01 OWJ200101 WCDMA UTRAN Optimization Flow (With Comment) ISSUE1.0

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Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA UTRAN Optimization Flow


Foreword

� WCDMA optimization is a very important part in the life of

the network.

� Mainly, the optimization contents the preparation, single site

verification, RF optimization, parameters optimization.


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


WCDMA Optimization Flow


Introduction of Optimization Flow

� Customized Document:

� Acceptance Report

� Optimization Report

� Site Configuration Parameter Table

� Radio Part Parameter configuration Table

� Process Document and Data:

� Site configuration Parameter Table

� Radio part Parameter configuration Table

Output document:


Contents




4. RF Optimization




WCDMA Optimization Flow - Preparation


The Preparation for Projection

� The following work is required:

� Understanding of the Existing Network

� Cluster Division and Optimization Team Establishment

� Optimization Tools and Software



� Understanding of the Existing Network :

� Radio Network Planning report

� Latest site configuration parameter table and radio part

parameter configuration table

� OMC statistic data and subscriber complaints of the existing

network


The Preparation for the Optimization Projection

� Cluster Division and Optimization Team Establishment

RNO leader-1

Data Analyzer

Drive Test Operator

Driver

RNO leader-n

Data Analyzer

Drive Test Operator

Driver

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

RNO manager



� Optimization Tool:

� UMTS Scanner

� UMTS Test UE

� GPS and data line

� Digital camera

� spectrum analyzer

� Optimization Software:

� Post processing

tool

� MapInfo


Contents




4. RF Optimization




WCDMA Optimization Flow – Single Site Verification


Single Site Verification

� Purpose:

� The single site verification test is a part of the WCDMA networkoptimization 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

� Installing problems check



� Single site verification includes :

� preparations before test

� single site test

� solving problems

� The single site verification is completed by:

� On-site engineers

� RNO engineers


Single Site Verification - Task of the on-site engineers � Preparations

� Site Status Check

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

� Configuration Data Collection and Check

� check whether the data configured is consistent with the planned data

� Testing Point Selection

� Test UE Setup

� Set the handset to testing mode before test

� Other Preparations

Application key


Single Site Verification - Task of the on-site engineers� Verification in Idle Mode

� Frequency Check

� Check whether the frequency number of the cell to be measured is consistent with the planned data

� Scramble Check

� Check whether the scramble configuration is consistent with the planned

configuration

� LAC/RAC Check

� Check whether the LAC/RAC of the cell to be measured is consistent with the planed one.

� 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


Single Site Verification - Task of the on-site engineers� Verification in connect Mode

� Originating and Terminating Connection Test 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

� Connection Test of PS Services

� Check whether the originating function of PS services are normal by handset online service

� Solving Problems

� If on-site engineers find product function problems or parameter configuration problems, the engineers must location them and retest until the problems are solved and process terminates.


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

� Precautions


Single Site Verification – Task of the RNO engineers� Coverage DT Check

� Check whether CPICH RSCP and CPICH Ec/Io received by

scanner is normal

� Abnormal power amplifier

� Abnormal connection of antenna-feeder

� Inconsistency of antenna tile/direction angle from planned one

� Blocking by buildings


Single Site Verification – Task of the RNO engineers

� HSDPA Access Function Test

� To test HSDPA access function

� Check whether the antenna for receiving diversity signals is

reversely connected

� Fixed Maximum Transmit Power of UE, measure the RTWP of

the cells

� Checking Antennas by Exchanging Feeders


Single Site Verification – Task of the RNO engineers

� Antenna Diversity Check

� The method for UE to transmit signals at the fixed maximum

power is a recommended method of test and operation

� Solving Problems

� If RNO engineers find problems about product function, RNO

engineers must ask product support engineers to solve

problems



� Summarization:

� In single site verification stage, engineers check whether

equipment functions normally

� Single site verification is a basis for the following RF

optimization and service optimization

� If all verifications about function are accepted, the single site

verification is completed

� After single site verification, optimization comes to RF

optimization


Contents




4. RF Optimization




WCDMA Optimization Flow – RF Optimization


RF Optimization - Overview

� Once all the sites are installed and verification is complete, RF

optimization starts.

� During the RF optimization stage, you will optimize radio

frequency (RF) signals , so that the distribution of radio signals is

normal in next service -- parameters optimization stage

� RF optimization includes the following aspects:

� Coverage optimization

� Pilot pollution optimization

� Handover optimization


RF Optimization flow


RF Optimization - Preparation (1)� Deciding Optimization target

� Weak coverage

� Pilot pollution

� High SHO Factor based on DT

� Dividing Clusters

� Deciding Test Route

� Confirm the KPI DT acceptance route with the operator before

DT

� Preparing Tools and Data

� Preparing Software

� Preparing Hardware

� Preparing Data


RF Optimization - Preparation (2)

–≤ 5%Pilot pollution ratio

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

30%–40%SHO Factor based on DT

≥ 95% in suburban 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. The coverage level request is basic. If operators have penetration loss request, add the penetration loss to the coverage level.

≥ 98% in urban area

CPICH RSCP ≥ –95dBm

≥ 97% in suburban 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 urban area

CPICH Ec/Io ≥ –9dB

RemarksReferenceIndex

RF Optimization - Targets


RF Optimization - Preparation (3)

� Dividing Clusters

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

of NodeBs ,This ensures that interference from intra-frequency

neighbor cells are considered during optimization.

� Dividing clusters involves approval by the operator.

� Deciding Test Route

� The KPI DT acceptance route is the core route of RF

optimization test routes. Its optimization is the core of RF

optimization.


RF Optimization - Preparing Tools and Data:

Mapinfo

Genex Nastar

Genex Assistant

Genex Probe

Software

Vehicle mounted inverter

Laptop

Test terminal and data line

Scanner

Device

Floor plan of the target buildings

Single site verification checklist

Survey report

Network configuration parameters

KPI requirements

Map

List of engineering parameters

Needed data


RF Optimization - Data Collection

� During RF optimization stage, the key is the optimization of radio

signals distribution, with the major means of DT and indoor test

� 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


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


RF Optimization

� Attention:

� During the RF optimization ,sometimes the problems can be

resolved completely by proper adjustment, but there is also

some disadvantages of the RF optimization

� The duration of the RF Optimization will be always very long

� Some adjustment is difficult to implement

� If the problems are not resolved by the RF optimization, it is

difficult to recover the antennas back to the former

conditions

h1

h1 考虑删除hw, 12/2/2006


RF Optimization

� Some advices:

� Before the RF adjusting, we’d better survey the relative sites,

and give some applicable advice

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

same time


RF Coverage Problem Analysis

� Coverage problem analysis is key to RF optimization. It

involves signal distribution. The coverage problems to be

analyzed include:

� Weak coverage

� Overshoot coverage

� Unbalance between uplink and downlink

� No primary pilot cell



� Coverage Analysis Processes:

� Downlink Coverage Analysis

� Analyzing Pilot Coverage Strength

� Analyzing Pilot Coverage quality

� Analyzing Primary Pilot Cell

� Analyzing comparison of UE and Scanner Coverage

� Uplink Coverage Analysis

� Analyzing Uplink Interference

� Analyzing distribution of UE Transmit Power



� Downlink coverage analysis - Pilot Coverage Strength

Analysis

� Check areas of poor coverage, suggestion value as below:

� Good: RSCP ≥ -85 dBm

� Fair: -95 dBm ≤ RSCP < -85 dBm

� Poor: RSCP < -95 dBm

� Mark the areas with weak coverage or common seamless

coverage of large areas for further analysis


RF Coverage Problem AnalysisDownlink coverage analysis - Pilot Coverage Strength Analysis



� Downlink coverage analysis - Pilot Coverage quality

Analysis

� Ec/Io plot should also be analysed based on the thresholds :

� Good: Ec/Io ≥ -8 dB

� Fair: -14 dB ≤ Ec/Io < -8 dB

� Poor: Ec/Io < - 14 dB

� Areas of poor Ec/Io should be highlighted for further

investigation



-15.5

-104

-20

-19

-18

-17

-16

-15

-14

Ec/Io RSCP

-120

-115

-110

-105

-100

-95

-90 What’s the problem?

Downlink coverage analysis - Pilot Coverage quality A nalysis:



-15.5

-63

-20

-19

-18

-17

-16

-15

-14

Ec/Io RSCP

-90

-85

-80

-75

-70

-65

-60

What’s the problem?

Downlink coverage analysis - Pilot Coverage quality A nalysis:


RF Coverage Problem AnalysisDownlink coverage analysis - Analyzing Primary Pilot Cell:



� Downlink coverage analysis - Analyzing Primary Pilot Cell:

� Cell primary pilot analysis is analyzing cell scramble

information obtained in DT

� The content to be checked include :

� Weak coverage cell

� Cross-cell coverage cell

� No primary pilot cell


RF Coverage Problem AnalysisDownlink coverage analysis - Analyzing Primary Pilot Cell:


RF Coverage Problem AnalysisDownlink coverage analysis - Analyzing comparison of UE and Scanner Coverage :

Inconsistent Best Service Cell between scanner and UE


RF Coverage Problem Coverage Problem AnalysisAnalysis

� Uplink coverage analysis is analyzing UE transmit power obtained in DT.

� The quality standards of UE transmit power must be combined with optimization

standards.

� Assume the optimization indexes of UE transmit power as below:

The test result of voice service by test handset. Assume the maximum transmit power of UE is 21 dBm

>= 95%UE_Tx_Power≤ 10 dBm

� The defined corresponding quality standards are:

� Good if UE_Tx_Power ≤ 0 dBm

� Fair if 0 dBm < UE_Tx_Power ≤ 10 dBm

� Poor if UE_Tx_Power > 10 dBm

Uplink coverage analysis:


RF Coverage Problem Coverage Problem AnalysisAnalysisUplink - Distribution of UE Transmit Power:

The distribution of UE transmit power reflects the distribution of uplink interference and uplink path loss

The distribution of UE transmit power


Pilot Pollution Problem Analysis

� Pilot Pollution Point Definition:

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

but no primary 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


Pilot Pollution Problem Pilot Pollution Problem AnalysisAnalysis

-62 -63 -64 -66 -67

-81

-90

-85

-80

-75

-70

-65

-60

SC1 SC2 SC3 SC4 SC5 SC6

RS

CP

(dB

m)

Active Set Pilot Pollution

Margin

NotPilot Pollution

Pilot Pollution Definition - Judgment Standards :


Pilot Pollution Problem Pilot Pollution Problem AnalysisAnalysisPilot Pollution Definition - Estimated Active Set Size Example Estimated Active Set Size Example :


Pilot Pollution Problem Pilot Pollution Problem AnalysisAnalysis

S C C o un t % in P o llu tio n S et8 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 investigatedShould be investigated

Pilot Pollution Definition - Estimated Active Set Si ze Example :

Pilot pollution results



� Causes of Pilot Pollution :

� Improper Cell Distribution

� Over High NodeB or Highly-mounted Antenna

� Improper Antenna Azimuth

� Improper Antenna Down Tilt

� Improper PICH Power

� Ambient Factors



� Influence of Pilot Pollution :

� Pilot pollution causes the following network problems:

� Ec/Io Deterioration

� Call Drop Due to Handover

� Capacity Decline



� 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



� Solutions of Pilot Pollution :

� Antenna Adjustment

� PCPICH Power Adjustment

� Using RRU or Micro Cells


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


Handover Problem Analysis -Neighbor cell optimization � During RF optimization stage, missing neighbor cell is a key problem. The

neighbor cell optimization includes adding and removing neighbor cells

� Add: Missing neighbors

� Remove: These neighbors that were not measured but are in the neighbor list.

Careful consideration is needed prior to removing n eighbours

� Neighbor cell optimization can be analyzed by :

� Scanner Data

� UE Data Analysis


Handover Problem Analysis Handover Problem Analysis -- Neighbor Neighbor cell optimizationcell optimization� By the scanner data, the Assistant can generate a neighbor cell

analysis report in the format of Excel


Handover Problem Analysis - Neighbor 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 .


Handover Problem Analysis

� According to the DT data from scanner, you can obtain the

SHO Factor based on DT, defined as below:

Controlling SHO Factor based on DT:

DTin points collected-scanner totalofNumber

conditionshandover meet the that DTin points collected-scanner ofNumber ＝RatioHandoverSoft

� The SHO Factor based on DT during RF optimization

stage must be 5%–10% lower than the KPI target

value


Handover Problem Analysis� UE SHO Performance

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

from softwareNumber of Active Set UpdatesNumber of Active Set Updates

Event CountEvent 1a - 328Event 1b - 306Event 1c - 64

Number of Active Set Update CompletesNumber of Active Set Update Completes

Event CountEvent 1a - 326Event 1b - 305Event 1c - 62

Soft-Handover Success RateSoft-Handover Success Rate

Event RateEvent 1a - 99.4Event 1b - 99.7Event 1c - 96.9


RF Analysis Approaches – Neighbor List

� 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

Controlling SHO Factor based on DT:


Contents




4. RF Optimization




WCDMA Optimization Flow – ParameterOptimization


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 and data for analysis:

� scanner and UE

� RNC record data

� Statistic tools and KPI

� MSC & SGSN record if necessary


Drive test� The contents of drive test

� The call setup test for voice service

� The continuous call test for voice service

� Idle mode test

� The call setup test for video phone service

� The continuous call test for voice service

� The call setup test for PS service

� The continuous call test for PS service

The test should be performed repeatedly to the posi tion with The test should be performed repeatedly to the posi tion with problems to make sure that the problem is repeatabl e problems to make sure that the problem is repeatabl e


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 related

problems


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


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


Contents




4. RF Optimization




WCDMA Optimization Flow – OptimizationReport Output


Optimization Report

� The 《optimization report》 should be presented after the project passes

the customer acceptance. 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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01 OWJ200101 WCDMA UTRAN Optimization Flow (With Comment) ISSUE1.0

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