cells in the current system. The RNC can count the average value of carrier transmit

power of a single cell of the Node B by receiving measurement reports from the Node

B. The utilization ratio of carrier transmit power can be obtained after the maximum

value of carrier transmit power is divided by the average value of carrier transmit

power.

3） Cell code resource availability

Description:

The downlink scramble set (main scrambles) of the WCDMA system is restricted to

512 scrambles and each cell is allocated a main scramble. A main scramble of a cell

corresponds to a spreading code tree (binary tree) and each level of the code tree

defines a channel code whose length is the spreading factor (SF). The SF value ranges

from 4 to 256. A main scramble is used to identify a cell and a downlink channel code

is used to identify a subscriber in the cell. The feature of this spreading code tree is that

the occupation of a node will cause blocking of all the sub-code tree nodes and the

higher-layer nodes directly connected to it.

The cell code resource availability indicates the ratio of unallocated code resources on

the current code tree to all the code resources on the current code tree. It can accurately

reflect the code resource status of the current cell.


Cell code resource availability = 1- (the number of codes allocated by the SF to 4-code

nodes/4 + the number of codes allocated by the SF to 8-code nodes/8 + the number of

codes allocated by the SF to 16-code nodes/16 + the number of codes allocated by the

SF to 32-code nodes/32 + the number of codes allocated by the SF to 64-code nodes/64

+ the number of codes allocated by the SF to 128-code nodes/128, the number of codes

allocated by the SF to 256-code nodes/256 + the number of codes allocated by the SF

to 512-code nodes/512) * 100%

The characteristics of the spreading code tree shall be taken into account when

counting the current number of available cell codes. When a certain node is occupied,

all its sub-nodes will not be available any longer and therefore they shall not be

counted into the available codes.


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4） Soft handover success ratio

Description:

Soft handover takes place between different Node Bs and the diversity signals are

selectively merged in the RNC. The soft handover success ratio reflects the mobility

performance of the system and can be sensed indirectly by subscribers. Here, the

inter-Iur soft handover is not considered. Instead, the inter-Iur soft handover success

ratio is independently assessed as an index.

Calculation formula (two are available):

Soft handover success ratio 1 = (the number of times to successfully add a radio link

during soft handover + the number of times to successfully delete a radio link during

soft handover) / (the number of attempts to add a radio link during soft handover + the

number of attempts to delete a radio link during soft handover) * 100%

Soft handover success ratio 2 = (ActiveUpdateComplete times / ActiveUpdate times *

100%

5） Softer handover success ratio

Description:

Softer handover takes place between cells of the same Node B and the diversity signals

are merged at the maximum gain ratio in the Node B. It reflects the mobility

performance of the system and can be indirectly sensed by subscribers.


Softer handover success ratio = Softer handover success times / softer handover

attempts * 100%

6） Access success ratio

Description:

The access success ratio (RRC connection setup success ratio) reflects the capability of

a radio network to admit UEs, and RRC connection setup success means that the UE

has established a signaling connection with the network. This index is also an

important index to measure the call completion ratio and is included in the call

completion ratio. It affects the call success ratio and is a performance index that can be

directly sensed by subscribers.

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Many reasons may cause an RRC connection setup request, including UE-initiated

RRC connection setup requests due to cell selection, cell reselection, call and location

updating. In general, only the access success ratio due to call reasons will be counted.

Because non-call access and call access have slight difference, the access success ratio

here does not differentiate the causes of the RRC connection setup request.

The access success ratio is expressed by the ratio of RRC connection setup success

times to the total RRC connection setup attempts, whose signaling messages are the

UE-initiated RRC CONNECTION REQ times and the RRC CONNECTION SETUP

COMPLETE times in turn.


Access success ratio = RRC connection setup success times / RRC connection setup

attempts * 100%

Here, the influence from retransmission shall also be considered.

7） RAB establishment success ratio

Description:

RRC connection setup success means that the UE has established a signaling

connection with the network and is the first step of establishing a call connection,

whereas RAB establishment success means that a user plane connection has been

successfully allocated to the subscriber (RAB refers to the bearing of the user plan and

is used to transmit voice, data and multimedia services between the UE and the CN),

and is the last step of establishing a call connection.

The RAB establishment success ratio is a performance index that can be directly

sensed by subscribers. It falls into the RAB establishment success ratio of the CS

domain and that of the PS domain, and can be further divided according to the specific

services.

The RAB establishment success ratio is expressed by the ratio of RAB assignment

success times to RAB assignment attempts, whose signaling messages are RAB

ASSIGNMENT REQUEST (RAB establishment) and RAB ASSIGNMENT

RESPONSE (RAB establishment success) in turn.



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RAB establishment success ratio of the CS domain = RAB assignment success times of

the CS domain / RAB assignment attempts of the CS domain * 100%

RAB establishment success ratio of the PS domain = RAB assignment success times of

the PS domain / RAB assignment attempts of the PS domain * 100%

RAB establishment success ratio = (RAB assignment success times of the CS domain

+ RAB assignment success times of the PS domain) / (RAB assignment attempts of the

CS domain + RAB assignment attempts of the PS domain) * 100%

8） Call drop ratio

Description:

The call drop ratio reflects the communication hold capability, stability and reliability

of the system. It is an important performance index of the radio communication system.

It directly relates to psychological feeling and use confidence of subscribers.

The radio system call drop ratio only takes into account the dropped calls caused by

abnormalities of the access side rather than those caused by abnormalities of the CN

side or the forced call drop processing taken by the load control process in radio

resource management in the case of overload.

In addition, we suppose that the CN will send a RAB assignment release command. In

practice, the CN may directly send the Iu interface signaling connection release

command without sending the RAB assignment release command.

When call drop occurs, the system may trigger one of the two signaling procedures:

One is the RAB release request and the other is the Iu interface signaling connection

release request. The radio system call drop ratio falls into the call drop ratio of the CS

domain and that of the PS domain. In the DT and CQT test content as we previously

described, the call drop ratio of the PS domain is also called the communication

interruption ratio, so as to differentiate itself from the call drop ratio of the CS domain.


Call drop ratio of the CS domain = (RAB release requests of the CS domain + Iu

interface signaling connection release requests of the CS domain) / RAB assignment

success times of the CS domain * 100%

Call drop ratio of the PS domain = (RAB release requests of the PS domain + Iu

interface signaling connection release requests of the PS domain) / RAB assignment

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success times of the PS domain * 100%

Radio subsystem call drop ratio = (RAB release requests of the CS domain + Iu

interface signaling connection release requests of the CS domain + RAB release

requests of the PS domain + Iu interface signaling connection release requests of the

PS domain) / (RAB assignment success times of the CS domain + RAB assignment

success times of the PS domain) * 100%

9） Call delay

Description:

The call delay reflects the system’s speed to respond to service calls and it directly

relates to the psychological feeling and use confidence of subscribers. It can fall into

the average call delay of the CS domain and the average PDP Context activation time

of the PS domain, and may be further divided according to the specific services. To

count the call delay, authentication and TMSI reallocation functions must be enabled

first and whether to calculate the ciphering time shall depend on the specific service

needs.

The average call delay of the CS domain falls into the call delay from UE to UE and

that from UE to PSTN.


Average call delay of the CS domain = ∑ the time when the calling UE receives the

Alerting signaling message directly sent from the CN – the time for the calling UE to

start sending the first RRC Connect Request / ∑ the number of UE calls

Average PDP Context activation time of the PS domain = ∑ the time when the UE

receives the DT (Active PDP Context Accept) signaling message – the time when the

UE sends the DT (Active PDP Context Request) signaling message / ∑ the number of

UE calls

8.5.5.4 Subscriber Complaint Information Analysis

Because of diversity of subscribers’ descriptions of problems and difference of their

expressions in the subscriber complaint information, the problem may often relate to

the transmission system, the charging system and other relevant systems, in addition to

the Node B. Therefore, we should carefully identify and find the information that can


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really reflect the network status.

The subscriber complaints may directly indicate the symptoms and geographical

location of a problem. The following information can be obtained through

reorganization of them:

Places with poor network coverage

Places with low call success ratios

Places with high call drop ratios

Places with poor voice signal quality

8.5.5.5 Alarm Information Analysis

Alarm information contains plenty of abnormal pre-alert information during the

network running and can help us quickly locate problems and find out the way to solve

them. When the network performance deteriorates due to occurrence of a certain fault,

the OMC performance measurement indexes will often be abnormal. Therefore, it will

be of great help to network fault location and removal if we can find out the correlation

between OMC performance measurement indexes and the relevant alarm information.

If we determine from the alarm information that the Node B is problematic (such as

VSWR alarm), then we need to check the problematic Node B and troubleshoot its

equipment faults.

8.5.5.6 Analysis of Other Data

Some network problems are caused by poor radio network coverage or poor signal

quality (for example, there are many causes for soft handover failure). In that case, the

above-mentioned analysis methods would be unable to locate the faults and it is then

necessary to analyze the specific data.

For example, we can trace the signaling of various interfaces such as Uu, Iub and Iur,

count the signaling traffic and messages at each interface and find out the exceptional

signaling procedures; and combine the other statistical data to more accurately locate

the faults and discover the exceptions that can be hardly discovered at usual times, so

as to eliminate hidden troubles.

Below is an example of decoding analysis of the air interface signaling by use of the

ZXPOS CNA1:

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The list of messages collected by the test software ZXPOS CNT1 is illustrated in the

following figure:

Fig. 8.5-10 Air Interface Message List Window

The lower half of the window as shown in the above figure is the message decoding

subwindow. It shows the decoding results of the selected system message and parses

the content of each system information block according to the system information

block stream in the system message. For the system information blocks transmitted

segment by segment, it will assemble the segmented system information block streams

into a complete information block stream during the parse, decode the complete

information block stream and then display it.

During message analysis, the message filter condition can be set so that you can

conveniently get the needed information, as shown in the figure below:


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Fig. 8.5-11 Message Analysis Window - Setup Log Mask (Message Filter Setting)

1） Common Analysis Methods

Discussed above are the analysis methods for different data acquisition means. In

addition to these analysis methods, some other analysis methods are available during

the optimization:

Multi-dimensional analysis, tendency analysis, accident analysis, comparative analysis,

rank analysis and cause & impact analysis.

Multi-dimensional analysis

A dimension refers to the focus and direction of solving a problem.

Multi-dimensional analysis is to analyze data from multiple different angles and

their combinations.

For example, we shall focus on access, handover and other relevant issues in

addition to call drop when dealing with a call drop problem.

Tendency analysis

Tendency analysis is to analyze the tendency of changes with the time in the

time sequence to find its law, as shown in the following figure:

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Fig. 8.5-12 Tendency Curve of Changes of the Call Drop Ratio with Time

Accident analysis

Accident analysis is to find out the exceptional data such as excessive high

index, excessively low index and excessive large change amplitude among the

bulky data, and further mine data on the impact causes, as shown in the

following figure:

The call drop ratio is abnormally high and it is necessary to find if any problem occurs to this time period

Fig. 8.5-13 High Call Drop Ratio and Time Period Statistics

Comparative analysis


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Comparative analysis means to compare different data sets from the same angle,

so as to find the differences and further explore the causes of differences. This

method is often applied in signaling procedure analysis.

Rank analysis

Rank analysis means to find out the Top N or Bottom N data by a certain

classification method from the bulky data. These data shall deserve special

attention. An example of rank analysis is the common worst cell method.

Cause and impact analysis

Cause and impact analysis means to mine the impact factors from the bulky data

for a certain result generated and analyze the importance of different factors or

their combinations.

Note:

Every analysis method is effective for certain problems and has certain restrictions. To

locate a specific equipment problem, parameter configuration problem (including

engineering parameters and radio parameters) or radio resource utilization problem, a

single analysis method can hardly work and you must appropriately combine the

above-mentioned methods.

Through data analysis, we should learn the basic conditions of the network such as

coverage and interference, the operation performance & quality such as access success

ratio, call drop ratio and handover success ratio of the network, and the network

resource utilization such as worst cell ratio and cell code resource availability.

Network Assessment

First summarize the network tests and analysis done previously and output the

Assessment Report on the WCDMA Radio Network in XX Service Area.

Note:

The network assessment report is mandatory at the initial stage of the optimization but

is not required after the optimization, because the network optimization report to be

output after the network optimization and adjustment already contains an assessment of

the network performance after the optimization.

The comprehensive score of network assessment can be obtained after the DT score,

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the CQT score and the OMC index score are weighted and summated.

Comprehensive score of the network = DT score * 40% + CQT score * 30% + OMC

index score * 30%

Note:

If the relevant performance data cannot be obtained from the OMC, for example, for

the network assessment before subscriber number allocation, the comprehensive score

of the network may simply be obtained through calculation of the DT score and the

CQT score:

Comprehensive score of the network = DT score * 60% + CQT score * 40%

The network assessment is used to discover the problems existing in the network, guide

the next step of network optimization and facilitate a comparison of the network

performance before and after the network optimization.

8.5.6 Parameter Check (Optional)

Disqualified indexes of the network can be discovered during data analysis. If it is

found that some parameters are improperly configured and affect the network

performance, you must check the parameter configuration data of the problematic

Node B. The check shall cover these contents:

1. Check the single site

Check if the site is in the correct position, if the antennas used are of the correct

model, if the mounting height, azimuth and down tilt of the antennas are

consistent with the plan, and if the antenna feeders used are of the correct model

and have appropriate lengths; test the VSWR of the antenna feeders, and check

the other aspects.

2. Check if the cell radio configuration parameters are consistent with the planned

values

A cell is generally represented by the following parameters: Frequency,

scramble and common physical channel configurations.

The common physical channels include the Primary Common Pilot Channel

(PCPICH), the primary synchronization channel (PSCH), the secondary


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synchronization channel (SSCH), Primary Common Control Physical Channel

(PCCPCH), the Packet Random Access Channel (PRACH), the Secondary

Common Control Physical Channel (SCCPCH), the access indication channel

(AICH) and the paging indication channel (PICH). Please check if the transmit

power of these channels is set to the planned values.

3. Check the relevant service configuration parameters of voice services and data

services.

8.5.7 Problem Localization

8.5.7.1 Types of Network Problems

Radio network problems occur in the following aspects: Equipment software and

hardware, engineering parameters, radio parameters, network capacity and others.

1. Equipment software and hardware problems

Equipment problems include software version problems, Node B board

problems, antenna feeder quality problems and others.

The network problems that may be caused by equipment problems include the

following: No signal coverage in the planned area, failure of service initiation

though there is signal, failure of inter-Iur handover (due to RNC software

version problems), and others.

2. Engineering parameter problems

These problems refer to improper engineering parameter settings, such as the

position, mounting height, down tilt and azimuth of the antennas. The main

network problems thus caused include poor network coverage, severe

interference, severe pilot pollution, call drop and low handover success ratio.

3. Radio parameter problems

There are many network radio parameters: Paging and registration, access, load

and admission control, handover, power control, cell reselection parameters and

the adjacent cell list. Improper radio parameter configuration may cause the

following network problems: Network access failure of the UE, low call

completion ratio, call drop, handover problems and others.

4. Network capacity

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The network load increases as the number of subscribers increases. Due to the

self-interference feature of the WCDMA system, the network performance and

the QoS will decrease. In this case, it is necessary to expand the network

capacity.

Note:

The localization of network problems is a complex process that requires you to

combine the test and statistical data by using different analysis means.

8.5.7.2 Problems and Related Influence

1. Equipment software and hardware

For hardware faults, usually there is alarm information at the background, such

as the antenna feeder VSWR alarm and the low power alarm. Some hardware

faults without any alarm can also be located through network data analysis. The

occurrence of an equipment fault will cause poor performance indices of a single

Node B or a Node B cluster.

2. Network engineering parameters

These parameters include the azimuth, down tilt, mounting height and position

of the antennas. To handle the coverage and interference problems during the

network optimization after the network construction is completed but before the

number allocation, you can adjust the network engineering parameters.

1) Coverage

Generally, the pilot signal strength is used to indicate the network coverage

conditions: The pilot strength received by 95% of the coverage areas shall be

greater than –89dBm (densely-populated urban areas) or –94dBm (urban areas).

The pilot signal quality is used to indicate the interference conditions: The pilot

Ec/Io measured in 95% of the coverage areas shall be greater than –10dB.

To locate a coverage problem:

Determine the coverage blind spots by analyzing the driving test data.

Evaluate the severity of these coverage blind spots and sort these spots in the

priority sequence.


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2) Interference

To locate an interference problem:

Determine the areas where the pilot Ec/Io is lower than the threshold. Check the pilot level of these areas (these areas may probably have more than

three pilot signals).

Find any unexpected pilot (such pilot signals come from the cells that are not

designed to provide coverage for these areas) from the pilots received by these

areas.

Network coverage and interference problems will cause KPIs such as call

success ratio, call drop ratio, access delay and handover success ratio to fail to

meet the requirements.

3. Radio parameters of the network

Radio parameters of the network are involved in both engineering optimization

and O&M optimization. One of the main tasks of O&M optimization is to

improve the network KPIs. This includes adjusting the access parameters,

paging parameters, power control parameters, handover parameters, search

parameters and other parameters.

1) Adjacent cell list

Due to the self interference feature of the WCDMA system, any strong signal

not in the adjacent set will cause strong interference to the current serving cell,

resulting in such problems as low call completion ratio, poor voice quality, high

call drop ratio, or failure to initiate high-speed services (the most frequent

problem is call loss caused by missing adjacent cell configuration). Do not

forget to put the adjacent cells with the best signal into the adjacent cell list.

Precautions related to adjacent cell list optimization:

The network planning tools can automatically plan the adjacent cell list by use

of a proper algorithm. Generally, the algorithm is based on the interference

among cells.

If the pilot signal of a certain cell is quite strong but the cell is not added to the

active set, then the signal of the cell becomes a very strong interference source.

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The adjacent cells can be configured unidirectionally or bidirectionally.

The following should be considered first during the setting of the adjacent cell

list: The interference generated by the cell and the possibility of becoming the

main serving cell of the UE.

2) Call parameters

Counter T300 indicates the call wait time and counter N300 indicates the

retransmission count. They are closely related to the call success ratio.

3) Handover parameters

The handover in the WCDMA system is divided into the following three types

according to the types of source cell and destination cell: Intra-frequency

handover, inter-frequency handover and inter-system handover. The following

text discusses several parameters affecting intra-frequency handover.

1A event: The signal of a primary CPICH enters the reporting range. Reporting

Range Constant and Hysteresis are important parameters used to judge whether

to trigger the 1A event. They affect the judgment threshold and hysteresis range

of the 1A event.

1B event: The signal of a primary CPICH goes out of the reporting range.

Reporting Range Constant and Hysteresis are important parameters used to

judge whether to trigger the 1B event. They affect the judgment threshold and

hysteresis range of the 1B event.

The 1C event takes place when the signal quality of a cell (cell1) in the

monitoring set is better than that of the worst cell (cell2) in the active set.

Hysteresis is the preference margin of the cell in the active set when the 1C

event is triggered.

The 1D event means changes have occurred to the best cell. Hysteresis is the

preference margin of the cell in the active set when the 1D event is triggered.

4) Inter-system handover

Subscriber access problems:

In the hybrid network of 2G and 3G, the dual-mode UE selects the 2G network

once being powered on and hence cannot access the 3G network. For some UEs,


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you may solve the problem by locking the frequency and the network. However,

calls may get lost when the UE reaches the coverage edge of the 3G network.

5) Inner loop power control

For the uplink, first the Node B measures the SIR of each radio link received,

and then compares it with the target SIR (SIRtarget) needed for the service. If

SIR is equal to or larger than SIRtarget, then the Node B sends a Transmitted

Power Control (TPC) command with a bit value being “0” to the UE through the

downlink control channel to request the UE to reduce its transmit power. If SIR

is less than SIRtarget, then the Node B sends a TPC command with a bit value

being “1” to the UE through the downlink control channel to request the UE to

increase its transmit power. Then the UE judges whether to increase or decrease

its transmit power according to the received TPC command and the power

control algorithm specified by the network layer. The adjustment step is

TPC_STEP_SIZE. This operating mechanism also applies to the downlink.

The inner loop power control algorithm and the power control step are important

factors affecting the power control effect.

4. Adjustment after capacity analysis or traffic grooming analysis

The “fine areas” in a city only account for a very small proportion of the

coverage area but can account for 80% of the total planned capacity. They are

the construction focus of the Customer’s WCDMA radio network and the major

source of the Customer’s future revenues. If the network capacity cannot be well

expanded to satisfy the huge upgrade requirements of these fine areas, the

Customer would suffer a big loss.

The following measures may be adopted: Adding Node Bs, using multiple

carriers, splitting cells, using microcell Node Bs and RF remote stations, and

others.

8.5.8 Formulation of the Optimization Plan

After the network problem is located, generally there is a set (or several sets) of

solutions available. You need to make the best optimization adjustment plan based on

the specific site conditions, and output the Optimization & Adjustment Plan for the

WCDMA Radio Network in XX Service Area. For different network problems,

different optimization & adjustment plans can be adopted:

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1. Adjustment strategy of equipment software and hardware problems

If software problems are found during parameter check, you need to timely

confirm the software version and update the software. Equipment hardware

problems often lie in board faults and you should replace the faulty boards then.

2. Adjustment strategy of engineering parameters

You may improve the network coverage and reduce the interference by adjusting

the azimuth, down tilt, mounting height and position of the antennas.

Caution:

Pay attention to the impact of the strategies on the coverage of the original serving area

of the cell.

However, to reduce the interference, it is far from enough to only adjust the

engineering parameters. You may also need to adjust other parameters (for example,

the transmit power of common channels of the cell).

3. Adjustment strategy of radio parameters

1) Adjacent cell list adjustment

Solve the possible problem of missing adjacent cell configuration by using the

professional optimization analysis software ZXPOS CNA1 (UMTS Edition) and

the adjacent cell planning tools and combining the driving test data.

2) Call parameter adjustment

To improve the call success ratio, you must optimize parameters such as T300

and N300. By reducing the value of T300 and increasing the value of N300, you

can shorten the wait time and increase the retransmission count, thus improving

the call success ratio.

Table 8.5-1 Adjustment of Call Parameters

ParameterSetting BeforeOptimization

Setting AfterOptimization

T300 D5000 D2000N300 3 5

3) Handover parameters


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If ping-pong handover occurs, you may increase the Hysteresis value of the 1A

event. If it is difficult to add the adjacent cell signal to the active set, you may

increase the value of Reporting Range Constant – Hysteresis/2. The higher value,

the lower judgment threshold of the 1A event.

4) Inter-system handover

To handle subscriber access problems:

Specify that 3G subscribers all should preferentially access the 3G network and

be retained in the 3G network.

When a 3G UE hands over to the 2G system and completes the call, it should

immediately complete registration in the 3G network first.

A EG subscriber should not conduct cell reselection from WCDMA to GSM

unless it has gone out of the 3G network coverage.

A 3G subscriber should immediately initiate the cell reselection procedure from

GSM to 3G once it returns to the 3G network coverage.

5) Inner loop power control.

The power control step may be adjusted to a slightly larger value if the signal

intensity changes rapidly due to the complex radio environment.

4. Network capacity expansion solution

The following capacity expansion solution is available for the fine areas:

Add carriers

Add power amplifiersTransmit diversity

Add RRUsMulti-layer coverage

Add carriersReplace the power

amplifiersThe capacityincreases by 48%

The capacityincreases by 34%

The capacityincreases by 50%

Cap

acity

Initial Stage Middle Stage Late Middle Stage Late Stage NetworkConstruction Phase

Fig. 8.5-14 V3 Series WCDMA Node B Equipment Expansion Roadmap

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As the WCDMA network subscribers keep increasing, we can add a carrier to

the network.

If the number of subscribers increases again after a carrier is added, we can add

a power amplifier for each carrier.

If the number of subscribers still increases, then we need to deploy the third

carrier and replace the power amplifiers with those of larger power.

In places where subscribers are especially densely populated, the multi-layer cell

expansion solution is recommended if three 20W carriers still fail to meet the

capacity requirements, that is, use RF remote station equipment to construct

micro cells where the macro cell coverage effect is not ideal or subscribers are

highly centralized.

8.5.9 Implementation of the Optimization Plan

Complete adjustments for the optimization in accordance with the Optimization &

Adjustment Plan for the WCDMA Radio Network in XX Service Area, and output the

Optimization & Adjustment Records on the WCDMA Radio Network in XX Service

Area.

8.5.10 Optimization Effect Verification

After implementing the network optimization solution, verify if the network problems

have all been solved or if the network performance has been improved.

1. During optimization effect verification, first collect the network running data

and then analyze the collected data.

2. After implementing the optimization solution, assess the network performance

once again by analyzing the DT data, CQT data, OMC performance

measurement data, subscriber complaints, alarm data and other relevant data.

3. Compare the performance indexes of the network after the optimization with

those before the optimization to verify if the network problems have all been

solved or the network performance satisfies the requirements after the

optimization.

Note:


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The network optimization workflow is also a process of testing -> analysis ->

assessment -> adjustment -> testing -> …

8.5.11 Project Acceptance

Conduct the acceptance test on the performance indices of the optimized network

against the contract clauses. The test routes, test points, call mode and other relevant

contents of the acceptance test shall be set according to the contract or the principles

determined in the requirement analysis phase. In principle, the Customer shall

participate in the acceptance test.

8.5.12 Document Archiving

After optimization effect verification and project acceptance, it is necessary to submit

the Optimization Report on the Radio Network in XX Service Area and archive the

related documents/data.

The network optimization report shall cover these contents: Analysis and localization

of the found problems, the optimization measures taken, a comparison of the indices

before and after the optimization, and suggestions on the outstanding problems of the

network or subsequent construction of the network.

zte wcdma npo primary02-200711 wcdma radio network planning and optimization

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