OWO300010 WCDMA UTRAN Optimization Flow ISSUE1.11.pdf

7/29/2019 OWO300010 WCDMA UTRAN Optimization Flow ISSUE1.11.pdf

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Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA UTRANOptimization Flow


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Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. Page2

Foreword

WCDMA optimization is a very important part in the lifecycle of

the network.

Mainly, the optimization includes the preparation, single site

verification, RF optimization and parameters optimization.


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Contents

1. Introduction of Optimization Flow

2. The Preparation for the Optimization Project

3. Single Site Verification

4. RF Optimization

5. Parameters Optimization

6. Optimization Report


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Contents


2. The Preparation for the Optimization Project


4. RF Optimization




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WCDMA Optimization Flow

Project Start

Single Site

Verificaiton

Preparation and

Startup

RF

Optimization

Parameter

Optimization

Acceptance and

Report

Network Information

Collection

Cluster Division and

Team Establishment

Optimization Tools

Preparation

Drive Test and RNC

Configuration Collection

Trouble shooting

Engineering Parameter

Adjustment Preparation

Data Collection

DT and Statistic

Analysis Parameter Adjustment


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Introduction of Optimization Flow

Final Documents:

SSV Reports

Optimization Report

Engineering Parameter Table

Cell Parameter Table

Process Documents:

Engineer Parameter Table

Cell Parameter Table

Parameter Changing Record


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Contents


2. The preparation for the Optimization Project


4. RF Optimization




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WCDMA Optimization Flow - Preparation

Project Start

Single Site

Verificaiton

Preparation and

Startup

RF

Optimization

Parameter

Optimization

Acceptance and

Report

Network Information

Collection


Team Establishment

Optimization Tools

Preparation

Drive Test and RNC


Trouble shooting



Data Collection

DT and Statistic



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The Preparation for Projection

The following work is required:

Understanding of the Existing Network

Cluster Division and Optimization Team Establishment

Optimization Tools and Software


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The Preparation for Projection

Understanding of the Existing Network :

Radio Network Planning report

Latest engineering parameter table and cell parameter table

OMC statistic data

Subscriber complaints

Historical Optimization Reports


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The Preparation for the

Optimization Projection Cluster Division

One cluster should cover one continuous area, which isconvenient for one time drive test;

Cluster division should consider the terrain, administration and

main roads.


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The Preparation for the Optimization Projection

Optimization Team Establishment

RNO leader-1

Data Analyzer

Drive Test Operator

Driver

RNO leader-n

Data Analyzer

Drive Test Operator

Driver

..................

RNO manager


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The Preparation for the Optimization Projection

Optimization Tools

Hardware

UMTS Scanner

UMTS Test UE

GPS and data line

Laptop

Digital camera Spectrum analyzer

Software:

DT tools

Post processing tools

MapInfo

Google earth


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Contents




4. RF Optimization




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WCDMA Optimization Flow Single SiteVerification

Project Start

Single Site

Verificaiton

Preparation and

Startup

RF

Optimization

Parameter

Optimization

Acceptance and

Report

Network Information

Collection


Team Establishment

Optimization Tools

Preparation Drive Test and RNC


Trouble shooting



Data Collection

DT and Statistic



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Single Site Verification

Purpose: The single site verification test is a part of the WCDMA network

optimization to ensure that the basic functions of the cell are normal,

such as call access, call quality, handover and so on.

Single site verification involves the following aspects: Parameter setting check in idle mode

Services call (AMR/VP/PS) function check in connected mode

HSDPA function check

CPICH RSCP & Ec/Io Installation problems check


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Single site verification includes :

preparations before test

single site test

solving problems

The single site verification is completed by:

On-site engineers

RNO engineers


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Single Site Verification - Tasks of the

on-site engineers

Application key

Preparations Site Status Check

For each cell to be measured, check Status by LMT or M2000

Configuration Data Collection and Check

check whether the data configured is consistent with the planned data

Testing Point Selection

Test UE Setup

Set the UE to testing mode before test Other Preparations


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on-site engineers

Verification in Idle Mode

Frequency Check

Check whether the frequency is consistent with the planned data

Scramble Check

Check whether the scramble is consistent with the planned data

LAC/RAC Check

Check whether the LAC/RAC is consistent with the planed data.

CPICH_RSCP / CPICH_Ec/Io (Near Site) Test Check whether the CPICH RSCP and CPICH Ec/Io received by UE are

greater than the threshold


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on-site engineers

Verification in connected Mode Originating and Terminating Call of Voice Service

Check whether the originating and terminating function of voice

service function normally by call quality test

Originating and Terminating Connection Test of VP Service Check whether the originating and terminating function of VP

service function normally by call quality test

Access Test of PS Services

Check whether the PS services access are normal Solving Problems


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Single Site Verification Task of the

RNO engineers

Preparations

Cell Status Confirmation

Before checking site, you need to inquiry product support engineers

whether the cell is in normal status

Testing Route Selection

Before test, you must select a proper testing route according to site

distribution and local environment

Testing Tools

Hardware

Software


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RNO engineers

Coverage Check Check whether CPICH RSCP and CPICH Ec/Io received by scanner is

normal

Inconsistency of antenna tile/direction angle from planned one

Check whether the RX ports of different cell are reversely

connected

Fixed Maximum Transmit Power of UE, measure the RTWP of the cells in

OMC room

Checking Antennas by Exchanging Feeders, measure the RSCP before

and after.


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RNO engineers

Service Function Test

MOC and MTC of Voice call

MOC and MTC of VP

UL and DL R99 PS service

HSDPA access function and throughput test

HSUPA access function and throughput test


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RNO engineers

Solving Problems

If RNO engineers find out some installation problem, ask the

installation team fix it and do retest to verify If RNO engineers find problems about product function, RNO

engineers must ask RAN engineers help to solve problems


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Summarization:

In single site verification stage, engineers check whether

equipment functions are normal

Single site verification is a basis for the following RF optimization

and Parameter optimization

If all verifications about function are accepted, the single site

verification is completed


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Contents




4. RF Optimization




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WCDMA Optimization Flow RF

Optimization

Project Start

Single Site

Verificaiton

Preparation and

Startup

RF

Optimization

Parameter

Optimization

Acceptance and

Report

Network Information

Collection


Team Establishment

Optimization Tools



Trouble shooting



Data Collection

DT and Statistic



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RF Optimization - Overview

Once all the sites on-air and verification is completed, RF optimizationstarts

During the RF optimization stage, you willoptimize radio frequency

(RF) signals , so that the distribution of radio signal is normal in next

stage -- parameters optimization

RF optimization includes the following aspects:

Coverage optimization

Pilot pollution optimization

Handover optimization


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RF Optimization flow


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RF Optimization - Preparation (1)

Define Optimization targets Weak coverage

Pilot pollution

SHO Factor based on DT

Define Test Route

Cluster Division

Preparing Tools and Data

Preparing Software Preparing Hardware

Engineering and cell Parameter table


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Index Reference Remarks

CPICH Ec/Io 9dB

97% in urban area According to test result from the scanner, in

unloaded and outdoor conditions, in planning

coverage areas, test in a grid-like route to cover all

cells. 97% in suburban

area

CPICH RSCP

95dBm

98% in urban areaAccording to test result from the scanner, in

unloaded and outdoor conditions, in planning

coverage areas, test in a grid-like route to cover all

cells. The coverage level request is basic. If

operators have penetration loss request, add the

penetration loss to the coverage level.

95% in suburban

area

SHO Factor based on

DT 30%40%

The SHO Factor based on DT should be 5% to

10% lower than the goal, because the following

optimizations cause the soft handover factor to

increase

Pilot pollution ratio 5%

RF Optimization - Targets


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Dividing Clusters

RF optimization must be performed on a group of or a cluster of

NodeBs , and to ensure that interference from intra-frequency

neighbor cells are considered during optimization.

Define Test Route

The test route should cover all sites, all main roads and VIP area.


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RF Optimization - Preparing Tools and Data:

Software

Genex Probe

Genex Assistant

Mapinfo

Google earth

Device

Scanner

Test terminal and dataline

GPS and data line

Laptop

Vehicle mountedinverter

Needed data

List of engineeringparameters

Map

KPI requirements

Network configurationparameters

Survey report

Single site verification

checklistFloor plan of the targetbuildings


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RF Optimization - Data Collection

DT is a major test. Collect scanner and UE data of radio signals

by DT test

Usually the DT and indoor test during RF optimization stage is

based on VP service.

During RF optimization stage, collect neighbor cell data of

network optimization and other data configured in RNC

database


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RF Optimization - RF problem solutions

Antenna tilt

Antenna azimuth

Antenna location

Split sector

Remove sector

Combine sector

Antenna height

Antenna type

TMA RRU

Site location

New site


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RF Optimization

Some advices:

Before the RF adjusting, wed better survey the relative sites, and

give some applicable advice

If possible, do the RF adjustment and test the effect at the sametime


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RF Coverage Problem Analysis

The coverage problems to be analyzed include:

Weak coverage

Overshoot coverage

Unbalance between uplink and downlink

No dominating cell


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Coverage Analysis Processes:

Downlink Coverage Analysis

Analyzing Pilot Strength

Analyzing Pilot quality

Analyzing Dominate Cell

Analyzing comparison of UE and Scanner Coverage

Uplink Coverage Analysis

Analyzing Uplink Interference

Analyzing distribution of UE Transmit Power


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Downlink coverage analysis Pilot Strength Analysis

Check areas of weak coverage, suggestion value as below:

Good: RSCP -85 dBm

Fair: -95 dBm RSCP 10 dBm

Assume the optimization indexes of UE transmit power as below:


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The distribution of UE transmit power

UplinkUplink Coverage - Distribution of UE Transmit Power

The distribution of UE transmit power reflects the distribution

of uplink interference and uplink path loss


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Pilot Pollution Problem Analysis

Pilot Pollution Point Definition:

The pilot pollution is that excessive strong pilots exist in a point

but no pilot is strong enough

Pilot pollution exists if all the following conditions are met:

The number of pilots that meet the following condition is more than 4

and CPICH_RSCP > -100dBm

(CPICH_RSCP1st - CPICH_RSCP 4th)< 5dB


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Influence of Pilot Pollution :

Pilot pollution causes the following network problems:

Ec/Io Deterioration

Call Drop Due to Handover

Capacity Decline


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-62-63

-64-66 -67

-81

-90

-85

-80

-75

-70

-65

-60

SC1 SC2 SC3 SC4 SC5 SC6

RSCP

(dBm)

Active Set Pilot Pollution

Margin

NotPilot Pollution

Pilot Pollution Definition - J udgment Standards :


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Pilot Pollution - Estimated Active Set Size:


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SC Count % in Pollution Set

8 206 12.9%

9 165 10.3%

10 157 9.8%

11 156 9.7%

12 148 9.2%

13 135 8.4%

16 95 5.9%

17 94 5.9%

18 76 4.7%

19 74 4.6%

20 73 4.6%

21 56 3.5%

32 54 3.4%

35 39 2.4%

37 33 2.1%

43 19 1.2%48 8 0.5%

53 7 0.4%

67 3 0.2%

80 2 0.1%

130 2 0.1%

Should be investigated

Pilot Pollution - Estimated Active Set Size

Pilot pollution results


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Causes of Pilot Pollution :

Improper Cell Distribution

Over High NodeB or Highly-mounted Antenna

Improper Antenna Azimuth

Improper Antenna Down Tilt

Improper CPICH Power

Ambient Factors


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Process for Analyzing Pilot Pollution

Analyze scanner-based RSCP for 1st Best Service Cell and Ec/Io for

1st Best Service Cell

Analyze scanner-based Whole PP

Locate the cells that cause pilot pollution of the key areas.

Judge whether the pilot pollution is caused by existence of

multiple strong pilots or lack of a strong pilot

Confirm the cells that need eliminating the coverage of an area

and that need enhancing the coverage of an area

Retest after adjustment


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Solutions of Pilot Pollution :

Antenna Adjustment

PCPICH Power Adjustment

Using RRU or Micro Cells


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Handover Problem Analysis

By adjusting RF parameters ,we can Control the size and location of

handover areas ,then we can eliminate handover call drop due to

sharp fluctuation and increase handover success rate.

During RF optimization stage, the involved handover problem include:

Neighbor cell optimization

Controlling SHO Factor based on DT

H d P bl A l i N i hb


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Handover Problem Analysis - Neighbor

cell optimization

The neighbor cell optimization includes adding and removingneighbor cells.

Add: Missing neighbors

Remove: The neighbors are never measured but in the neighbor

list.

Neighbor cell optimization can be analyzed by :

Scanner Data

UE Data Analysis

Careful consideration is needed prior to removing neighbours

H d P bl A l i N i hb


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cell optimization By the scanner data, the Assistant can generate a neighbor cell

analysis report in the format of Excel

Handover Problem Analysis Neighbor


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cell optimization

We can also analyze a missing neighbor cell by UE DT data

The daemon analysis tool can seldom analyze UE data

automatically and generate missing neighbor cells

but we can Compare the active set Ec/Io distribution diagram

measured by UE and that measured by scanner

The spots with missing neighbor cells has a poor Ec/Io

measured by UE and a strong Ec/Io scanned by scanner .


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Controlling SHO Factor based on DT: According to the DT data from scanner, you can obtain the SHO

Factor based on DT, defined as below:

DTinpointscollectedscannertotalofNumberconditionshandovermeet thethatDTinpointscollectedscannerofNumberRatioHandoverSoft

The SHO Factor based on DT during RF optimization

stage must be 5%

10% lower than the KPI target

value


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UE SHO Performance

The success rates for event 1a, 1b & 1c and can be obtained from

softwareNumber of Active Set Updates

Event Count

Event 1a - 328

Event 1b - 306Event 1c - 64

Number of Active Set Update Completes

Event Count

Event 1a - 326

Event 1b - 305Event 1c - 62

Soft-Handover Success Rate

Event Rate

Event 1a - 99.4

Event 1b - 99.7Event 1c - 96.9


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RF Analysis Approaches Neighbor List

Controlling SHO Factor based on DT

If the SHO Factor based on DT is over large, decrease or change

the handover areas by using the following methods for shrinking

coverage areas:

Increase the down tilt

Adjust azimuth

Decrease the antenna height

Decrease the PICH power


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Contents




4. RF Optimization



WCDMA Optimization Flow Parameter


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WCDMA Optimization Flow Parameter

OptimizationProject Start

Single Site

Verificaiton

Preparation and

Startup

RF

Optimization

Parameter

Optimization

Acceptance and

Report

Network Information

Collection


Team Establishment

Optimization Tools



Trouble shooting



Data Collection

DT and Statistic



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Purpose of Parameters Optimization

Purpose of parameters optimization

Decrease the access success ratio

Decrease the call drop ratio

Increase the quality of service

The tools data and tools for analysis:

Drive test data and analysis tools

Statistic data and analysis tools RNC trace and logs data

MSC & SGSN record if necessary


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Drive test The contents of drive test

Idle mode test

The short call test for voice service

The continuous call test for voice service

The short call test for video phone service

The continuous call test for voice service

The access test for R99 PS service

The continuous call test for R99 PS service

HSDPA FTP download test

The test should be performed repeatedly to the position withproblems to make sure that the problem is repeatable


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Drive Test Data Analysis

Drive Test Data Analysis

Analyzing and finding out the solution for access failure

Analyzing and finding out the solution for drop call

Analyzing and finding out the solution for service quality relatedproblems

Adjustment Recommendation and


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Adjustment Recommendation and

Implementation

Adjustment Recommendation and Implementation

Common Control Channel Power Allocation parameters

RL Maximum Power parameters

Intra-frequency Handover parameters Inter-frequency Handover parameters

Inter-RAT Handover parameters

Power Control parameters

Access parameters

Other related parameters


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Test for Special Areas

Special area refers to a small district or indoors environment

Operator offices, residence of VIP

Key hotels or entertainment location

Government location

Locations of large company or group subscribers

Locations tend to be cared , such as railway station or airport


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Contents

1. Introduction of Optimization Flow2. The preparation for the Optimization Project


4. RF Optimization5. Parameters Optimization


WCDMA Optimization Flow Optimization


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WCDMA Optimization Flow Optimization

Report OutputProject Start

Single Site

Verificaiton

Preparation and

Startup

RF

Optimization

Parameter

Optimization

Acceptance and

Report

Network Information

Collection


Team Establishment

Optimization Tools



Trouble shooting



Data Collection

DT and Statistic



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Optimization Report

The optimization report should include: Project background introduction

Existing network status

Acceptance criteria

Optimization process

Problem analysis and adjustment recommendation, and the effect

for the implemented part

Acceptance test and result

Leftover problems and suggestions from the optimization point of

view.


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Thank youwww.huawei.com

OWO300010 WCDMA UTRAN Optimization Flow ISSUE1.11.pdf

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