Flow chart Radio-Network-Optimization-Guidelines.pdf

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Contents

About This Document.....................................................................................................................1

1 Introduction to Network Optimization.................................................................................1-1

1.1 Triggering Conditions of Radio Network Optimization.................................................................................1-2

1.2 Flow Chart for Radio Network Optimization.................................................................................................1-2

2 Network Optimization Startup...............................................................................................2-1

2.1 Setup of Network Optimization Team............................................................................................................2-2

2.2 Establishment of Network Optimization and Acceptance Counters...............................................................2-2

2.3 Preparations of Network Optimization Tools.................................................................................................2-3

3 Single Site Verification.............................................................................................................3-1

3.1 Single Site Test Preparations...........................................................................................................................3-3

3.2 Single Site Verification Test...........................................................................................................................3-3

4 RF Optimization.........................................................................................................................4-14.1 RF optimization Test Preparations..................................................................................................................4-3

4.2 RF optimization Data Collection.....................................................................................................................4-3

4.3 RF Optimization Data Analysis......................................................................................................................4-4

4.4 RF Optimization Implementation....................................................................................................................4-5

5 Service Optimization.................................................................................................................5-1

5.1 Service Optimization Data Collection.............................................................................................................5-4

5.2 Service Optimization Data Analysis....................................................................................................... ........5-4

5.3 Service Optimization Implementation..................................................................... .......................................5-6

6 Network Acceptance..................................................................................................................6-16.1 Network Acceptance Counters........................................................................................................................6-2

6.1.1 Drive Test Counters...............................................................................................................................6-2

6.1.2 Performance Counters............................................................................................................................6-4

6.2 Contents of Network Acceptance Report........................................................................................................6-5

7 Network Optimization Tools...................................................................................................7-1

7.1 Probe................................................................................................................................................................7-2

7.2 Assistant..........................................................................................................................................................7-2

7.3 Nastar..............................................................................................................................................................7-6

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Tables

Table 2-1 Tools required for radio network optimization....................................................................................2-3

Table 6-1 3G network KPI of the drive test and cell quality test.........................................................................6-2

Table 6-2 3G network quality KPI of performance data......................................................................................6-4

Table 7-1 Functions of the Assistant....................................................................................................................7-3

Table 7-2 Functions of Nastar..............................................................................................................................7-7

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About This Document

Purpose

Radio network optimization adjusts the radio network planning according to principles. Radio

network optimization ensures more economic and reliable operation and enhances network

service quality and network resource use. Radio network optimization also provides experiences

for the future network expansion. This document describes the RAN radio network optimization.

The phases of the radio network optimization are: project startup, single site verification, RF

optimization, service optimization, and network acceptance.

Related Versions

The following table lists the product versions related to this document.

Product Name Version

RNC V200R009

NodeB V100R008

Intended Audience

This document is intended for:

l Network planners

Update HistorySee Changes in RAN Network Optimization Guidelines.

Organization

1 Introduction to Network Optimization

Radio network optimization adjusts the radio network planning according to principles. Radio

network optimization ensures more economic and reliable operation and enhances network

service quality and network resource use. Radio network optimization also provides experiences

for the future network expansion.

2 Network Optimization Startup

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Network optimization startup consists of forming the optimization team, preparing tools, and

determining acceptance counters.

3 Single Site Verification

Single site verification checks the site performance and cell performance. Single site verificationis a self-test of the cell equipment performance. Single site verification guarantees the basic cell

functions (access, call, and handover) before the RF optimization.

4 RF Optimization

The purposes of the RF optimization consists of optimizing the signal coverage, controlling the

noise interference and pilot pollution, and ensuring the proper signal coverage for future service

optimization.

5 Service Optimization

During the service optimization, you can optimize the service and make the network counters

meet the acceptance requirements. The service optimization analyzes the drive test data andperformance data to solve service problems and improve the network counters to meet the

acceptance requirements.

6 Network Acceptance

Based on the performance data and drive test, the network acceptance checks if the optimized

network meets the optimization counters, evaluate the optimized network quality, and display

the network optimization.

7 Network Optimization Tools

Network optimization tools are used for data collection, data analysis and can simplify the

network optimization and improve the working efficiency. The tools that you use during networkoptimization are: Probe, Assistant, and Nastar.

Conventions

1. Symbol Conventions

The following symbols may be found in this document. They are defined as follows

Symbol Description

DANGER

Indicates a hazard with a high level of risk that, if not avoided,

will result in death or serious injury.

WARNING

Indicates a hazard with a medium or low level of risk which, if

not avoided, could result in minor or moderate injury.

CAUTION

Indicates a potentially hazardous situation that, if not avoided,

could cause equipment damage, data loss, and performance

degradation, or unexpected results.

TIP Indicates a tip that may help you solve a problem or save your

time.

About This Document

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Symbol Description

NOTE Provides additional information to emphasize or supplement

important points of the main text.

2. General Conventions

Convention Description

Times New Roman Normal paragraphs are in Times New Roman.

Boldface Names of files,directories,folders,and users are in boldface. For

example,log in as userroot .

Italic Book titles are in italics.

Courier New Terminal display is in Courier New.

3. Command Conventions


Boldface The keywords of a command line are in boldface.

Italic Command arguments are in italic.

[ ] Items (keywords or arguments) in square brackets [ ] are optional.

{x | y | ...} Alternative items are grouped in braces and separated by vertical

bars.One is selected.

[ x | y | ... ] Optional alternative items are grouped in square brackets and

separated by vertical bars.One or none is selected.

{ x | y | ... } * Alternative items are grouped in braces and separated by vertical

bars.A minimum of one or a maximum of all can be selected.

[ x | y | ... ] * Alternative items are grouped in braces and separated by vertical

bars.A minimum of zero or a maximum of all can be selected.

4. GUI Conventions


Boldface Buttons,menus,parameters,tabs,window,and dialog titles are in

boldface. For example,clickOK.

> Multi-level menus are in boldfaceand separated by the ">" signs.

For example,choose File > Create > Folder .

5. Keyboard Operation

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Key Press the key.For example,press Enter and press Tab.

Key1+Key2 Press the keys concurrently.For example,pressing Ctrl+Alt+Ameans the three keys should be pressed concurrently.

Key1,Key2 Press the keys in turn.For example,pressing Alt,A means the two

keys should be pressed in turn.

6. Mouse Operation

Action Description

Click Select and release the primary mouse button without moving the

pointer.

Double-click Press the primary mouse button twice continuously and quickly

without moving the pointer.

Drag Press and hold the primary mouse button and move the pointer

to a certain position.

About This Document

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1.1 Triggering Conditions of Radio Network Optimization

The optimization can be triggered in the phase of network construction or network maintenance.

l Network construction

Radio network optimization adjusts the operational network planning to better the quality

and efficiency of the radio network.

l Network maintenance

If the changes of propagation environment and traffic volume make the network quality

goes worse, the network optimization is triggered and network parameters are modified to

ensure the stable and efficient operation of the network.

1.2 Flow Chart for Radio Network Optimization

The phases of the radio network optimization are: project startup, single site verification, RF

optimization, service optimization, and network acceptance.

Figure 1-1 shows the flow chart for radio network optimization.


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Figure 1-1 Flow chart for radio network optimization

Phase Description

Project

preparations and

startup

According to requirements of the operator for WCDMA network,

discuss and determine the final optimization target. This target is one of

the criteria for network acceptance.

Single site

verification

The radio network optimization group takes part in the optimization

when the site begins to carry service. The site verification includes the

following:

l Verify that the site runs properly and the data configuration is

consistent with the radio network plan.

l Collect the information about the site and the surrounding

environment for the future optimization.

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Phase Description

RF optimization Radio Frequency (RF) optimization ensures the signal coverage in the

network and solves the service problems caused by the RF.

Network optimization is based on clusters. The cluster refers to severalsites belonging to the same NodeB.

The RF optimization bases on drive test data.

The overlapped area should also be optimized.

Service

optimization

Service optimization is based on both the drive test data and the

performance data. Service optimization is a supplement to RF

optimization.

Service optimization solve service problems, such as access failure, call

drop, and handover failure.

Network

acceptance

According to requirements of the operator, accept the whole network.

The network Key Performance Indicator (KPI) should meet the

requirements of the operator.


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2.1 Setup of Network Optimization Team

During the project preparations and setup, you should at first determine the organization and

members of the optimization team.

Figure 2-1 shows the organization of the optimization team.

Figure 2-1 Organization of the optimization team

2.2 Establishment of Network Optimization and AcceptanceCounters

As the goal of the network optimization, the optimization and acceptance counters must be settled

before the network optimization.

For a network with high quality, the following key indicators should be focused on:

l Coverage ratio

l Call drop rate

l Outgoing access ratio

l Incoming access ratio

l Soft handover rate

l Hard handover rate

l Mean throughput ofPacket Switched (PS) service

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Acceptance counters are of drive test data and performance data. The acceptance counters vary

with different types of network.

l For the new network with few users, most acceptance counters are drive test data.

l For a network that has operated for a period and possesses lots of users, the acceptance

counters consists of both drive test data and performance data.

The specific acceptance counters are determined after the discussion with the operator.

2.3 Preparations of Network Optimization Tools

Every optimization team must have at least one set of drive test tools.

Every optimization team must have at least one set of drive test tools, as shown in Table 2-1.

Table 2-1 Tools required for radio network optimization

Tool Function

Software tools

Probe Collecting drive test data

Assistant Analyzing drive test data

Nastar Checking the parameter configuration

Hardware tools

Pilot receiver Receiving signals from WCDMA cell pilot

channel

UE under test Testing WCDMA services

Laptop

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3 Single Site VerificationAbout This Chapter

Single site verification checks the site performance and cell performance. Single site verification

is a self-test of the cell equipment performance. Single site verification guarantees the basic cell

functions (access, call, and handover) before the RF optimization.

The purposes of single site verification are described as follows:

l Through single site verification, the equipment faults can be separated from other problems

during optimization. For example, the call drop and access failure resulting from equipment

fault is different from call drop and access failure caused by network coverage problem.

This differentiation is good for problem location, which can enhance network optimizationefficiency.

l Through single site verification, the personnel can collect the information of site location,

site configuration, and surrounding radio environment for future optimization.

The single site verification procedure comprises test preparation, single site test, and correcting

problems. Figure 3-1 shows the flow chart for single site verification.

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Figure 3-1 Flow chart for single site verification

When all the cells are verified and no equipment fault exists, the single site verification is

complete. The next phase is RF optimization.

3.1 Single Site Test Preparations

During the single site test preparations, you should perform the tasks of checking site status,

checking data configuration, and choosing cell to be tested.

3.2 Single Site Verification Test

During the single site test, check if problems of equipment performance and installation are

present, and then output the test result .


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3.1 Single Site Test Preparations

During the single site test preparations, you should perform the tasks of checking site status,

checking data configuration, and choosing cell to be tested.

The single site test preparations consist of the following tasks:

l Checking site status

Before the site test, prepare the checklist of the NodeBs and their cells and ensure that the

cells are in proper status.

l Collecting and checking data configuration

Before the site test, collect the planned data configuration and the data configuration in the

RNC, and check if the data configuration in the RNC is consistent with the planned data

configuration.

l Choosing cell to be tested

During the equipment performance test, choose the cell whose signal is stronger than its

neighbors.

l Other preparations

The site under test is allowed to transmit power.

Obtain the number of the UE under test.

Check if the UE is a test UE in project mode or a data card.

Check if the UE battery is fully charged.

Print the test forms.

Collect the information of site location, Cell ID, scramble, site azimuth, and antenna

azimuth.

3.2 Single Site Verification Test

During the single site test, check if problems of equipment performance and installation are

present, and then output the test result .

Tasks you should perform during the single site test are as follows:

l Verifying site configuration

Frequency check: check if the frequency of the cell to be tested is consistent with the

planned data.

Scrambling code check: check if the scramble of the cell to be tested is consistent with

the planned data.

LAC/RAC check: check if the LAC/RAC of the cell to be tested is consistent with the

planned data.

l Verifying site coverage

CPICH_RSCP/CPICH_EcIo check around the site:

Check if the CPICH_RSCP/CPICH_EcIo received by the UE is higher or lower thanthe threshold.

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Check the problems of power amplification, antenna and feeder connection, antenna

placement.

Check if the antenna downtilt and azimuth do not meet the planning because of the

environment changes.

l Call test

Voice service dialup test: check if the voice service function works properly.

Video Phone (VP) service dialup test: check if the VP service function works properly.

PS service dialup test: check if the PS service function works properly.


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4 RF OptimizationAbout This Chapter

The purposes of the RF optimization consists of optimizing the signal coverage, controlling the

noise interference and pilot pollution, and ensuring the proper signal coverage for future service

optimization.

The tasks you should perform during RF optimization are as follows:

l Optimizing signal coverage

Optimize the coverage hole to ensure the continuous coverage of the pilot signals.

Optimize the dominant cells to ensure that the area they cover is neither large nor small

and the overlapped areas are clear.

l Optimizing interference

For the downlink, Interference is represented by good CPICH RSCP and poor CPICH

Ec/Io.

For the uplink, an interference problem exists if the NodeB RTWP is high.

Find the interference source and solve the interference problem.

l Optimizing pilot pollution

Pilot pollution means that several pilots exist in the same area without a dominant pilot.

Pilot pollution causes more downlink interference, frequent handovers (cause call drop),

and less network capacity.

Modify the engineering parameters to solve this problem.

l Optimizing other problems

Optimize the neighbor configuration.

Solve the problems of access and call drop. These problems occur during the tests.

Figure 4-1 shows the flow chart for RF optimization.

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Figure 4-1 Flow chart for RF optimization

4.1 RF optimization Test Preparations

During the RF optimization test preparations, you should perform the tasks of determining

optimization target, grouping clusters, determining test course, and preparing tools and

materials.

4.2 RF optimization Data Collection

During the RF optimization data collection, you should gather UE and Scanner data through

drive test, indoor measurement, and signal tracing. You should also gathers call tracing data at

the RNC side and RNC configuration data, and check if the data meet the requirement.

4.3 RF Optimization Data Analysis

Through the RF optimization data analysis, you can locate and analyze coverage problem, pilotpollution problem, and handover failure.

4.4 RF Optimization Implementation

During the RF optimization implementation, you can modify the engineering parameters and

cell parameters to meet the KPIs.

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4.1 RF optimization Test Preparations

During the RF optimization test preparations, you should perform the tasks of determining

optimization target, grouping clusters, determining test course, and preparing tools and

materials.

Tasks you should perform during the RF optimization test preparations are described as follows:

l Determining optimization target

The RF-related KPIs consist of the following items:

Coverage ratio

Soft handover rate

Pilot pollution rate

l

Grouping clustersBecause of the technical characteristics of UMTS network system, such as cell breathing,

frequency multiplexing factor being 1, RF optimization should be conducted on a group of

NodeB sites.

l Determining test course

Before the drive test, determine the test course after a discussion with the operator. If the

drive test acceptance course is determined, the KPI test course should cover the acceptance

course.

l Preparing tools and materials

4.2 RF optimization Data CollectionDuring the RF optimization data collection, you should gather UE and Scanner data through

drive test, indoor measurement, and signal tracing. You should also gathers call tracing data at

the RNC side and RNC configuration data, and check if the data meet the requirement.

The methods of RF optimization data collection are described as follows:

l Drive test

According to planned service type (full coverage), drive test may choose one of the

following tasks:

The continuous VP service test: This test use Scanner and is applicable only to the 3G

network, which does not carry service during the test.

The continuous Voice service test: This test use Scanner and is applicable only to the

3G network, which does not carry service during the test.

The continuous PS384K service test: This test use Scanner and is applicable only to the

3G network, which does not carry service during the test.

l Indoor measurement

Indoor measurement measures the full coverage service. This test is required by commercial

office (with contract) and pilot office (with planning). Its testing method is the same as that

of the drive test.

The indoor measurement is mainly conducted at the following places:

Indoor coverage zone, such as building, mall, and subway

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Places of high importance, such as government building and gym

The test area required by the operator, such as Very Important Cell (VIC) and Very

Important Person (VIP).

Drive test and indoor measurement are two major methods of data collection. Drive test is

mandatory. Indoor measurement is optional according to the contract or planning.

4.3 RF Optimization Data Analysis

Through the RF optimization data analysis, you can locate and analyze coverage problem, pilot

pollution problem, and handover failure.

Coverage Analysis

Coverage analysis is the key part of the RF optimization. The coverage analysis focuses on signal

distribution. Coverage analysis consists of the following activities:l Downlink Coverage analysis

l Uplink Coverage analysis

The common coverage problems are as follows:

l Coverage hole or cells with poor coverage

If the scramble of some cell cannot be detected according to the result of the drive test, it

means that some NodeB does not transmit power or its antenna is blocked.

l Cross-covering cell

If a cell cross covers, its signal exists in its second-circle neighbors.

Cross coverage may result from NodeB height or improper tilt. Cross-covering cell cause

interference to its neighbors and reduce network capacity. Cross coverage may be solved

by increasing the antenna tilt and height.

Do not create a coverage hole when solving cross-covering cell problem.

l An area without dominant cell

This area does not have a dominant cell or the dominant cell changes too frequently.

Handover occurs too frequently in an area without dominant cell. The network performance

is less efficient. The call drop rate increases.

Adjust the antenna tilt and azimuth to strengthen the coverage of one cell (the closer one)

and weaken the coverage of other cells (the distant ones) to solve this problem.

The procedure for coverage analysis is described as follows:

l Downlink coverage analysis is on the CPICH RSCP from the drive test.

The CPICH RSCP that is lower than the threshold value proves downlink coverage

problem.

Analyze the near-far relation of the coverage hole with its neighbor and the surrounding

environment of the coverage hole. Then check whether the CPICH RSCP distribution

of its neighboring NodeBs is normal.

Adjust the antenna tilt and azimuth to improve the coverage. Do not create new coverage

hole when solving the coverage hole problem. If the coverage hole problem cannot be

solved by antenna adjustment, add new NodeBs.

l Uplink coverage analysis is on the UE Tx Power from the drive test.

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The UE TX Power is higher than the threshold value proves uplink coverage problem.

For the area with both problems, solve the downlink coverage problem before solving

the uplink problem.

For the area with only uplink coverage problem, solve the problem by clearing uplink

interference, adjusting antenna tilt and azimuth, and adding TMAs.

Interference Analysis

Interference affects cell capacity and result in call drop and access failure. Interference analysis

consists of the downlink interference analysis and uplink interference analysis.

l Downlink interference analysis: if the CPICH Ec/Io is lower than the threshold value and

the RSCP meets the counter, the downlink interference exists. If the RSCP is poor too, it

is the coverage problem.

l Uplink interference analysis: High RTWP with low traffic volume proves uplink

interference.

Pilot Pollution Analysis

Pilot pollution means several strong pilots exist in one area without a dominant pilot frequency.

Pilot frequency results in decreased Ec/Io, frequent handover, call drop and relatively low

network capacity.

To analyze pilot pollution, perform the following steps:

1. Locate the area with poor Ec/Io value and high RSCP.

2. Check if pilot pollution exists in this area.

3. Locate the cells that cause the pilot pollution.

4. Analyze the RSCP and Ec/Io distribution by strengthening some strong pilots and

weakening some weak pilots. Determine the pilot to be strengthened and the pilot to be

weakened. Give the solution to the pilot pollution.

Handover Failure Analysis

Handover failure analysis consists of the following activities:

l Neighbor optimization: compare the neighbor information and drive test data through the

drive test analysis software. The software gives the advice of neighbor configuration for

every cell. Focus on the problem of missing neighbors. Missing neighbors causes call drop

during handover.

l Soft handover rate optimization: on basis of guaranteeing the coverage, the RF optimization

limits the soft handover rate to an acceptable range. To reduce the soft handover area, you

may increase the antenna tilt, adjust the antenna azimuth, lower antenna height, and weaken

the pilot frequency power.

4.4 RF Optimization Implementation

During the RF optimization implementation, you can modify the engineering parameters and

cell parameters to meet the KPIs.

Most coverage and interference problem can be solved by adjusting engineering parameters thatare described in the following. The priority level descends with the number.

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1. Downtilt

2. Azimuth

3. Antenna height

4. Antenna location

5. Antenna type

6. Adding TMAs

7. Changing NodeB type

For example, the NodeB supporting the 20 W TMA is changed into the NodeB supporting

the 40 W TMA.

8. Site location

9. Newly added NodeB or RRU

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5 Service OptimizationAbout This Chapter

During the service optimization, you can optimize the service and make the network counters

meet the acceptance requirements. The service optimization analyzes the drive test data and

performance data to solve service problems and improve the network counters to meet the

acceptance requirements.

According to the network status, the service optimization can be carried out at the following

stages:

l Before the network carries service

l

After the network carries serviceThe main difference of the two types is that if the number is allocated.

l For the network that does not carry service, the acceptance counters of the operator are

based on the data of the drive test along the KPI drive test course.

l For the network that carries service, the acceptance counters of the operator are the result

of the drive test along the KPI drive test course and the performance indicators.

During the service optimization, the counters to be met contain the following items:

l CS/PS call setup rate

l Call drop rate

l Soft handover rate

l Hard handover rate

l Call delay

l PS throughput

Figure 5-1 shows the flow chart for service optimization.

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Figure 5-1 Flow chart for service optimization

5.1 Service Optimization Data Collection

The service optimization data collection consists of drive test data collection, call tracing data

collection, performance data collection, and configuration data collection.

5.2 Service Optimization Data Analysis

During site verification, the equipment functional problems are solved. During the RF

optimization, the signal coverage problems are solved During service optimization, the problems

concerning the service and the unsolved problems of the earlier phases are analyzed and resolved.

The problem during this phase consists of coverage problem, access failure, handover failure,

and call drop.

5.3 Service Optimization Implementation


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5.1 Service Optimization Data Collection

The service optimization data collection consists of drive test data collection, call tracing data

collection, performance data collection, and configuration data collection.

Drive Test Data Collection

The drive test data is the data collected only at the UE side. During the service optimization, the

drive test data collection is more comprehensive than the RF optimization:

l More services under test: VP, Voice, and PS 384K

l More test methods: continuous call test, dialup test, and automatic test

Call Tracing Data CollectionThe following call tracing data at the NE side is collected:

l User signaling tracing data

l Cell signaling tracing data

l Standard interface signaling tracing data

l Call History Record (CHR) data

l Real-time performance monitoring data

Performance Data CollectionTo locate the radio performance problems at the cell level and network level, you should also

collect the performance data. The WRAN performance data falls into the following categories:

l Access

l Call drop

l Handover

l Traffic volume

l Congestion

Configuration Data Collection

The configuration data collection gathers configuration script file of the RNC. The configuration

data can help locating the problems.

5.2 Service Optimization Data Analysis

During site verification, the equipment functional problems are solved. During the RF

optimization, the signal coverage problems are solved During service optimization, the problems

concerning the service and the unsolved problems of the earlier phases are analyzed and resolved.

The problem during this phase consists of coverage problem, access failure, handover failure,and call drop.


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Coverage Analysis

Because the RF optimization is performed on clusters, there might be coverage problem that

exists in the overlapped areas of the clusters. Service optimization should also solve this problem

since the service optimization better the entire network. For the detailed analysis, refer to section

4.3 RF Optimization Data Analysis.

Access Failure Analysis

The access failure analysis checks if the drive test data and performance data meet the counters

described as follows:

l Access counters (drive test): the outgoing access ratio and incoming access ratio of the

Voice, VP, and PS services, the access delay of the Voice, VP, and PS services

l Access counters (performance data): paging ratio, RRC setup ratio, and the RAB setup

ratio.

The access failure makes the call drop rate of the drive test or the performance data do not meetthe acceptance requirements. The common types of access failure are listed as follows:

l Paging problem

l RRC setup problem

l RAB and RB setup problem

l Authentication and encryption problem

l Equipment fault

You may solve the access failure by modifying the following radio configuration parameters:

l Common channel power ratio: FACH/PCH/PICH/AICH transmit power

l Parameters of cell reselection: startup threshold of reselection, delay time of reselection,

delay of reselection, cell offset

l Parameters of random access: open loop power control constant, power step, and maximum

times of power adjustment

l Parameters of admission algorithm: admission switch and admission threshold

Handover Failure Analysis

Handover failure analysis contains the analysis on drive test data and the analysis on the

performance data. The analysis checks if the drive test data and performance data meet the

corresponding counters described as follows:

l Handover counter (drive test): soft handover rate, hard handover rate, inter-system

handover rate

l Handover counter (performance data): soft handover rate, hard handover rate, inter-system

handover rate

The handover failure makes the call drop rate of the drive test or the performance data do not

meet the acceptance requirements. The common handover failure consists of the following items:

l Neighbor configuration failure

l Hanover problem (handover delay and frequent handover)

l Equipment fault

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You may solve the handover failure by modifying the following radio configuration parameters:

l Parameters of soft handover: soft handover threshold, delay trigger time, delay, cell offset,

and filtering coefficient

l

Parameters of Inter-system handover: Inter-system handover threshold, delay trigger time,and so on

Call Drop Analysis

The call drop analysis contains the analysis on drive test data and the analysis on the performance

data. It checks if the drive test data and performance data meet the counters described as follows:

l Call drop counters (drive test): Voice service call drop rate, VP service call drop rate, and

PS service call drop rate

l Call drop counters (performance data): Voice service call drop rate, VP service call drop

rate, and PS service call drop rate

The call drop makes the call drop rate of the drive test or the performance data do not meet the

acceptance requirements. The common problems that cause call drop consists of the following

items:

l Neighbor configuration failure

l Coverage hole

l Strong interference

l Handover failure (handover delay and frequent handover)

l Equipment fault

You may solve the call drop by modifying the following radio configuration parameters:

l Dedicated channel power: maximum downlink transmit power of the radio link, maximum

uplink transmit power of the UE

l Parameters of soft handover: soft handover threshold, delay trigger time, delay, cell offset,

and filtering coefficient

l Parameters of Inter-system handover: Inter-system handover threshold, delay trigger time,

and so on

l The timer and counter related to the call drop

5.3 Service Optimization Implementation

During the service optimization implementation, you can modify the radio configuration

parameters to enhance the performance. When modifying the network planning data, follow the

parameter modifying principles of our company to avoid major accident.

Perform the following preparations:

l Make a detailed data modification plan, which contains the following contents:

Objective

The version of the network equipment and the related instructions

Modification procedures


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The modification details, which include the value change of the parameters after the

modification

The commands

Operation time: is determined by the network security and the operation impact on

services. Modify substantial data and high-security data at midnight, when the trafficvolume is low. If a small quantity of data are modifies and the network security level

is low, dynamically modify the data when the local traffic is not busy.

Measures for faults

l Pre-review the substantial data modification and high-security data modification.

l Submit the application for network operation to the customer before the data modification.

The application should at least includes the following items:

The content of the modification or operation

The purpose of the modification or operation, or the problem to be solved

The time of the operation The resources asked from the customers: personnel, vehicles, and SIM card

Measures for faults

Operation impact on services, which includes the performance data counter

l Back up the original data and record the date in every operation.

Check the following after the modification:

l Back up the latest data file on the BAM and record the date.

l Check if the NodeB and cells work properly after the modification. Conduct the dialup test

to ensure the normal service supply.

l Check the performance data which includes access rate, congestion rate, call drop rate and

handover rate to decide if faults occur. If any fault occurs, determine the solving measures

to ensure the proper running of the equipment.

l Record the data modification and impact so that the engineers can take the modification as

reference during later phases.

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6 Network AcceptanceAbout This Chapter

Based on the performance data and drive test, the network acceptance checks if the optimized

network meets the optimization counters, evaluate the optimized network quality, and display

the network optimization.

The networkoptimization acceptance is triggered when the network performance meets the

requirements.

l The drive test acceptance is triggered when all the counters in the tested area meet the

requirements.

l The traffic statistic acceptance is triggered when all the counters meet the requirements andthe situation is stable for seven days.

6.1 Network Acceptance Counters

Acceptance counters are of drive test data and performance data.

6.2 Contents of Network Acceptance Report

After you finish the network acceptance test, you need to output the network acceptance report

on XXX project and the network optimization report on XXX project.

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6.1 Network Acceptance Counters

Acceptance counters are of drive test data and performance data.

6.1.1 Drive Test Counters

Drive test counters are obtained by drive test along the predefined test course.

6.1.2 Performance Counters

Performance counters are obtained from the traffic measurement.

6.1.1 Drive Test Counters

Drive test counters are obtained by drive test along the predefined test course.

Table 6-1 3G network KPI of the drive test and cell quality test

Counter Description

Call setup rate

of the 12.2K

Voice service

Outgoing access ratio = (the number of calling setups)/(the number of

calling requests) x 100%

Incoming access ratio = (the number of called setups)/(the number of called

requests) x 100%

Call setup rate

of the 64K CS

service

Outgoing access ratio = (the number of calling setups)/(the number of

calling requests) x 100%

Incoming access ratio = (the number of called setups)/(the number of called

requests) x 100%

PDP context

activation ratio

= (the number of activations)/(the number of activation requests) x 100%

Call drop rate of

the 12.2K Voice

service

= (the number of call drops)/(total number of setups) x 100%

Call drop rate of

the 64K CS

service

= (the number of call drops)/(total number of setups) x 100%

Call drop rate ofthe 128K PS

service

= (the number of call drops)/(the number of the PDP context activations)x 100%

Soft handover

rate of the 64K

CS service

l According to the information recorded by drive test tool, the number of

active set update requests received by the VP service UE is A1, the

number of active set update completions sent by the UE is B1.

l Soft handover rate = B1/A1

Connection

delay of the

12.2K Voice

service

The interval from UE sending the RRC connect request to UE receiving

the Alerting message. Record the average value.


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Counter Description

Connection

delay of the 64K

CS service

When the calling party presses the call button, the time is recorded as T0.

When the calling party hears the first ringing, the time is recorded as T1.

The called party answers as soon as he hears the ringing. When the calling

party sees the figure, the time is recorded as T2.

The interval from T0 to T1 is ringing time. The interval from T1 to T2 is

figure time.

The interval from that the calling UE sends ringing message to that the

called UE answers automatically and sends the connect message is T,

which should be obtained beforehand.

Connection delay = T2 - T0 - T

The rate and

delay of inter-

system

handover in CS

domain

(WCDMA to

GSM)

The calculation of inter-system handover rate is described as follows:

l According to the single UE tracing message from the RNC, the number

of RELOCATION REQUIRED messages sent by the RNC to the CNis recorded as A, and the number of IU RELEASE COMMAND

messages received by the RNC is recorded as B. The value of the reason

in the IU RELEASE COMMAND message must be Successful

Relocation.

l Inter-system handover rate for a single UE in CS domain (WCDMA to

GSM)= B/A

l Total Inter-system handover rate in CS domain (WCDMA to GSM)=

B/A

The calculation of inter-system delay is described as follows:

l Record every delay from that the RNC sends HANDOVER FROM

UTRAN COMMAND message to that the RNC receives the IURELEASE COMMAND message.

l Average all the delay value. The result value is the Inter-system

handover delay.

The rate of inter-

system

handover in PS

domain

(WCDMA to

GPRS)

l According to the single UE tracing message from the RNC, the number

of the CELL CHANGE ORDER FROM UTRAN messages sent by the

RNC to the UE is recorded as A, and the number of the IU RELEASE

COMMAND messages received by the RNC is recorded as B. The value

of the reason in the IU RELEASE COMMAND message must be

Normal Release.

l

The rate of inter-system handover for a single UE in PS domain(WCDMA to GPRS)= B/A

l The total rate of Inter-system handover in PS domain (WCDMA to

GPRS)=B/A

The time of Data

transmission

break during

Inter-system

handover in PS

domain

(WCDMA to

GPRS)

l Record interval from the failure to the recovery of every Ping.

l Average all the recorded value.

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Type Name Definition

Intra-frequency

hard handover rate

=(The number of the physical link reconfiguration

messages received by the RNC)/(the number of the physical

link reconfiguration messages sent by the RNC)

The physical link reconfiguration is for intra-frequency

hard handover.

Inter-frequency

hard handover rate

=(The number of the physical link reconfiguration

messages received by the RNC)/(the number of the physical

link reconfiguration messages sent by the RNC)

The physical link reconfiguration is for inter-frequency

hard handover.

The rate of inter-

system handover in

CS domain (3G to2G)

=(The number of the successful inter-system handovers in

CS domain)/(the number of the inter-system handovers

attempt in CS domain)l The number of the inter-system handover attempts in CS

domain is the number the RELOCATION REQUIRED

messages sent by the RNC to the CN.

l The number of the successful inter-system handovers in

CS domain is the number of the IU RELEASE

COMMAND messages received by the RNC. The value

of the reason in the IU RELEASE COMMAND message

must be Successful Relocation.

The rate of inter-

system handover in

PS domain (3G to2G)

=(The number of the successful inter-system handovers in

PS domain)/(the number of the inter-system handover

attempts in PS domain)

l The number of the inter-system handover attempts in PS

domain is the number of the CELL CHANGE ORDER

FROM UTRAN messages sent by the RNC to the UE.

l The number of the successful inter-system handovers in

PS domain is the number of the IU RELEASE

COMMAND messages received by the RNC. The value

of the reason in the IU RELEASE COMMAND message

must be Normal Release.

6.2 Contents of Network Acceptance Report

After you finish the network acceptance test, you need to output the network acceptance report

on XXX project and the network optimization report on XXX project.

Network Acceptance Report

The network acceptance report on XXX projectcomprises the following items:

l Background

l Networking mode

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l Acceptance area dividing, KPI test route

l Acceptance counters (drive test and performance data)

l Acceptance method (drive test and performance data)

l

Acceptance result

Network Optimization Report

The network optimization report on XXX projectcomprises the following items:

l Background

l Networking mode

l Optimization process, content, and progress

l Optimization objective (drive test and performance data counters)

l Optimization conclusions

l Single site verification contains the following items:

Testing method

Single site verification analysis: table of problems, table of measures, and table of

unsolved problems

l RF optimization contains the following items:

Testing method

Coverage optimization result:

Cell dominance analysis (CPICH SC)

Downlink coverage analysis (CPICH RSCP, CPICH Ec/Io)

Uplink coverage analysis (UE Tx Power)

Downlink interference analysis

Uplink interference analysis

Pilot pollution optimization result

Handover optimization result

RF optimization analysis: table of known problems, table of measures, and table of

unsolved problems

l Service optimization contains the following items:

Testing method Service optimization result (drive test):

Analysis on the call setup rate and call drop rate of CS service

Analysis on the call setup rate, call drop rate, and throughput of PS service

Analysis on the inter-system handover rate

Service optimization result (performance data):

Analysis on the accessibility

Analysis on the call drop

Analysis on the mobility

Service optimization analysis:


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7Network Optimization ToolsAbout This Chapter

Network optimization tools are used for data collection, data analysis and can simplify the

network optimization and improve the working efficiency. The tools that you use during network

optimization are: Probe, Assistant, and Nastar.

7.1 Probe

As an air interface test tool for data collection and radio network planning and optimization

verification, the Probe supports the WCDMA, HSDPA, GSM or GPRS network systems

7.2 Assistant

As a professional parsing tool for analyzing the radio network background, the Assistant supports

the test data of the WCDMA, HSDPA, GSM, GPRS network system and the RNC data. It also

supports the formats of the drive test data provided by the main manufacturers. The Assistant

provides: combined analysis on uplink and downlink data, intelligent expert system, event

simulation, displaying, statistics, filtering, and reporting.

7.3 Nastar

The Nastar perform the comprehensive analysis on the performance data, CHR, call tracing, and

data configuration on an integrated platform, and support the functions of querying by theme,

intelligent expert system, weekly reporting, monthly reporting, reporting on health check, and

configuration check. The Nastar can help the operator to locate and solve network problems and

promote the working efficiency of the site engineers.

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7.1 Probe

As an air interface test tool for data collection and radio network planning and optimization

verification, the Probe supports the WCDMA, HSDPA, GSM or GPRS network systems

The uses of the Probe are described as follows:

l Test network quality and radio parameters.

l Decode the message of the Uu interface and display the information of data, cell, and

geographical location in real-time.

l Monitor, trace, and test the status of the system in real-time.

The main functions of the Probe are listed as follows:

l Supporting multi-mode test in WCDMA/HSDPA/GSM/GPRS

l Supporting CS and PS measurement

l Supporting multi-UE test

l Supporting Scanner test

l Supporting indoor measurement

l Presetting test plan

l Supporting judgment of predefined events

l Supporting hardware alarm

l Filtering test parameter

l Automatically saving, exporting, and play backing, log file

l Displaying co-activated information

l Geographically displaying wireless measurement parameter in real-time

l Supporting dynamic and static adjustment to GPS information

l Displaying and parsing the messages of the Uu interface

l Displaying RLC and APP throughput

l Displaying custom parameters

l Supporting GPS time synchronization

7.2 Assistant

As a professional parsing tool for analyzing the radio network background, the Assistant supports

the test data of the WCDMA, HSDPA, GSM, GPRS network system and the RNC data. It also

supports the formats of the drive test data provided by the main manufacturers. The Assistant

provides: combined analysis on uplink and downlink data, intelligent expert system, event

simulation, displaying, statistics, filtering, and reporting.

The uses of the Assistant are described as follows:

l Have a panorama view of network performance.

l Locate the network troubles.


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l Improve the network quality.

l Verify the network planning and optimization.

Table 7-1 lists the functions of the Assistant.

Table 7-1 Functions of the Assistant

Function Description

Analyzing the test

data in WCDMA -

GSM dual mode

The Assistant analyzes the test data in the WCDMA and GSM

networks. It also supports the display of engineering parameters and

real-time data.

Importing multiple

test device data

The Assistant imports test data from:

l GENEX Probe

l Huawei RNC

l DTI Scanner

l Anritsu Scanner

l Agilent E6474A

l Agilent E7476A

The Assistant offers Excellent display and analysis of the test

counters.

Flexibly adding the

type of the drive test

data

With the Assistant, update one file to add a device type.

Four geographic

binning modes and

three data sampling

methods

The four geographic binning modes are:

l Distance binning

l Grid binning

l Time binning

l No binning

The three data sampling methods are:

l Average value

l Maximum value

l

Minimum value

Independent analysis

on the drive test

device

Independent display and analysis of the devices and the frequencies

Environment of

scrambling code

multiplexing

The Assistant analyzes the environments for scrambling codes

multiplexing in a large-scale network.

Automatically

combining the drive

test devices

The Assistant automatically combines the drive test devices.

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Analyzing the

measurement data of

uplink and downlink

in an integrated

manner

By synchronizing the GPS time, the Assistant can display the drive

test data and the RNC data simultaneously. This enables integrated

analysis of uplink and downlink data that includes RNC subscriber

tracing signaling.

Analyzing by the

geographical area or

time span

After the Assistant locks the geographical area or the time span, the

specified data becomes the basis for later analysis.

Displaying the drive

test track

The Assistant automatically displays drive test track and adjusts the

display parameters.

Test data playback The Assistant supports:

l Test data playback both automatically and manually

l Display of the measurement parameters of problems in detail

l Quick troubleshooting

Multiple data display

modes

The data display modes which integrate the common operation

methods consist of the following :

l Map

l Curve chart

l Customized XY chart

l PDF chart

l ExcelFor map mode, the Assistant provides:

l Fast pilot relation line

l Layer offset

l Overlapped path filtering

l Area memory

l Display and control of engineering parameters

For curve chart mode, the Assistant supports:

l Dynamic modification and dragging of data curves

l Graph zooming

l Graph rotating

l Chart customization

For Excel mode, the Assistant supports:

l Searching

l Copying

l Calculation


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Bidirectional multi-

window co-

activation

The Assistant supports the data co-activation among maps, charts,

Excels, and signaling events.

Displaying the real-

time attribute data

The Assistant offers the real-time display of:

l Scanner coverage

l UE pilot information

Parsing Layer 3

signaling

The Assistant supports the Layer 3 signaling parsing. The signaling

parsing contains:

l RRC

l NAS

l RR

The Assistant searches a text by:

l Message name

l Message body

Various application

analysis items

For the Scanner data, the Assistant supports the following item:

l Handover event simulation

l Pilot pollution analysis

l Soft handover statistics

l Neighbor analysis

l Detailed analysis report

For the UE data, the Assistant provides the analysis reports on:

l UE network event predefinition

l PS service statistics

l CS service statistics

Exporting data in

different display

formats

The Assistant supports the data export in different display formats,

such as:

l .bmp format

l .txt format

l .xls format

Filtering the data by

indicator

The assistant filter the imported data by indicator.

Word collector With the word collector, the Assistant exports the browsed pictures

and Excels to a Word file, thus saving many copying and posting.

Simulating the

Scanner single site

closure

The Assistant simulates the changes of the pilot signal brought by the

site closure to determine the impact of the site on the pilot frequency.

The focus should be on the recalculation of the RSSI on the drive test

point covered by the site.

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Automatically

matching RNC

messages

The Assistant supports the automatic matching between the RNC

messages and UE messages when importing the RNC data.

Analyzing the

HSDPA statistics

The data reflects the following items:

l Current network performance

l Parameter configuration

l Rate statistics

l Channel decoding statistics

l Service performance

Summarizing the

KPIs by sites

The Assistant sums up the KPIs by site. These KPIs are:

l Soft handover

l Call setup

l Call drop

l Call setup failure

Intelligent report

system

The Assistant automatically generates a drive test report.

7.3 NastarThe Nastar perform the comprehensive analysis on the performance data, CHR, call tracing, and

data configuration on an integrated platform, and support the functions of querying by theme,

intelligent expert system, weekly reporting, monthly reporting, reporting on health check, and

configuration check. The Nastar can help the operator to locate and solve network problems and

promote the working efficiency of the site engineers.

The uses of the Nastar are described as follows:

l Analyze and locate the network problems.

l Monitor the performance of the entire network

Table 7-2 describes the functions of the Nastar.


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Optimization

solutions for intra-

frequency

neighbor

On basis of the analysis on the performance data, CHR, and engineering

parameters, the Nastar locates the problems of neighbor configuration

and gives the solutions to optimize the neighbors and ensures the network

mobility.

You may perform the following operations to optimize the neighbors

with the Nastar:

l Querying the original record of the cell configuration

l Intelligent analyzing on neighbor optimization

l Querying the handover record

l Querying the Top N neighbor configuration

l Generating the report on neighbor optimization

Solutions for pilot

pollution

On basis of the analysis on the engineering configuration parameters,

CHR, and engineering parameters, the Nastar analyzes the pilot

pollution.

The user can view the analyzing result on the map and research the

analyzing report.

For analyzing the pilot pollution, the Nastar provides the following

functions:

l Statistics on the areas with pilot pollution

l Geographically analyzing the pilot pollution

l Generating the report on pilot pollution analysis

Solutions forcoverage analysis

On basis of the analysis on the configuration data and IOS data, theNastar analyzes the coverage.

l Downlink common pilot channel coverage analysis

l Link quality analysis

l Cross coverage analysis

l Report on coverage analysis

Solutions for

interference

analysis

On basis of the analysis on the configuration data, RTWP data, and

engineering parameters, the Nastar analyzes the interference.

Configurationcheck

On basis of the analysis on the performance, configuration data, andengineering parameters, the Nastar checks and compares the following

configuration data to ensure the correctness and reasonability of the data:

l Querying the configuration data geographically

l Comparing the MML commands of different versions


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