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Document number: UMT/IRC/APP/0033Document issue: 01.01 / ENDocument status: PreliminaryDate: 19/SEP/2001

Internal document - Not to be circulated outside Nortel Networks

Copyright2001 Nortel Networks, All Rights Reserved

Printed in France

NORTEL NETWORKS CONFIDENTIAL:

The information contained in this document is the property of Nortel Networks. Except as specif ically authorized in

writing by Nortel Networks, the holder of this document shall keep the information contained herein confidential

and shall protect same in whole or in part from disclosure and dissemination to third parties and use same for

evaluation, operation and maintenance purposes only.

The content of this document is provided for information purposes only and is subject to modification. It does not

constitute any representation or warranty from Nortel Networks as to the content or accuracy of the information

contained herein, including but not limited to the suitability and performances of the product or its intended

application.

The following are trademarks of Nortel Networks: *NORTEL NETWORKS, the NORTEL NETWORKS corporate

logo, the NORTEL Globemark, UNIFIED NETWORKS. The information in this document is subject to change

without notice. Nortel Networks assumes no responsibility for errors that might appear in this document.

All other brand and product names are trademarks or registered trademarks of their respective holders.


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20Nortel Networks confidential

UMT/IRC/APP/0033 01.01 / EN Preliminary 19/SEP/2001 Page 20/20

PUBLICATION HISTORY

19/SEP/2001

Issue 01.01 / EN, Update after internal review

By Arnaud PIAZZA


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CONTENTS

1. INTRODUCTION ...........................................................................................................................4

1.1. OBJECT ...................................................................................................................................4

1.2. SCOPE OF THIS DOCUMENT .......................................................................................................4

1.3. AUDIENCE FOR THIS DOCUMENT ................................................................................................4

2. RELATED DOCUMENTS..............................................................................................................4

2.1. APPLICABLE DOCUMENTS..........................................................................................................4

2.2. REFERENCE DOCUMENTS .........................................................................................................5

3. LINK BUDGET CALCULATION ...................................................................................................63.1. THEORETICAL EXPLANATIONS....................................................................................................6

3.1.1 Path Loss calculation......................................................................................................63.1.2 UL link budget calculation...............................................................................................83.1.3 Cell size calculation ........................................................................................................93.1.4 BS power calculation ......................................................................................................9

3.2. FIELD MEASUREMENT VALIDATION...........................................................................................10

4. LINK BUDGET VALIDATION .....................................................................................................11

4.1. PURPOSE...............................................................................................................................11

4.2. THEORETICAL EXPLANATIONS..................................................................................................12

4.3. SIMULATION ...........................................................................................................................13

4.4. FIELD VALIDATION TEST ..........................................................................................................13

5. PILOT AND NEIGHBOURING VALIDATION.............................................................................16

5.1. PURPOSE...............................................................................................................................16

5.2. VALIDATION TEST ...................................................................................................................16

5.2.1 Pilot coverage ...............................................................................................................175.2.2 Pilot pollution.................................................................................................................185.2.3 Neighbouring list ...........................................................................................................19

6. ABBREVIATIONS AND DEFINITIONS ......................................................................................20

6.1. ABBREVIATIONS......................................................................................................................20

6.2. DEFINITIONS ...........................................................................................................................20


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1. INTRODUCTION

1.1. OBJECT

The RF planning of a UMTS network follows the process detailed below :

In a first step, the link budget is calculated for the different services required.

Each resulting link budget is based on conditions and assumptions mainly

provided by the customer.

Then, using the link budget outputs, a cell count is performed, providing an

estimation of the number of sites N needed to guarantee the previous

requirements.

The radio planning of the network is now possible by placing the N sitesgeographically and executing coverage predictions.

The object of this document is to provide a description of field tests that aim at

validating the network RF planning.

These different steps will be shortly describe in the following chapters in order to

understand what can be validated with field measurements and how.

1.2. SCOPE OF THIS DOCUMENT

This document defines tests that are to be performed in the first steps of the network

deployment. These tests are applicable fromV1.0bsince the Radiating iBTS feature is

only available from this release onwards (refer to [4]).

No mobiles are needed since the tests described hereafter are based on Agilent

receiver only.

In the following chapters, we will assume that the propagation models used have

been properly calibrated.

1.3. AUDIENCE FOR THIS DOCUMENT

This document mainly applies to Radio Site Verification and Radio Planning teams.

2. RELATED DOCUMENTS

2.1. APPLICABLE DOCUMENTS


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2.2. REFERENCE DOCUMENTS

[R1] UMT/IRC/APP/0022 UMTS Radio Performance Calculation and Verification

[R2] UMT/BTS/DD/0294 Radiating iBTS in EMOAM

[R3] UMT/IRC/DD/0010 UMTS Agilent Receiver - Post-processing requirements

[R4] UMTS/SYS/INF/0022 UMTS Release 1 Baseline


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3. LINK BUDGET CALCULATION

Like in GSM, the cell count is based on the link budget calculation, which provides, by

translating a maximum allowable path loss into a distance, an evaluation of the typical

cell coverage and capacity (air interface) for a given service and a given type of

environment.

The cell count is then used as an input for the RF planning predictions. Therefore, link

budget validation is an important step of the RF planning verification process.

3.1. THEORETICAL EXPLANATIONS

3.1.1 PATH LOSS CALCULATION

In theory, UL maximum path loss is calculated as follows, for a given service used by

user i :

UL max path loss = UE Tx EIRP BS sensitivity(i) + BS antenna gain Link losses

Where :

UE Tx EIRP : It takes into account the UE antenna gain and UE output

power.

UL Link Budget /Service

/Environment

Cell Size Design /service

/Environment

Coverage Area /

environment

BTS Count

/ Environment

Link Budget

Parameters

Offered

services

Geographical

EnvironmentsAssumed Trafic

loading

Pro a ation Model


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BS sensitivity(i) : BS sensitivity for the service used by the user i.

The BTS sensitivity is calculated with the following formula :

BS Sensitivity(i) = No+ Nf+ Eb/No+ Pg

For detailed information of the above parameters, refer to Annex A. Hereis a short description for each of them :

No is the Noise Floor of the BTS i.e. Gaussian white noise

received in the spreading bandwidth and given by: N0=10log(kBT).

Calculated value is No= -108.2dBm.

Nf is the Noise figure accounts for the degradation of the received

signals Eb/N0 in the reception chain. This is due to the internal

noise created in the BTS and the aerials.

Calculated value is Nf= 3.3dBm.

Eb/Nois the required energy to noise margin for the considered

service. This value is based on Nortels assumption and Nortels

guaranteed value is given here below :

Pgis the Processing gain representing the power difference

between the useful signal in narrow band and the Noise received

in the wide band at the BTS.

Nortels simulated values are :

Services Processing GainSpeech 8 kbps 25,29

Speech 12,2 kbps 23,91

Circuit 32 20.35Circuit 64 17,65Circuit 144 14,20Circuit 384 9,98

Data 64 17,34Data 144 13,94Data 384 9,75

BS antenna gain : The typical value taken into account is 18dBi. For the

UE, antenna gain considered null.

Link losses :corresponds to all supplementary losses introduced in the

transmission-reception chain. This typically includes the losses in the BSreception chain (feeders, connectors,) and the slant losses in case

BLER = 10-1

BLER = 10-2

BLER = 10-1

BLER = 10-2

BLER = 10-1

BLER = 10-2

BLER = 10-1

BLER = 10-2

ch 7,95 kbps 5.63 5.63 5.53 5.53 5.72 5.72 5.72 5.72

ch 12,2 kbps 6.44 6.44 6.35 6.35 6.3 6.3 6.3 6.3

it Data 32 kbps 5.27 5.27 5.72 5.72 5.2 5.2 5.2 5.2

it Data 64 kbps 4.87 4.87 5.32 5.32 4.8 4.8 4.8 4.8

it Data 144 kbps 4.44 4.44 4.56 4.56 4.44 4.44 4.44 4.44

it Data 384 kbps 3.92 3.92 4.7 4.7 4.2 4.2 4.2 4.2

et Data 64 kbps 2.93 3.8 3.15 4.2 3.21 3.85 3.21 3.85et Data 144 kbps 2.65 3.5 2.66 3.77 2.77 3.5 2.77 3.5

et Data 384 kbps 2.3 3.25 2.7 3.78 2.6 3.4 2.6 3.4

Rural

Vehicular B 120 km/h

Dense Urban

Outdoor to Indoor B 3 km/h

Sub Urban


Mean Urban



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cross polarisation antennas are used at the BS (BS antenna uses cross

polarization while UE uses vertical polarization).

BS Rx/Tx losses correspond to the total losses existing between the BSI/O and antenna port. They depend principally on two site

characteristics: The quality of the feeder (its diameter).The antenna height.

Nortels values depends on the antenna height and are :

Antenna height(m)

40 h 35 35 h 25 25 h

BS Rx/Tx cable /connector losses

3 2 1.5

Slant losses 1.5 1.5 1.5

If TTLNA is used, BS Rx cable and connector losses are considered as

null.

3.1.2 UL LINK BUDGET CALCULATION

Based on the resulting UL maximum path loss, we have :

UL link budget = UL max path loss + UTRAN features gain Loss margins

The margins and gains will highly vary as a function of the service and the

environment :

UTRAN features gain : it is a constant value (comes from simulation)

based on soft handover gains.

Loss margins : They tend to reduce the maximum allowable path loss

and take the following parameters into account :

Penetration factor represents the attenuation of the signal inside

buildings and car or train. Typical values used by Nortel are :

Environment Penetration loss Incar loss

Suburban 10- 12 dB 5 7 dB

Urban 12 15 dB 5 7 dB

Dense urban 15 - 20 dB

Body loss accounts for the signal attenuation due to users body.

Nortel typical values are :


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Body Loss for Speech service 3 dB

Body Loss for data services 0-1 dB

Interference margin takes into account the noise rise generated by

users in the cell and in neighbouring cells, for a certain cell load.

The default value considered in the design is 3dB, meaning that

the maximum traffic in the cell is equivalent to 50% of the cell

capacity (N-pole formula).

Quality of service margin, also called shadow margin, allows to

guarantee a given quality of service. Typically 90% for the cell

area reliability. It corresponds to the traditional QoS used in GSM

link budget. It depends on the variations of the non-controlled

elements of the propagation : shadowing, various penetration

characteristics, various environments, fast fading.

For 90% cell area measured in indoor (when relevant) :

Environment MarginRural flat vehicular 3.9 dBRural hilly vehicular 7.1 dBSuburban pedestrian 10.7 dBUrban pedestrian 10.7 dBDense urban pedestrian 10.7 dB

3.1.3 CELL SIZE CALCULATION

Based on the previous UL link budget result, and on propagation models (different

models applied according to the environment), the cell size is calculated for each

service type and :

))(_()(__

etenvironmeninofferedservicesULi

iesizecellMinesizecelldesign=

=

The model that is used is Okumura Hata : Used for rural and suburban environment.

Parameters for this models are the frequency, the base station height and some

correction factors.

Attention : This document described the RF planning verification/validation process

assuming the propagation models used are calibrated.

The cell size calculation is then used for the cell count (ie evaluate the number of cells

needed to ensure the required QOC and QOS over the network).

3.1.4 BS POWER CALCULATION

The aim of the downlink power budget calculation is to determine the required

downlink power per user at the cell edge. This will then determine the required BTS


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configuration (total required power, total required processing capacity). As seen

previously, the cell edge has been determined thanks to the uplink power budget.

Note: UTRANDIM simulations is used for cell count and BTS dimensioning.

The parameters used to compute the downlink power budget are similar to the

parameters used to compute the uplink power budget. The final output will be the

average power per user in the cell for every environment and for every user.

3.2. FIELD MEASUREMENT VALIDATION

As we have seen before, the RF planning process takes number of assumptions into

account. The quality of the cell coverage, cell count or network coverage simulations

highly depends on the margin considered. Therefore, those assumptions need tobe validated.

In the following chapters, we suppose that propagation models used have been

already calibrated carefully.


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4. LINK BUDGET VALIDATION

4.1. PURPOSE

This test aims at determining whether the Link Budget Process has been performed

properly or not. Here is a chart describing this process :

Different environments, so different assumptions are considered in the link budget.

The test will therefore be repeated for each of the following environments:

Macro cell, outdoor vehicular 120 km/h : typical in car applications in rural

areas (motorways and roads).

Macro cell, outdoor to indoor suburban : for pedestrian applications in

residential or low urban areas.

Macro cell, outdoor to indoor urban : for pedestrian applications in cities.

Macro cell, outdoor to indoor dense urban : for pedestrian applications in

city centres.

Compute the Reverse Path Loss

Apply reverse system, radio and

traffic margins to the Path Loss

Derive the available reverse Link

Budget

Using the forward link budget

parameters, Derive the forward linkrequired power at uplink coverage

Using appropriate propagation

models, translate the reverse link

budget into a cell size /

service/Environment


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And eventually for :

Macro cell, outdoor vehicular 250 km/h : typical in train applications in

rural areas.

Micro cell, home indoor : for resident indoor usage.

Pico cell, business indoor : for company indoor usage.

4.2. THEORETICAL EXPLANATIONS

This test should provide results allowing validating both link budget assumptions and

propagation model by comparing field results and theoretical computations.

this means link budget calculation and RF simulation tools should be

available in order to provide the required theoretical results.

The validation method is divided in two steps :

1. Simulations : the link budget tool is used to calculate maximum path loss.

The parameters inputs (type of traffic, load, ) to this calculation are the one

being considered on the network for the field tests.

2. Field tests : received signal (RSCP) measurements are recorded on the field

and post-processed in order to be compared to the previous simulations.

We know that :

UL link budget = UL path loss + UTRAN features gain Loss margin

The UTRAN features gain is null since there is no power control on the pilot and no

soft handover possible (test is done for a single cell at a time). Therefore, if we

consider the link budget is balanced :

UL link budget = UL path loss Loss margin = DL link budget

Knowing the BTS output power, the antenna gain and the cable losses, the DL link

budget will be given by the difference :

DL link budget = pCpichPower + antenna gain link losses - RSCP

Our goal is to verify that the target quality of coverage Xis reached, or that for X% of

the cluster area, the required service is available and the target QOS ensured. It is

equivalent to check that for X% of our measured samples, the corresponding link

budget is greater than the theoretical link budget at the edge of the cell.

Therefore, we will measure the received signal RSCP within the cell, calculate the link

budget for each sample and evaluate the percentage of sample for which link budget

value is greater than :

DL link budget limit = UL maximum path loss Loss margin


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We can compute Cumulative Distribution Function of the DL link budget such as :

4.3. SIMULATION

For each considered environment, and for a particular target QOC, a link budget is

calculated and maximum UL path loss determined taking into account :

a single BTS,

no traffic but only the pilot transmitting at power P,

no interference from other users or BTSs,

no soft handover possible,

Parameters used in the field (BTS pilot power, LNA,...).

Then, simulation are done and the cell coverage determined according to the

propagation assumptions and for a particular environment.

This process allow to draw a map providing the theoretical geographical cell coverage.

4.4. FIELD VALIDATION TEST

As seen previously, the same test procedure has to be applied for different

environments. Moreover, considering a particular environment, the test must be

repeated for different BTSs in order to have a sufficient amount of data and then

relevant statistics.

Using the map created during the previous phase (see previous chapter), the drive

test routes can be prepared : the measurements shall always be done within the

theoretical cell coverage area.

DL Link Budget distribution - Urban environment

0

20

40

60

80

100

120

Link Budget values (dB)

Numberofsamples

0.00%

20.00%

40.00%

60.00%

80.00%

100.00%

Distribution Cumulative Distribution


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Pre-requisites:

Link budget and cell coverage simulation (ie outputs described in chapter 4.3)

The iBTS feature radiating mode (refer to [R2]) must be available i.e. the pilot

and the synchronization channels must be transmitted,

BTS configurations need to be checked to detect singularities such as LNA or

other H/W particularity that may impact the link budget parameters.

Tools:

Agilent receiver,

Agilent post-processing tool.

Configuration and Parameters :

For each test, only one BTS is radiating,

The pilot power is set to the BTS power used in the link budget.

Procedure:

1. Routes covering each cluster must be determined. These routes should always be

within the coverage area specified by the simulation.

2. The RSCP is measured with the Agilent receiver.

A sufficient number of samples should be recorded in order to give relevant

conclusions.

Outputs & Results Processing:

For each geographical location (cf binning notion in [R3]), the following outputs are

provided :

2

2

Cell 1


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o Map of colour-coded RSCP,

o DL link budget (CPICH power RSCP),

Statistics are also provided (also considering a geographical binning, refer to [R3]):

o DL link budget distribution/Cumulative,

Considering the target QOS X, we will verify that for X% of the measuredsamples, the corresponding link budget is greater than the theoretical link

budget limit.

The theoretical and measured path loss can be compared on the maps and ifsignificant differences are noticed, a warning should be given.


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5. PILOT AND NEIGHBOURING VALIDATION

5.1. PURPOSE

The purpose of these tests is to :

1. Validate the quality of coverage of the pilot channel as well as the pollution of

other pilots. In parallel it will help at determining whether Nortels

recommended pilot power value is relevant or not.

2. Verify that the neighbouring list for each cell is exhaustive.

Pilot coverage provided by the design will be evaluated and for areas lacking sufficient

coverage, a redesign of the network should be recommended as :

Additional down-tilt or reorientation of antenna with narrower beam-width. It

should solve some problems and decrease interference.

Change of antenna type or height some simple problems of interference pollution.

site addition that might provide a capacity relief for some overloaded sectors.

Addition of a second carrier overlay in order to provide the additional capacity in

urban area.

For the neighbouring list validation, the network configuration (DRF of iPlanner) is

used to list the neighbours configured by the operator.

5.2. VALIDATION TEST

The test is the same for each type of validation (pilot coverage, pilot pollution or

neighbouring list). It consists in using the Agilent receiver to measure the CPICH

Ec/No for all scrambling codes decoded.

The CPICH Ec/No is the received energy per chip divided by the power density in the

band i.e. it is identical to the RSCP measured on the CPICH divided by the RSSI.

Pre-requisites:

The iBTS feature radiating mode (refer to [R2]) must be available i.e. the pilot

and the synchronization channels must be transmitted.

Tools:

Agilent,

Agilent post-processing tools.


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Configuration and Parameters :

All BTS must be in radiating mode.

The CPICH and SCH powers must be set to the Nortels recommended relativevalues.

Procedure:

The procedure is the same as the one described in previous chapter (see chapter

Erreur! Source du renvoi introuvable.) except that more than one BTS is radiating.

Therefore the drive test routes will be different.

Outputs & exit criteria:

The Agilent post-processing tool offers different functionalities (refer to [R3] for more

details) :

o SC plotter : The objective is to verify the coverage of each scrambling

code.

o System map : It allows filtering the best scrambling codes in term of

Ec/No and provide all available measurements for each geographical

position.

5.2.1 PILOT COVERAGE

Ec/No measurements give information about the pilot QOC (Quality Of Coverage).

2

2 2

Cell 2

Cell 1Cell 3

Cell 4


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The Pilot Ec/No plot displays the best server pilot-to-interference ratio over the

coverage area. Pilot Ec/No is used extensively in the call origination and handoff

process.

Based on Nortel Networks' experience in IS95, Pilot Ec/No -12 dB is needed to

achieve a good grade of service. But it is up to the test operator to decide what will be

this threshold Y.

The validation objectives will be to check the measured Ec/No is higher thanthreshold Y, in each location of the tested area. It will be done using the

System map (screening by best Ec/No) of the Agilent post-processing tool.

5.2.2 PILOT POLLUTION

When the active set is filled with cells having equivalent Ec/No, then may appear what

we call the pilot pollution. It is usually a RF planning mistake leading to large overlaps

between cells.

Using Agilent post-processing tools features (number of cells in the active set, SC

plotter), this possible issue may be detected.

The first feature allows counting the numbers of cells with Ec/No at most x dB (Delat

threshold) lower than the best cells Ec/No. The chart below gives an example :

The validation will consists in verifying the coverage of each scramblingcode, using the SC plotter feature. For example, lets take the case where 4

cells have with equivalent Ec/No have been detected with the previous

analysis. This second feature will be useful to identify the overshooting cells

for which their Ec/Io strength is strong enough in areas where they are not

Ec/Io

Frequency

5 MHz

1 W-

451945

-3

-7-9

-15

-8

Here, only 2 SCs have anEc/Io within 5dB of theStrongest Ec/Io (-3dB).

Their Ec/Io is above thestrongest 5dB i.e. 8dB.

Threshold=5.

SC above5) will be

unted


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intended to provide coverage. In such cases, the antenna configuration of

these cells will need to be modified to control the RF coverage.

5.2.3 NEIGHBOURING LIST

The list of possible neighbours is provided to the system by the operator at the OMC.

The validation will consist identifying the missing neighbours by comparingthe neighbour list (see the network configuration and the DRF of iPlanner)

with the Top N measurements of the Agilent receiver.


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6. ABBREVIATIONS AND DEFINITIONS

6.1. ABBREVIATIONS

CPICH Common Pilot Channel

DL DownLink (or forward link)

DRF Data Request Form

Ec/Io Received energy per chip divided by the power density in a W-CDMA carrier band

MS Mobile Station

QoS Quality of Service

RSCP Received Signal Code Power

RSSI Received Signal Strength Indicator (in dBm)

SC Scrambling Code

SIR Signal to Interference Ratio

UE User Equipment (mobile)

UL UpLink (or reverse link)

6.2. DEFINITIONS

Visual BBS R&D tool that is plugget onto the iBTS and allows the user to retrieve internal

measurements such as radio measurements (RSSI, code power,) or BER,

BLER.

END OF DOCUMENT

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