pre launch optimization

3G-Pre launch Optimization

Contents

1. Introduction 2. UMTS technology in brief 3. Pre-Launch Optimization 4. Phase 1: Site Verification 5. Phase 2: Cluster tuning 6. Phase 3: Market Area Tuning 7. Phase 4: Inter RAT Handovers 8. Appendix 8.1. Site Verification Form Sample 8.2. Definitions 8.3. References

Introduction

Pre-launch optimization basically deals with assessing a newly-built network, uncovering problems and resolving them prior to commercial launch. It entails detailed field rf measurements, detecting and rectifying problems caused by radio, improper parameter settings or network faults and finally, grading the radio access part of the network to make sure that it passes certain evaluation criteria

UMTS technology in brief

Architecture UTRAN Interfaces


Wideband CDMA is the recognized air interface standard for 3G-UMTS

WCDMA utilizes the spread spectrum technology for radio access where users are identified by unique codes

For optimal operation of the wireless system, several functions are in place to control the radio network and the many active handsets


Efficient power control in both directions regulates the over-all interference level which is very important in a network with a frequency reuse of 1

“Cell breathing” is a phenomenon inherent in WCDMA. This is the trade-off between coverage and capacity where the size of the cell varies depending on the current load.

Macro-diversity is another feature of the network which is achieved during soft handover. A user can be connected to two or three base stations at a time providing a more reliable connection, thus reducing the risk of premature disconnection

Architecture

For mobile network operators like Airtel, Vodafone that has an existing GSM infrastructure, the migration scheme towards 3G primarily involves annexing a UMTS Terrestrial Radio Access Network (UTRAN) to the current setup. Both the GSM BSS and the UTRAN are connected to the same core network which handles all voice and data traffic from both systems, in circuit-switched (CS) or packet-switched (PS) modes

Architecture and Interfaces

Pre-Launch Optimization

Objective Phases of pre-launch optimization

Objective

In a nutshell, the main goal of pre-launch optimization is to make the UMTS network ready for commercial launch. To achieve this, a series of tests and tuning methods must be carried out and repeated as many times as required in order to meet certain performance criteria. Tests will basically start from cell level and then progressively widen in scope to encompass larger groups of cells until the entire market is tested as one functioning unit

Phases of pre-launch optimization

Phase 1

Site Verification

Phase 2

Cluster Tuning:Unloaded and Loaded Cases

Phase 3

Market Area tuning

Phase 4

I-RAT Test Network Launch

Phase-1& 2

Phase 1 testing is needed to check if the Node- B is able to perform all the vital functionalities and if its coverage conforming to the site rf design. Every Node B in the network has to pass this test.

Phase 2 will be done at cluster level and will consist of two sub phases:

Unloaded scenario – involves testing a “quiet” network aimed mainly at optimizing Layer 1 performance. At this time Neighbor Lists tuning will typically be done.

Loaded scenario – with more rigid tests to evaluate the major services. In this phase, artificial load will be introduced to simulate real subscribers

Phase-3&4

Phase-3 is similar to Phase-2 in a loaded configuration but on a geographically wider scale to encompass the entire Market area., and confirm inter cluster operation.

The last phase will involve handover tests between the two Radio Access Technologies – the existing GSM and the new UMTS networks.

Site Verification

Objective Inputs Log File Naming Convention Entry Criteria Tool setup and test process Analysis Change requests Exit criteria Deliverables

Objective

Site verification aims to guarantee that each cell is performing according to specifications. Both coverage and functionality tests will be performed to evaluate every cell in the network.

At the end of the exercise the RF engineer should be able to:

Detect the possible causes if the coverage levels are too low Verify correct antenna orientation and fix swapped sectors, if any. Ensure that basic cell functionalities execute properly Check for uplink interference Document and compile log files and test sheets for each site tested.

These can be useful references, especially while doing cluster tuning Datafill verification

Inputs Log File Naming Convention Entry Criteria

Tool setup and test process

Upon arrival at the site, an attempt to validate

as much site information as possible should

be made. Perform a basic site audit to verify

the following: Antenna location Antenna type height Azimuth Mechanical tilt


A stationary test to be performed under the best possible radio conditions within the cell area will consist of the following:

In Idle mode, verify the PSC, Cell ID, LAC & RAC (displayed in SIB 1) of the test sector is correct

Test the following call scenarios in each sector: MO (mobile originated) to a landline number MT (mobile terminated) to a landline number MM (mobile-to-mobile) calls CS Video calls PS Call FTP downloads of various sized files, ping tests, web page

browsing HSDPA FTP downloads of various sized files, ping tests, web page

browsing Confirm that CPICH RSCP, CPICH Ec/No, UE Tx Power, BLER,

session application throughputs are within acceptable ranges


A drive test should then occur to test the following:

Test softer HO in both clockwise and counter clockwise directions around the site

Check soft HO to neighboring site (if relevant) Check IRAT to neighboring site (if relevant

Analysis

Basically, the RF engineer should ensure that all functionality tests are successful.

Proper call setup and termination within acceptable call setup times

No dropped calls - except due to loss of coverage.

No failed Soft and softer handovers Packet service data rate - at very close

proximity from the site, it should be easy to achieve 384kbps DL throughput

Analysis

Coverage analysis involves a visual comparison of the actual and planned coverageplots. Naturally, the two plots should more or less be the same. Large discrepancies can mean many issues such as:

Propagation modeling via the planning tool is either extremely pessimistic / optimistic in presenting the coverage propagation for a cell

Site issues such as faulty radio and antenna equipment. Non-optimal antenna placement may lead to blocked antennas reducing

coverage. Inaccurate Azimuth settings set / revised during deployment Faulty test equipment could be used to incorrectly measure coverage criteria. Parameter settings such as overhead channel power settings could be incorrect. It is the RF engineer’s role to pinpoint the causes of the problem and develop

the necessary solutions. One abnormality that is easily detected via a coverage drive-test is swapped

feeders. Feeders terminated at the wrong antennas are commonplace in new site implementations and this is the best time to detect and correct this kind of problem. Be aware that swapped feeders on the receive path, if possible, will exhibit unacceptable TX / RX level mismatches.

Change Request & Exit Criteria

A system for issuing change requests should be in place to fix any hardware and parameter discrepancies found during the activity. Fixes may involve difficult hardware repairs / parts replacement in the site or simple parameter changes at the NMC, like neighbor additions. Verification tests should follow afterwards to make sure that change request was implemented properly.

Site verification is considered complete for a Node B if all functionality tests are successful, site coverage meets design objectives and there are no unresolved installation faults.

Deliverables

Planning tool Pilot RSCP plots for each sector Drive-test Pilot RSCP plots for each sector Drive-test Pilot Ec/No plots for each sector Drive-test UE Tx Power plots for each sector Drive-test Application Layer Throughput plots

for each sector Site Verification checklist Change Request checklist

Cluster Tuning

Tuning a large network composed of thousands of sites calls for the old divide-and-conquer principle. This exercise is called cluster tuning, wherein the entire RNC area is divided into manageable pieces, investigated and then optimized one by one.

Objective

The UMTS KPI document strictly sets the levels of performance that have to be met prior to a network launch. For cluster tuning purposes, a set of KPIs covering voice and packet data services were selected and presented in next slide. The UMTS KPI document specifies targets to be achievable in both unloaded and loaded conditions in the pre-launch phase.

Cluster Acceptance KPIsCRITERIA KPI NAME

CSV Accessibility CSV Access Failure Rate

CSV Setup Time CSV Call Setup Time

CSV Retainability CSV Drop Rate

CSV Quality CSV Quality (BLER)

CSV Resource Allocation CSV Soft/Softer Handover Overhead

PSD Accessibility PSD Access Failure Rate

PSD Retainability PSD Drop Rate

PSD Throughput PSD DL / UL Throughput per RAB

PSD Setup Time PSD Session Activation time

CSD Accessibility CSD Access Failure Rate

CSD Setup Time CSD Call Setup Time

CSD Retainability CSD Drop Rate

CSD Quality CSD Quality (BLER)

HSDPA Metrics PSD Throughput, setup and failure rate

Cluster Tuning ProcessPreparation (Drive Route,

Neighbors, Cluster Definitions)

Drivetest (Unloaded network)

Post-processing & Analysis

Documentation

Formulate & Implement Change proposals

Exit criteria

met?

Y

N

Drive test (Loaded network)

Post-processing & AnalysisFormulate & Implement

Change proposals

Exit criteria

met?

Y

N

Process F

low C

hart

Preparation

Information database

The RF engineer will need various information about the network in allstages of the cluster tuning process. To start with, a site databasecontaining at least the following physical information should be in order.

Site location Sector azimuth Node-B type Antenna height Antenna type Antenna mechanical tilt Antenna Variable Electrical Down Tilt (VEDT) remote control capability Antenna sharing Feeder length Jumper cables Diplexer / Duplexer / TMA equipment

Information database cont’d

Panoramic photos taken during the site survey are also excellent references whereupon tuning changes will be based later.

It is also important that actual RAN parameter information is always available. This includes cell parameters, neighbor lists, actual antenna tilt which can be retrieved remotely at the NMC. Information can change on a daily basis so it is important to keep past records in a database to be able to view the history of changes that have occurred.

A planning tool with a properly tuned propagation model will provide simulation results at unloaded and loaded configurations. Coverage and interference predictions generated from the planning tool will be used as references for preparing the drive test route and for identifying potential problem areas. The tool is also a means to verify the effect of tuning solutions before actual implementation. For the actual pilot coverage of each cell in the cluster, one may refer to the data collected during the site verification drive test.

Neighbor Generation

This task should aim to create an optimal set of 3G 3G and 3G 2G neighbor relationships. Since neighbor optimization is an evolving activity, constant monitoring via performance metrics and correlation between neighbours actually loaded in the system and those that RF Engineers have specified needs to occur. The steps involved with neighbor generation could be summarized as follows:

Use Asset 3G or other planning tools to come up with an initial neighbor list for 3G to 3G neighbors ranked by priority

Run a consistency check to ensure all neighbors defined are reciprocal. Also ensure that the maximum number of neighbor list for a particular cell has not been reached

Run a consistency check to ensure that co-scrambling code reuse does not exist up to 2 tier neighbours away

Neighbor Generation Cont’d

Use either Asset 3G, other planning tools with GSM neighbour definitions to come up with an initial IRAT neighbor list

If available, consult with each RF Engineer with local knowledge about the neighbor definitions

Instruct NMC / UTRAN personnel to add neighbors for sites / clusters into the RNC

Perform a manual / automated check of neighbors loaded in the RNC versus those designed to ensure correct neighbor definition exists

Add any new neighbours found during cluster and market tuning exercises

Use OSS Neighbour tools to optimize neighbours and increase system performance and KPIs

Drive Test RouteThe clusters will be drawn such that all areas within the market or service area are included in a

given cluster. The goal of the drive routes should be to ensure that all areas within a given cluster are thoroughly tested. Listed below are some considerations when planning the drive test route:

All cells should be driven through –the performance of every cell should be measured as well as the handovers to and from every cell.

Dive all the necessary primary, secondary and neighborhood roads – where applicable, consider commuter ferry routes, rail lines etc as part of the route.

In the case of downtown areas – expect to drive every street in these areas.

The route should be evenly spread out across the cluster area – it should consist of a variety of distance and bearing points with respect to the sites. An even route distribution across the cluster ensures that subsequent statistical inferences are representative of that area as a whole.

Minimize duplication of routes – this will make post analysis more convenient especially when replaying log-files to zero in on particular call events

Explore potential pilot pollution / low coverage spots – refer to planning tool simulation plots of best server Ec/No & RSCP to locate the potential trouble areas.

For the purpose of stationary or In Building test purposes - anticipated hotspots like commercial complexes, stadiums, train stations and airports should be identified.

Pilot Test Scan

GSM coverage is measured in terms of BCCH signal strength with the use of a scanner that is tuned to the correct frequency. In UMTS, this is done by measuring the received signal level of the pilot channel after despreading; in other words, the CPICH RSCP which stands for Common Pilot Channel Received Signal Code Power. There is one pilot in every cell transmitting at a constant level all the time.

Essentially, a scanning receiver will take two measurements: RSSI or the total downlink wideband power and the RSCP of each detectable pilot. From these two measurements, a third parameter which is the signal quality or Ec/No of each pilot is calculated with the simple formula, RSCP/RSSI. Since RSSI is actually the combined power of all the pilots including the wanted pilot signal itself plus thermal noise, then Ec/No always turns out to have a negative numerical value.

Pilot Test Scan Cont’d

The pilot test scan process allows neighbor list analysis and should easily pick up major neighbor list omissions. In some cases it can also be used to determine neighbor relationships that are not really relevant. This process is required if neighbor lists become too large to be well managed by the vendor specific composite neighbor list generation algorithms. The issue occurs when soft handover is entered and each active set member has its own neighbor list, hence some rules are followed to determine the new “composite” neighbor list.

CSV Test

Two UMTS handsets will test circuit-switched voice service. They should be configured to operate as follows:

1 UE for Long call continuous AMR voice call (MOC) to the system test number carrying

voice information redial waiting time of 10 seconds after a dropped call or call setup

failure, if encountered; this is to allow the phone to fully return to idle mode

applicable KPI: CSV Quality (BLER) 1 UE for Short call

AMR voice (MOC) to the system test number carrying voice for 90 seconds

150 seconds idle period between calls 10 seconds waiting time before retry in cases of call setup failure or

dropped call applicable KPI: CSV Access Failure Rate, CSV Call set up time, CSV

Drop Rate, CSV Quality (BLER)

PSD Test

Two UEs will test packet-switched data service and should be configured to operate as follows:

1 UE for PS data call downlink transfer PS data call to download 2 / 10 MB data block from an FTP server 10 seconds waiting time from RRC connection release to the next RRC

connection setup redial waiting time of 10 seconds after a dropped call or call setup failure, if

encountered 32 byte Ping measurement every 30 seconds Applicable KPI: PSD Access Failure Rate, PSD Drop Rate, PSD Latency, PSD

DL Throughput UE Mobile per RB, PSD Call Set up time

1 UE for PS data call uplink transfer PS data call to upload 3MB data block from an FTP server 10 seconds waiting time from RRC connection release to the next RRC

connection setup redial waiting time of 10 seconds after a dropped call or call setup failure, if

encountered Applicable KPI: PSD Access Failure Rate, PSD Drop Rate, PSD UL Throughput

UE Mobile per RB, PSD Call Set up time

Drive Test Speed

To simulate actual subscriber driving conditions and ensure evenly distributed data points, the following vehicle speed ranges must be observed. However, note that all times, drivers must not exceed the speed limit and must follow all signed markers.

Urban and dense urban15 to 20 mph Suburban 30 to 40 mph Rural and Highways60 to 80 mph

Measurement repeatability

In any field measurement exercise, it is vital that the tool is set up to allow forrepeatable and accurate measurements. The goal is to minimize, if not eliminate, the possible sources of inconsistencies by taking the following Measures:

Use of external antennas for all UEs; otherwise, UE performance could vary relative to its position inside the vehicle

Ensuring all RF connections are tight and secure to guarantee accurate measurements. If any cables or connectors are deemed to be damage, they should be promptly replaced

Calibrate all scanning receivers to get precise and uniform readings Maintain adequate RF separation between the GPS, scanning receiver

and UE external antennas on the car roof by placing them at least 2 wavelengths apart (28 cm. for 2100 MHz)

As the devices may affect each other’s RF behavior if positioned side by side inside the vehicle, it is suggested that they are spaced properly or placed in individual rf isolation boxes, if available

Use the identical drivetest vehicles for all teams with a clean accessory-free top for mounting the antennas

Unloaded Test The first step in tuning a brand new live network is to conduct

tests in an unloaded configuration. By definition, an unloaded network is one where only the common channels are being transmitted by the base stations.

This section defines procedures to be used for cluster testing & optimization under no load or minimum load conditions (no appreciable traffic in the network). The unloaded pilot survey results identify coverage holes, handoff regions, multiple pilot (pilot pollution) and non-dominant coverage areas. The pilot survey information highlights fundamental flaws in the RF design of the cluster under best-case, lightly loaded/unloaded conditions. The pilot survey provides coverage maps for each sector in the cluster, these coverage maps are used to adjust antenna, azimuth, tilts, transmit powers and neighbor lists. Measuring the pilot levels without load serves as a baseline for comparison with measurements from subsequent cluster tests under loaded conditions.

Optimization Objective with Unloaded Test

Ensure that acceptable coverage is achieved from the common and traffic channels

Ensure there are no evident drop calls Ensure optimum Soft Handover areas and pilot

dominance Compare the RF predictions with actual

measurements Check the accessibility, reliability & quality under

vehicular environment. Neighbor list tuning Meet CSV KPI targets

Poor Coverage Issue

Problems related to poor coverage may be tackled in several ways. In order of priority, they are as follows:

Verify the downtilts implemented at the site and determine whether they are actually necessary. If not, use the planning tool to see if the downtilts can be reduced to improve coverage. Reducing downtilt, however, must be implemented with caution: it should not be performed at the expense of ‘non-containment’ related problems caused elsewhere. One has the option between mechanical and electrical tilts, or a combination of both, to achieve the desired result. With the use of remote – remote tilting features, the electrical tilt can be conveniently monitored and adjusted via a terminal at the NMC in real time, at any time of the day. Changing the mechanical tilt, on the other hand, still requires deploying riggers to the site.

Change the antenna azimuth to focus the main lobe where desired Change the antenna type to provide more gain or a narrower beamwidth is

desired Increase the antenna height of the serving cell Increase the CPICH power setting – check design limitations for minimum and

maximum settings. The total power allocation for the common channels should not exceed the set limit to leave ample power for traffic

Lack of DominanceWhen the problem is lack of dominance brought about by overshooting cells, too many strong servers, adjacent cells with excessive overlap or stray signals resulting from reflections, back

lobes or side lobes, a different approach is taken. Again, according to priority, tuning can be done by:

Down tilting the antenna of the interfering cell either electrically or mechanically – when doing mechanical tilts, be aware that the back lobes and side lobes may become aggravated leading to more problems. Be careful about opening up coverage holes especially indoor when downtilting. Tilting can be done in steps of 2 to 5 degrees depending on the severity of the interference.

Changing the antenna bearing of the cells that contribute to pilot pollution.

Changing the antenna type of the cells that contribute to pilot pollution, e.g., higher gains for the server, lower gains for the interferer.

Increasing the antenna height of the server and reducing that of the interferer

Changing the CPICH power setting – increase the serving cell’s transmit power and/or reduce that of the interferer

Note: the preference is to control RF by exhausting all the possible hardware modifications first before changing the pilot power. Any variation in pilot power produces a proportional effect in the maximum power allocated by the cell for dedicated channels

Layer-1 AnalysisMeasurement Plot What it shows What to look for

Best server RSCP measured CPICH RSCP level (in dBm) of the strongest serving cell

Any area with RSCP of less than this design threshold is considered a weak coverage area. The RF Planning Guidelines requirement for in-car RSCP for AMR voice is -100 / -99 dBm. (Vendor specific)

Best server Ec/No measured CPICH Ec/No level (in dB) of the strongest serving cell

CPICH Ec/No is the most important measurement in WCDMA for network planning and optimization purposes. It is theoretically equal to RSCP divided by the total wideband received power (RSCP/RSSI). Low Ec/No is the result of interference and poor dominance. Because the measurements were made under unloaded conditions, they represent an ideal, best-case condition. Under fully loaded conditions, observed pilot Ec/No levels would be lower than the unloaded measurements. Any coverage holes, which exist for the unloaded measurements will be worse once the system matures and becomes loaded.

Best server SC Primary Scrambling Code of the strongest pilot

Cells that cover a much bigger (or much smaller) area compared to its neighbors. Cells that overshoot beyond the target service area. This plot gives an idea about how well or how bad the coverage of a certain cell is contained.

Per-SC RSCP / Ec/No

measured CPICH RSCP and Ec/No level (in dBm and dB) for a specified scrambling code

Overshooting cells. Cells with very low RSCP or Ec/No within its target service area. SC clashes – identical primary scrambling code being used by cells without sufficient spatial isolation.

4th best server RSCP

measured CPICH RSCP level (in dBm) of the 4th strongest serving cell

Strong 4th best server RSCP, say greater than -95 dBm – a potential pilot polluter.

Number of measured SC

number of detected pilots above a defined RSCP threshold

Number of strong SC > 3. This plot is another way of looking for excessive number of strong pilots. An RSCP threshold of say -95 dBm may be defined.

UE Tx Power Measured UE Tx Power level (in dbm)

Areas where the UE is transmitting at a higher power due to increased uplink interference, UE issues, hardware issues related to NodeB, TMA, antenna systems.

Soft Handoff / Inter-Frequency / IRAT

Measured area where handoff activity is occuring

Identify areas where soft handoff / inter frequency or IRAT hand-downs are occurring.

Voice Call Analysis (Dropped calls and Call setup

failures

The causes for the failures can be classified into three groups: RF planning-related, network-related and tool-related. Technically, job of the RF engineer may be limited to fixing only those that fall in the first category but the rest still need to be properly documented and referred to the concerned departments for their action.

RF Planning problems

Inadequate downlink coverage, poor dominance, pilot pollution

Inadequate uplink coverage, uplink interference

Missing or one-way neighbors Rapid field drop Slow handovers Scrambling Code interference

Loaded Test

The performance of the cluster is affected by the amount of traffic load it is carrying. For one, the effective coverage shrinks as the level of the noise generated by the system rises. The objectives of the loaded test are: Assess network performance at the amount of load

for which it was designed Fix the additional Layer 1 problems that appear when

the network is under load Perform a more intensive optimization campaign to

meet CSV, PSD and CSD Video KPI targets in a loaded configuration

Market Area Tuning

Market area tuning is essentially the same as cluster tuning but on a literally larger scale to gather data from several clusters working together. The entire Market area now becomes one single cluster. Below are the objectives of this phase: Assess the over-all performance of the radio network

from Market level Test inter-RNC handovers Identify new problems that degrade the network Devise tuning solutions for the new problems Meet performance KPIs at Market level Make the RAN commercial launch ready

Inter RAT Handovers

Following are the possible instances of Inter RAT handover requirement in the network. The information about the possibilities of these instances should be obtained by the engineer in order to develop a drive test plan for IRAT handovers. The approach for the UMTS network deployment is to start the rollout

from the core areas and extend outward progressively and to match the EDGE footprint. Thus the UMTS coverage area would be a sub set of that of GSM.

For several reasons like, inability to install UMTS Hardware, interference issues in the out door network (may just apply to very dense GSM presence area like ,Connaught Place, New Delhi), etc. the rollout of the UMTS network may not be 1:1 for those specific areas.

Effect of loading (cell breathing) on UMTS may result in the weaker coverage area of UMTS network with respect to that of GSM.

Presence of in-building coverage may be different for GSM and UMTS due to existing GSM in-building solutions and ability to pump RF towards the buildings in GSM.

Inter RAT Handovers Cont’d

Thus from the IRAT handovers point of view following objectives of the pre optimization check needs to be considered. IRAT boundary should not fall in the high traffic / high mobility

area. Parameters should be set in such a way that UMTS capable

UE’s stay on UMTS until acceptable quality can no longer be sustained

Success Rate of IRAT handovers should meet the target KPI. Performance impact of IRAT handovers/reselection on all the

bearer services should be taken into account. IRAT in UMTS area will be equivalent to a drop and hence

should be optimized to only trigger to maintain the quality/ continuity of the call whilst meeting the planning criteria.

Inter RAT Handovers Cont’d

Following is required to meet above mentioned objectives. Detailed drive test to clearly define the UMTS

coverage area boundary in terms of RSCP and Ec/Io levels.

The significant patches of absence of UMTS RF need to be marked clearly.

Thorough analysis of loaded and unloaded drive data to point out potential creation of IRAT boundaries due to loading.

Pointing out major traffic carrying buildings like airport, big malls having weak presence/absence of UMTS RF

RF SITE CHECK SHEET Site Name

Tested by:

Address Cluster Area

Date:

PASS / FAIL PASS / FAIL PASS / FAIL

Sector-1 Sector-2 Sector-3 Comment

CELLId

Antenna Az (TN)

)

Scrambling Code

Confirmed

CS 12.2 kbps MO Call

CS 12.2 kbps MT Call

CS 12.2 kbps MM Call

CS 64 kbps MM Call

PS DL 64/128/384kbps data call

HSDPA data call

Ec/No (dB)

RSCP (dBm)

Est. Dist. From Cell (ft)

Tx Pwr (dBm)

Packet (Application Layer) Througput (kbps)

Log Files

Log Files

Draw handovers tested: Logfile:

Additional comments

Contacts for integration:

RNC:

Definitions

Acronym Term Definition

AMR Adaptive Multi Rate Speech coding scheme used in the UTRAN BCH Broadcast Channel As defined in 3GPP 25.211 BLER Block Error Rate As defined in 3GPP 25.215 CDR Call Drop Rate KPI for network retainability CN Core Network Network subset consisting of MSC, SGSN and auxiliary

equipment CPICH Common Pilot Channel As defined in 3GPP 25.211 CSD Circuit-Switched Data Data transmission using a dedicated channel CSSR Call Setup Success Rate KPI for network accessibility CSV Circuit-Switched Voice Data transmission using a dedicated channel DGPS Differential Global Positioning

System GPS made more accurate by using ground-based beacons

DL Downlink Node B transmit, UE receive Ec/No Received energy per chip divided by the power density in the

band; mathematically equal to RSCP/RSSI; also referred to as Ec/Io

FTP File Transfer Protocol Commonly used protocol for exchanging files over a TCP/IP network like the internet

HHO Hard Handover Handover between two cells involving momentary interruption in the radio connection

IS-95 2G CDMA standard with 1.25 MHz bandwidth KPI Key Performance Indicator Criteria for LNA Low Noise Amplifier Rf amplifier typically mounted on or close to the antennas MIB Master Information Block Information sent over the broadcast channel

DefinitionsMOC Mobile Originating Call Call initiated from the UE in question MTC Mobile Terminating Call Call initiated elsewhere and received by the UE in question NMC Network Monitoring Center Network entity overseeing the operation of all other entities in

the network PSD Packet-Switched Data Data transmission in packet network QoS Quality of Service The minimum quality admitted for a service RAB Radio Access Bearer As defined in 3GPP 25.905 RAN Radio Access Network Same as UTRAN RAT Radio Access Technology e.g. GSM, WCDMA RNC Radio Network Controller UTRAN entity controlling the Node Bs and radio resources RRC Radio Resource Control As defined in 3GPP 25.331 RSCP Received Signal Code Power Received power measured on one code after dispreading; also

referred to as Ec RSSI Received Signal Strength Indicator Total wideband received power within the channel bandwidth SC Scrambling Code Code that identifies the cells in the network SHO Soft Handover Handover involving simultaneous connections from UE to

two or three cells SIB System Information Block Information sent over the broadcast channel UE User Equipment Handsets and data terminals UL Uplink UE transmit, Node B receive UMTS Universal Mobile Telephone System one of the Third Generation mobile systems being developed

within the IMT-2000 framework UTRAN UMTS Terrestrial Radio Access

Network Network subset composed of Node Bs and RNC’s

WCDMA Wideband Code Division Multiple Access

Recognized radio access technology for 3G using 5MHz bandwidth in each direction

pre launch optimization

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