WPO-13 WCDMA Radio Network Optimization-86

8/9/2019 WPO-13 WCDMA Radio Network Optimization-86

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WCDMA Radio Network Optimization

ZTE University



Content

Overview of WCDMA radio network

optimizationGeneral flow of WCDMA radio network

optimization

Engineering Optimization Method

Operation and maintenance Optimization



Q

Coverage

Quality of

service

Operator

revenue

Operation

cost

Network

capacity

¥

A top-notch network is demanded by customers, started from planning,

improved during the process and gets its heyday via optimization

A topA top--notch network is demanded by customers, started from planning,notch network is demanded by customers, started from planning,

improved during the process and gets its heyday via optimizationimproved during the process and gets its heyday via optimization

Service Concept of Network Planning and

Optimization



Cause of Network Optimization

Network optimization must be carried on when the

following events occur:

Network construction completed Network capacity expanded

Obvious quality reduction of network or increase of

user complaints caused by some poor KPI(s) which

cannot meet the requirements

Radio environment changed

Traffic distribution changed

Other instant events having great influence on quality

of network



Target of Network Optimization

From the angle of network quality

Improve the quality of network service

Improve the utilization rate of equipments andresource

Expand network capacity

From the angle of operator Improve user satisfaction

Reduce cost

Create competition advantages



Main Problems of WCDMA Network Optimization

Various problems may occur during network running.

The main problems are:

Call drop problem Access problem

Pilot pollution problem

Disturbance problem Coverage problem

Switch problem

Data service transmission problem Paging and Registering problem

Load and admission control problem

Quality of service problem



After network planning and design, during network construction and launch, it

accesses to the network optimization stage

Depending on the time segment, work objectives and work content of its

implementation, optimization can be divided into Engineering Optimization andoperation/maintenance optimization

Process of Network Optimization



Classification of Network Optimization

Engineering optimization

Engineering optimization refers to the network

optimization conducted after the completion of networkconstruction and before the number allocation. Its major

purpose is to enable the network to work normally and

ensure that the network can fulfill the planned coverage

and interference objectives.

The major work contents of Engineering Optimization

include:

Checking whether the cell configuration is consistent withthe planned objective of the network

Eliminating the hardware fault of the system

Making the coverage and interference reach a satisfactory

level



Classification of Network Optimization

Operation and maintenance optimization

Operation and Maintenance (O&M) optimization

indicates to improve the network quality and

customer’s degree of satisfaction through optimization

during the operation of the network.

It includes three parts of contents:

Routine maintenance

Stage optimization

Network operation analysis



Difference between Engineering optimization and

Operation/Maintenance optimization

Engineering optimization Operation and maintenance optimization

Stage Before commercial number

allocation

After commercail number allocation

Network load Almost idling User capacity increases

Target of

optimization

Let the network meet the

planned coverage and quality

requirements

To ensure the network to work normally and

improve the network KPIs. To find the

network potential problem. To finish

analyzing network changing in advance.

Key

optimization

Improve radio coverage Improve network KPIs

Optimization

method

Focus on DT and CQT of the

whole network

Focus on monitoring and analyzing KPI on

NM, and then pertinence DT and CQT.



Optimize the Architecture of Project Organization

In order to accomplish the project in time, the project can be launched by taking optimization

team as the smallest implementation unit and deployed network planning and optimization

human resources according to network size and project schedule. At the same time, the

whole project can be controlled in aspects of management, technique and quality to

guarantee the efficiency and quality of network planning design and optimization.

Area optimization

manager 1

WCDMA network

optimization manager

…

Optimization

engineer

Drive testengineer

Tower worker

WCDMA RNPO

equipment engineer

R & D key

supportingteam

Network

optimization tool

supporting team

Optimization

engineer

Drive testengineer

Tower worker

Area optimization

manager n

Optimization

engineer

Drive testengineer

Tower worker

Optimization

engineer

Drive testengineer

Tower worker

WCDMA RNPO

expert team

Optimization team



Optimization project human resources deployment

module-Engineering optimization period

Classification Type 1 Type 2 Type 3 Type 4 Type 5

Base station size 200 500 800 1500 3000

Network planning andoptimization manager

1 1 1 1 1

Optimization engineer 2 5 7 13 25

Full

configuration

4 10 14 26 50

Simplify

configuration 2 5 7 13 25

Full


Simplifyconfiguration

1 2 3 5 9

Tower

worker

Drive testengineer

Full configuration: There are two drive engineer and one tower worker in one optimization

team

Simplify configuration: There are one drive engineer in one optimization team. And threeoptimization teams share one tower worker



Optimization project human resources deployment

module-Operation and Maintenance optimization period

Classification Type 1 Type 2 Type 3 Type 4 Type 5

Base station size 200 500 800 1500 3000

Network planning andoptimization manager 1 1 1 1 1

Optimization engineer 1 2 3 5 8Full


Simplify


Full


Simplifyconfiguration

1 1 1 3 5

Tower

worker

Drive test

engineer

Full configuration: There are two drive engineer and one tower worker in one

optimization team

Simplify configuration: There are one drive engineer in one optimization team andone tower worker in the area covered by one RNC



Configuration of Tools

NameNumber for Each

Group

Useage Remarks

Handheld GPS 1 Record the address of the station location

Compass 1 Record the location of the antenna

Laser Rangefider 1 Record the height of the base station

Digital Camera1

Record the environment situation aroundthe base station

Drive Test Software (CNT) 1 Collect the drive test data

Drive Test Analyze

Software(CNA) 1

Analyze the drive test data

Scanner 1

Used with drive test tool for frequency

cleaning and pilot frequency scanning

One set for

multi groups

Network Optimization

Subsystem（CNO）1

Verify the radio parameters, optimize the

adjacent region and monitor/analyze the

performance

One set for one

city

Interference Analyzer 1

Analyze and locate the interference One set for

multi groups

Test Mobile Phone 2～4 Test CS service

Test Data Card 1 Test PS service

Car 1

Car for drive test Including thedriver



Content


optimizationGeneral flow of WCDMA radio network

optimization





Network Optimization Flow

Artificial/planreport

Start

Preparation work

Spectrumscanning

Calibration test

Network data

collectionData analysis

Parameter check

Problem Locating

Making optimization

plan

Carrying out optimizationplan

Optimizationverification

Networkperformance

meets the

requirements?

Optimization project acceptance

Documentation archive

Optimizationproject plan

Networkevaluation report

Optimizingadjustment plan

Optimizingadjustment record

Network optimizationreport

End



Network Optimization Flow

Radio network optimization flow includes the following steps:

Preparation work

Spectrum scanning (Optional)

Calibration test (Optional)

Network data collection

Data analysis

Parameter check (Optional) Problem locating

Making optimization plan

Carrying out optimization plan Optimization verification

Optimization project acceptance

Documentation archive



Network Optimization Flow - Preparation Work

Analyzing the Requirements

Understand the coverage and capacity requirements.

Confirm the setting of the optimization testparameters.

Confirm the work division interface with the customer.

Confirm the acceptance standard of each item.

Drawing the work plan

Collecting and investigating materials

Obtain all the reports at the network planning stage. Obtain the site information, antenna feeder

information and the setting of the system parameters

in the current network.

Make clear the problems in the current network.




Preparing optimization tool

DT tools are the basic tools for network optimization

test. They include DT software, test mobile phone,

receiver and GPS. Besides, some DT equipment

requires a dual-serial-port card.

Possible signaling analyzer need be used for

signaling tracing and locating. If interference test needbe conduct, device such as spectrograph may be

required; If the engineering parameters need be

adjusted, then devices such as compass may be

used. 。




People & Organization

Chief person of project

Network analyze engineer Optimization engineer

Testing engineer

OMC switch engineer Base station (Troubleshooting) engineer

Staff personnel: pilot, car driver and document

manager



Network Optimization Flow - Spectrum Scanning

(Optional)

Spectrum scanning

With the authorization from the customer, scan and

confirm the frequencies used by the network at

present in the optimization area to ensure that the

frequencies are clean and available.



Network Optimization Flow - Calibration Test

(Optional)

Calibration test

Calibration test of vehicle-mounted antenna

Calibration test of the external antenna of the testmobile phone

Test of the average penetration loss of the vehicle

body

Test of building loss



Network Optimization Flow - Network data collection

Source of network optimization data:

DT data

CQT data OMC performance statistic data

User complaint information

Alarm information Other data



Drive Test (DT) refers to the process to move along a

selected path in the coverage area and then record

various test data and location information through DT

equipment.

DTDT




CQTCQT


CQT refers to the fixed-point test conducted at importantplaces in the coverage area.

Scenic spot, airport, railway station, bus station and port

Important hotels (star-level hotels)

Catering and entertainment sites, large shopping malls

Important residential communities and office areas

Other important areas

CQT can use professional testing software. ZXPOS CNT1 (UMTS Edition) can complete the CQT

automatically.



OMC performance statistic data reflect the operation quality of the

whole network from the point of view of statistics. They can be usedas the most important basis for assessing the network performance.

OMC Performance Statistic Data

The main network KPIs include:

Access success rate

Call success rate

Dropped call rate

Soft-switching success rate

Hard-switching success rate

OMC Performance Statistic Data




As the end user of the network service, ordinary user has

more direct experience of the network performance.

The user complaint information most directly reflects the

disadvantage of the network. Users are most concerned with the problems included in the

complaints, which need be solved as soon as possible.

The complaint includes geographical location information.

Generally the problems complained include poor signal coveragequality, difficulty for call completion and frequent call drop.

User Complaint InformationUser Complaint Information




Alarm information includes the alarm information of the

RNC, Node B and CN background NMS.

It reflects the abnormal or near-abnormal status in

equipment use or network operation. During networkoptimization, the alarm information deserves close

attention and need be viewed periodically, so that

warning information or problems can be found in time to

avoid the occurrence of accident.

Alarm InformationAlarm Information




In addition to the data listed above, there are data

obtained through the signaling analysis system, network

flow test system and voice quality assessment system.

Other DataOther Data




Network Optimization Flow - Data Analysis

Data analysis indicates to make clear the network

operation quality, assess the network performance,

find and locate the possible network problems and

provide suggestions for network optimization byanalyzing the DT data, CQT data, OMC

performance statistic data, user complaint

information and alarm information. DT data analysis

CQT data analysis

OMC performance statistic data analysis User complaint information analysis

Alarm information analysis

Other data analysis



The DT data collected by scanner or test mobile

phone can be analyzed according to

professional network optimization and analysis

software.

ZXPOS CNA1 (UMTS Edition) is a special analysis

software for WCDMA radio network optimization.

Based on the DT data and other auxiliary data, it can

conduct several kinds of intelligent analysis for theradio network to locate the network problems quickly

and accurately and implement network optimization.

DT Data AnalysisDT Data Analysis




CQT Data AnalysisCQT Data Analysis

The following KPIs can be obtained by

analyzing CQT data:

Call success rate

Dropped call rate

Call delay

Call quality

Data service average rate, ect.




OMC performance statistic data analysis can

generate the General Performance Index (GPI)

and Key Performance Index (KPI) of the radio

network. They are important data for assessing

the network performance.

Through the analysis of OMC performance

statistic data, the area where the problem has

occurred can be directly located on thebackground. This helps accurately locate the

problem.

OMC Performance Statistic Data AnalysisOMC Performance Statistic Data Analysis


N t k O ti i ti Fl D t A l i



Indices that reflect the resources utilization include: ratio

of worse cells, ratio of over busy cells, ratio of over idlecells and utility of cell code resources.

Indices extracted from the OMC background also include

other indices that reflect network operation quality:

access success rate, call completion rate, call drop rate

and call delay.

Indices that reflect system handover performance

(handover success rate) include: softer handoversuccess rate, soft handover success rate, cross-lur

interface software handover success rate, hard handover

success rate and inter-system handover success rate.

OMC Performance Statistic Data AnalysisOMC Performance Statistic Data Analysis





The user complaint can directly reflect the problem phenomena

and geographical information. From the complaint the followinginformation can be collated out:

Area of poor signal coverage

Area of low call success rate

Area of high call drop rate Area of poor conversation quality, etc.

User Complaint Information AnalysisUser Complaint Information Analysis

As the end user of the network service, ordinary users can feel

the network performance most directly. Due to the diversity

and individuality of each problem described by the user, theuser complaint data involve not only the base station side, but

also the billing system and transmission system. Therefore, the

complain data need be carefully identified to find the data that

can actually reflect the network status.





Alarm Information AnalysisAlarm Information Analysis

Alarm information includes a large amount of abnormal

warning information during network operation. It can help

the optimization engineer to quickly locate the problem

and find the direction and method for solving the problem.

Besides, OMC performance statistic indices may also be

abnormal. When the relation between the OMC

performance statistic indices and the relevant alarm

information is found, it will greatly help locate the networkfault and solve the problems.





Other Data AnalysisOther Data Analysis

Other data include the data obtained through thesignaling analysis system, network flow test system and

voice quality assessment system.

By tracing the signaling of such network interfaces of the

network as Uu, Iub and Iur interfaces, we conduct

statistics of the signal traffic and message of each

interface, find the abnormal signaling flow; with reference

to other statistic data, we can locate the fault more

accurately and can find various problems that are

generaly difficult to find and eliminate potential faults.


Network Assement before Optimization



Network Assement before Optimization

According to network assement before optimization,

the actual operating conditions of the network can

be obtained. It facilitate the comparison of the

performance before and after the networkoptimization.

The assessment is used to discover the problems in

the network, provide guide for the networkoptimization at the next stage.

By analyzing DT data, CQT data, OMC performance

statistic data, user complaint information, alarminformation and so on, we can know the quality of

the network and assess the performance of the

network.

Network Optimization Flow - Parameter



p

Check (Optional)

Data analysis can help find bad indices in the

network. If it is found that the parameter

configuration is unreasonable and influences the

network performance, the parameter configurationof the abnormal base station must be checked. The

contents of the check include:

Check the base station. Check whether the radio configuration parameter of

the cell is consistent with the planned value.

Check the relevant configuration parameters of thevoice service and data service.

Network Optimization Flow Problem



p

Locating

The problems of radio network are found in the

following major aspects:

Equipment software and hardware problems

Engineering parameter problem

Radio parameter problem

Network capacity problem

Network Optimization Flow Making Optimization



Plan

The major adjustment policies for network

optimization includes:

Adjust the software and hardware of the equipment.

If software problem is found through parameter check,

the software version shall be confirmed and updated in

time. Hardware problem is generally board fault, in

which case the faulty board need be replaced by a

normal one.

Adjust the network engineering parameters.

This includes the adjustment of the direction angle,

downward tilt angle, height and location of the antenna. After the network construction is completed, coverage

and interference problems in the pre-launch network

optimization shall be solved by adjusting the network

engineering parameter.

Network Optimization Flow Making Optimization



Plan

The major adjustment policies for network

optimization includes:

Adjust the network radio parameters.

This includes the adjustment of the access parameter,

paging parameter, power control parameter, handover

parameter and search parameter, etc.

Adjust the neighboring cell list of the system. Optimize the neighboring cell list of the network through

DT data analysis.

Capacity analysis or busy analysis.

Possible measures include cell splitting, adding cells

and micro cells, RF extension and use of multiple

carriers.

Network Optimization Flow Carrying Out



Optimization Plan

If the network scale is large, the network need be divided into differentbase stations clusters to locate and solve the network problems indifferent areas.

After the all base station clusters have been optimized, the global

network can be optimized to solve global network problems andproblems across different clusters. Then assess the performance ofthe global network after the optimization and verify whether thenetwork performance indices have meet the acceptance standard andreached optimization objectives.

The cluster division principles shall be adjusted according to theactual situation, generally according to the topography of the localarea. neighboring areas that have special requirements for data orvoice service shall be grouped in the same cluster to facilitateoptimization debugging. Besides, cluster division can also beconducted according to the problems found in the networkassessment before the optimization. There shall be overlap betweentwo neighboring clusters.

The optimization of different clusters can be implemented either

parallel or serially depending on the resources and time requirement.

Network Optimization Flow Optimization



verification

After the network optimization solution is implemented, it is

necessary to verify whether the network problems have been

solved or whether the network performance is improved.

To implement the optimization verification, also first collectthe network operation data and analyze the collected data.

After the optimization solution is implemented, assess the

network performance again by analyzing the DT data, CQT

data, OMC performance statistic data, user complaintinformation and alarm information.

Compare the network performance indices before and after

the optimization and verify whether the network problems

are solved or the network performance has met therequirement after the optimization.

Network Optimization Flow Optimization



Project Acceptance

Acceptance test shall be conducted for the required

network performance indices according to the

contract requirements. Contents of the test such as

the test path, test point and call mode shall be setaccording to the principle determined at the contract

or requirement analysis stage. In principle the

customer shall participate in the acceptance test.

Network Optimization Flow Documentation



archive

After the optimization verification and project

acceptance, the network optimization report need be

submitted and relevant documentations need be

archived.

The network optimization report includes such

contents as problem analysis, locating process,

optimization measures adopted, comparison of theindices before and after the optimization, remaining

problems of the network and suggestions for

subsequent construction.

Content



Content


optimization

General flow of WCDMA radio network

optimization



Engineering Optimization




At different stages of UMTS network construction,

the objectives of network optimization are also

different.

The objectives of (Pre-launch) Engineering

Optimization include:

Enabling the network to work normally

Issues deserving attention: coverage, function and

interference





After the network planning and construction is

completed and before the pre-launch, the major

work contents of Engineering Optimization include:

Eliminating the hardware fault of the system

Checking whether the cell configuration is consistent

with the planned objective of the network

Making the coverage and interference reach asatisfactory level




g g p

Eliminate the hardware fault of the system:

It is very important to eliminate any hardware fault

from the system.

Generally hardware faults are eliminated according to

the division of base station cluster.

The elimination of hardware faults is the responsibility

of the equipment supplier. However, it is also very important for the carrier to

understand the process of hardware fault elimination

and obtain the ability for checking the equipment.




g g p

Check the cell configuration:

Whether the site is in the correct position

Whether the type of the antenna is correct

Whether the installation height, direction angle and

downward tilt angle are all deployed according to the

planned solution

Whether the type of the feeder is correct and whetherits length is appropriate

Whether parameters (such as common channel

power) of the cell are consistent with the plannedparameters.




g g p

Objectives for coverage and interference

optimization

Typical threshold:

The intensity of the pilot received in 95% of the

coverage area is greater than -89dBm (in dense urban

areas) or -94dBm (in general urban area).

The pilot Ec/Io measured in 95% of the coverage areais greater than -10dB.



Steps for improving the interference:

Determine the areas where the pilot Ec/Io is lower

than the threshold.

Check the pilot level in these areas (which may havemore than 3 pilots).

From the pilots received in these areas, find the pilots

unexpected (these pilots come from the cells that arenot designed to provide coverage for these areas).

Reduce the intensity of these “unexpected” pilots

(generally by increasing the downward tilt). Pay

attention to the influence resulting therefrom on the

coverage within the service range of the cell (the

influence can be checked with the planning tool).



Engineering Optimization Flow



Single station optimization

testing Site improvment

Single station check and

acceptance

Cluster optimization testing

Cluster optimization dataanalysis and optimization plan

extablished

Carrying out cluster

optimization plan

Cluater optimization

acceptance

Cluster boundary

optimization

Block optimization

Whole network

optimization and verification

Whole Network

Optimization

Base Station

Cluster Optimization

SingleStation

Verification

Single Station Verification Flow



Preparations before Single Station Verification Testing



OMC Engineer Optimization Engineer

Ensure whether there is any alarm

on the station and all the faults is

removed; Test whether the status of

cell is normal.

Select testing route Testing route tries to across the

area covered by tested base station.

Try to cover all the streets aroundtested base station.

Local driving habits should taken

into account in order to shorten the

waiting time for traffic light.

Select testing point Try to meet the requirement of

signal coverage: RSCP >= -

75dBm；Ec/Io >=-8dB

Check all the testing equipments

Base station status check

Whether any alarm occurs on the

station or not; If the station is

blocked or not.

Whether HSPA function of the cell is

activated or not.

Whether other network elements

(MSC, SGSN, GGSN, PDN Server,transmission) are normal or not.

Export RNC configuration table with

various basic configuration data of

base station (LAC, RAC, CELLID,

frequncy, scrambling code, CPICHPOWER, neighborhood, etc.)

Cooperate with installation engineer

to check and solve fault.

Single Station Verification Tool ConfigurationF852 (M bil h )



F852 (Mobile phone)

SupportsHSDPA/UMTS

Supports

EDGE/GPRS/GSM

Supports HSDPA of3.6Mbps

Supports R99 PS

downlink with 384kbpsMF632 (Data card)

SupportHSUPA/HSDPA/UMTS

Support

EDGE/GPRS/GSM

Support HSDPA of7.2Mbps

Support HSUPA of 2Mbps

Support receive

classification

Contents of Single Station Verification



Parameter

check when

UE is id le

Frequency and scrambling code are consistent with theplanned data

LAC/RAC is consistent with the planned data

Cell selecting and reselecting parameter configuration

Neighborhood list is consistent with the planned data

Pilot

frequencycoverage

testing

Keep the vehicular speed on 30km/h～40km/h

Check CPICH RSCP and CPICH Ec/Io received by Scanner are

abnormal or not

Check whether there is problem, such as amplifier abnormality,antenna feeder connection abnormality, unreasonable installation

location of antenna, building block caused by changing of surrounding

environment and downward tilt angle/direction angle of antenna being

not consistent with the planned data when hardware installation.

Base

station

service

function

testing

Voice service testing

Video Call service testing

R99 and HSPA FTP data service testing

Testing Entries of Single Station VerificationN E t i C it i f A t



No. Entries Criterion of Assessment

1 Check the parameters when UE is under

idle mode

Be consistent with planned data or not

2 Check coverage testing result of Scanner

(CPICH RSCP and Ec/Io)

In the range of 100m near base station, CPICH

RSCP>-75dBm, Ec/Io>-6dB。

3 Check coverage area of Scanner The signal of each antenna direction is normal or not.The coverage range of each antenna direction is

consistent with planned data (exclude the possibility

of wrong connection of antenna feeder)

4 Voice Call Calling and called of voice service are normal or not.

Voice call quality is normal or not

5 Video Call Calling and called of video call service is normal or

not. Video call quality is normal or not.

6 PS384K FTP uplink average throughput

testing

PS384K UL Average Throughput > 300kbps

6 PS384K FTP downlink averagethroughput testing

PS384K DL Average Throughput > 300kbps

7 HSDPA FTP average throughput testing

(HSDPA 7.2M)

HSDPA Average Throughput > 5M （测试条件

CQI>=24 ）

8 HSUPA FTP average throughput testing

( HSUPA 2M)

HSUPA Average Throughput > 1.5M （与HSDPA测试

相同的条件下进行）

Base Station Cluster Optimization



When there are non-completion or faulted base station inWCDMA network, selecting several normal base stations ina certain range of area to compose sub network to dooptimization can reduce complexity of network optimization.Pay attention to make the degree of boundary overlap ofthe sub network corresponding to single station coveragetest results.

Base station optimization is a cyclic process. The flow ofbase station optimization is shown below:

Determine optimization area and target Determine testing route

Carry out full drive test

Analyze measurement data, form adjusting plan and carry outthe plan

Judge whether the adjusting result can meet the expectedgoal. If the result cannot meet the expected goal, the processshould return.

Judge whether all the base station optimization is completed.If the optimization is not completed, the process should return.

Enter the stage of whole network optimization.




The advantage of base station cluster optimization

includes:

Locating and solving the network problems regionally.

Facilitating to carry out parallel optimization bygrouping.

Facilitating to monitor work progress

Minimizing data processing time of tool




Base station cluster optimization steps:

Determine the size and location of the base station

Determine the items of base station cluster being

analyzed Coverage, scrambling, size and location of handover;

neighbor cell list evaluation; access, handover and call

drop.

Carry out the test

Drive Test: Ec/Io, Pilot Power, UE TX Power, Neighbors,

Call Success/Drops and Handover statistics；Service

allocation, FER/BLER, Max and Av. BER , Throughput,Delay

Premise of Base Station Cluster Optimization



Cluster division is completed. And more than 80% of basestations in the cluster has been launched and passed single

station verification.

Test route design inside clusters is completed.

Neighbor cell allocation inside clusters has been completed.

Define the adjustment means permitted in the progress of

optimization.

Documents needed to be input before cluster optimization:station exploration and designing report, single station

verification report, station engineer parameter table, OMCR

configuration data.

Optimization tools preparation: test software, analysis

software, HSPA data card, scanner, notebook computer,

electric map, vehicle inverter, GPS, test cars, and so on.

Division of Base Station Cluster



Principle of cluster division

topography and

geomorphology

service distribution the same information of

RNC, LAC area, etc.

Method of cluster division

Every cluster includes

less than 15~30 base

stations. It should not be

too much.

Coverage areas

between clusters has

their overlaps.

Base Station Cluster Planning Testing Route



Testing route should cross all the launched sites inthe cluster;

Main road and highway in the cluster should be

selected; If the sites beside the cluster is isolated islands, the

testing route near these sites should be the sites with

Ec>-100dBm;

Testing route should have overlaps with neighbor

cluster

Testing route should try to avoid to cross the

unlaunched sites in order to guarantee the continuouscoverage of testing route.

Testing route should indicate the direction of car

driving.

Work Flow of Base Station Cluster OptimizationInput



Engineering

parameter list

System parameter

list

Digital mapSingle station

verification report

Preparation of

documents and tools

Definition of clusters

and DT route

Cluster

optimization plan

Initial cluster

coverage testing

Problem analysis

Optimization advice

Executing

Verifying

Y

Problem

solved?

N

Optimization flow

Over coverage

Pilot pollution

Call drop

Handover failure

Block

Scambling……

Commit report

List of adjustment

of parameters and

antenna feeder

Cluster

optimization

report

Update

engineering

parameters list

Update system

parameters

End

Pass the

verification?

Output

Y

N

Main Content of Base Station Cluster

Optimization Being Analyzed



Leading cells analysis

Coverage analysis (CPICH Ec, Ec/Io)

Pilot frequency pollution analysis

Scrambling analysis

Neighbor cell analysis

Soft handover analysis Access problem analysis

Call drop analysis

Whole Network Optimization



After complete the cluster optimization of base station, the systemwill work smoothly in most area of its coverage. But in some parts,

especially the overlap area of sub-networks and some signal blind

area, network should be adjusted by taking every performance

index into consideration in order to complete global networkoptimization.

Whole network optimization is also a recycling procedure. It

includes:

Determine optimization area and projects Determine the test route

Make an all-round drive test

Analyze the test results to form and carry out adjustment

planning Check whether the adjustment has reached the supposed

result. Otherwise, return.

Commit the optimization report.

Whole Network Optimization Work Contents



Optimization of cluster boundary and RNC border isthe key of this period. It can guarantee the completion

of the global network.

Solve the problems without being located in the periodof cluster optimization; solve the problems located but

might be influenced by the optimization adjustment;

and solve the newly-located problems.

Hard handover optimization should also be completed

in the period of global network optimization.

Evaluate and optimize the radio performance of the

global network by means of drive test, so as to makeevery network index meet the users’ requirements

before commercial numbers allocated.

Whole Network Optimization Preliminary

Acceptance Standards



requirements (examples) Acceptance item Meaning

Scopeproposed

value

CPICH RSCP Coverge Rate (optional) Pilot frequency coverage intensity ≥-95dBm ≥98%

CPICH Ec/Io Coverage Rate (optional) Pilot frequency coverage quality ≥-14dB ≥98%

Voice call setup success rate Voice call setup success rate Min % ≥98%

Voice call drop rate Voice call drop rate Max % ≤2%

Video call setup success rate Video call setup success rate Min % ≥98%

Video call setup success rate Video call drop rate Max % ≤2%

PS 128k DL Mean ThroughputPS128k downlink mean

throughoutMean 110kbps

HSDPA Mean Throughput HSDPA Mean Throughput ≥1Mbps ≥90%

Because there is almost no user in the network on the project acceptance stage, several testing

routes are chosen used for drive test when verifying. Through DT index, we can determine whether the

network can pass the verification.

Whole network verifying test executes on the condition that the local cells and neighbor cells

have 50% of downlink loading.

Content




optimization

General flow of WCDMA radio network

optimization



D l i

D t l sis

Operation and Maintenance Optimization Period



NO YES

Network performancemonitoring

Network performancemonitoring

Data analysisData analysis

Planning designoptimization

Planning designoptimization

Carrying out planningCarrying out planning

Planning verificationPlanning verification

DT CQT

OMC Complain

Improve the network quality, improve the customer’s degree of satisfaction

Operation and Maintenance Optimization



Objectives of post-launch operation andmaintenance optimization:

Improving the QoS

Increasing the system capacity

Increasing the coverage range of the service (for

example, increasing the coverage range of high-

speed data service) Providing better service for hot-spot areas

Maximizing the return of the investment

Operation and Maintenance Optimization



The major work contents of the post-launchoperation and maintenance Optimization include:

Adding base station

Further sectorizing existing base station

Optimizing the parameters

Reducing the interference

Using more than 1 carriers

Implementing the layered cell structure

Providing the solution for indoor coverage

Operation and Maintanence Optimization

St t



Flow for network

operation analysis

Network operation analysisis suitable for a network in

formal operation. OMC

performance statistic data

can be extracted andanalyzed periodically,

possible equipment and

network problems can be

analyzed and then networkoperation analysis report can

be submitted to provide a

reference for the customer’s

network adjustment and

optimization.

Start

Retrieve backgrounddata

OMC engineer

Analyze data andnetwork

performanceOptimization engineer

Backgroundstatistics data

Networkrunninganalysisreport

End



Significant Attention KPI



Example of KPI monitoring of Daily Operation

and Maintenance



Advice on Wide Centralized Optimization



After network expanded widely After new station established, RF optimization, neighborhood optimization

(inside and between systems), and parameter optimization of reselection andswitching are needed. If new carriers are added, parameter optimization ofreselection and switching between carriers, parameter of load control and loadbalancing are also needed.

Obvious quality reduction of network or increase of user complaints caused bysome poor KPI(s) which cannot meet the requirements

When access success rate, call drop rate, paging success rate and PSdownload rate worsen user experience index directly, wide optimization,problem tackling and index improvement are needed.

Great changes occur to radio network. State of vegetation changes according to seasons; changes occur to radio

network due to city development and building. Great changes occur to network capacity.

As the number of users increase quickly, network performance index will beworsened obviously. Under such circumstances, wide optimization is needed toimprove network performance under high load.

Principal business changes Optimization will be needed when principal business changes, for instance,

audio/video telephone changes into high speed PS business (such as HSDPA).

Key technique changes Optimization will be needed when network mode transfers from OTSR to STSR

with the technique of MIMO.

Operation and Maintenance Optimization Flow 1

Start



Performanceindexcollection

RNC indexabnormal?

Equipment

alarm exists?

Equipmentalarm process

RNC indexduplicates?

Sudden orself-recoverableabnormal?

Reason analysisand record

Advice onimprovement

Y

N

Y

Y

NN

N

Y

Abnormal cell TOPN

and geographic display

1 2 3

Weather change, holiday,

gathering, instantaneous

transmission turnoff,

power problem, etc.

Operation and Maintenance Optimization Flow 2



Optimization of Access Rate of the Radio System



Optimization Flow of Call Drop Rate of the Radio

System1. RNC Call Drop Rate

Analysis



2. Cell Call Drop Rate

Index Analysis

3. Check Cell Equipment is

abnormal?

4. Analyze the causes of

call drop.

4.1 Call drop caused by signalRB reset or service RB reset?

4.2 Call drop caused by cut-

over?

4.3 Call drop caused by

scrambling?

5. Represent the problems

through Drive Test

Solve the problem of

equipment

Solve the problem ofcoverage


handover call drop


scrambling

End

YES

NO

YES

YES

YES

NO

NO

NO

WPO-13 WCDMA Radio Network Optimization-86

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Transcript of WPO-13 WCDMA Radio Network Optimization-86