Download - Network Optimization ISSUE.ppt

8/14/2019 Network Optimization ISSUE.ppt

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OMF000501 GSM RN

Optimization ISSUE1.4

Wireless Training Department


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Concept of RN Optimization

Radio network optimization means network performance

improvement utilizing existing network resources.

Steps in general

Data collection and verification

Data analysis

Parameter and hardware adjustment

Optimization result confirm and reporting

he purpose is increasing the utilization of network resourcesand solving the existing and potential pro!lem on the network"

identifying solutions for future network planning.


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Capacity

CoverageQuality

Optimize


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Due to the mo!ility of su!scri!ers and complexity of radio

wave propagation" most of network pro!lems are caused !y

increasing su!scri!ers and the changing environments.

R# Optimization is a continuous process that is re$uired as

the network evolves


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TRAFFIC

STATISTICS

DRIVE

TEST

CUSTOMER

COMPLAINTS

OPTIMIZE

%nput for Optimization


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Concept of RN optimization

KPI of radio network

Work flow of RN optimization

Parameter adjustment principles

RN optimization tools introduction

Common problems of RN optimization

Course Contents


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KPI of Radio Network

'P% (')* P)R+OR,-) %#D%-&ORS %ndicates overall performance of network over a period of time

/ood way to monitor network trends and anticipate future pro!lems

Data o!tained from drive test and traffic statistics


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KPI of Radio Network

ypical Radio #etwork 'P%

BTS3

BTS4

BTS1

BTS2

KPI Parameter Source-all Drop Rate O,-0Drive test

-ongestion Rate Drive test

1andover Success Rate O,-0Drive test

2usy 1our raffic O,-

-1 3tilization O,-

-all Setup success rate O,-0Drive test

-overage Drive test

4uality Drive test


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Flow Chart of Network Optimization


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Course Contents


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Parameter djustment Principles

I!"N#IF$

PRO%&"'

MAKE

CHANGES

'ONI#OR

"FF"C#

'K"

C(N)"*

Parameter adjutme!t procedure


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5Parameter Types

"adio Parameter E!gi!eeri!g Parameter

Ha!dover

Parameter

Ha!dover

Parameter

Ha!dover

ParameterA!te!!a

Orie!tatio!

A!te!!a

#$tilt

A!te!!a

Heig%t


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&djustment of cell data parameters

&djust the cell parameters according to the features of actual

radio channel traffic and signaling load. he parameters are for

cell select"cell reselect"call setup" handover etc" so as to

improve the overall network performance and service $uality to

the end user.

&nother !asic principle of radio parameter adjustment is to

maximize the current network resource" traffic sharing in the the

whole network" increase the utilization of the e$uipment" so as to

increase the profit6investment ratio.


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&ccording to the feature of pro!lem to !e solved" there are

two types of radio parameter adjustment.

Solve static pro!lems7 &nalyze the average traffic and signaling

flows of the network and solve the network pro!lems thatexisted long time

Solve traffic overload and congestion pro!lems during some

special period caused !y special events.


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Course Contents


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!ri+in, #est #ools

)xample7 Drive test data


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*i,nalin, nal-zer

Signaling analyzer

%n real time" ,&6>9 signaling analyzer can trace &6!is interface

signaling message" &6/ interface signaling message" SS?

signaling message of %S3P" 3P and %#&P" and also !it error

rate of transmission system.

+or further analysis the signaling message files can !e saved

during online tracing" then they can !e opened for analysis at

anytime.


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*pectrum nal-zer

Spectrum analyzer

he spectrum analyzer is mainly used to test the characteristics

of fre$uency" including spectrum" power of the adjacent channel"

and fre$uency scanning etc.


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O'C #raffic *tatistics

Signalling test

instrument

BSC performance measurement functions

TCH

statistics

Drop

measure

Low HO suc

rate

HO

measurement

Incoming cell HO

Outgoing cell HO

List of alarmHigh block

rate

Rx! " Rxl measure

Har#ware Conk

out

balance between $L

" DL

List of alarmHigh #rop

rate

Drop call

measure

Rx! " Rxl

measure

List of alarm TCH

statistics

List of alarm


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Course Contents


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Common Problems of RN Optimization

he three most important performance criterias are coverage"

capacity $uality. they mainly correspond to the following

network pro!lems7

-overage -ongestion

%nterference

1andover

-1 call drop

Dual6!and network traffic distri!ution


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Common Problems ..Co+era,e

Coverage -overage hole

-overage hole may exist when coverage areas of two 2S

do not overlap or there are some !ig o!stacles in the

coverage area" this lead to no signal or very poor signallevel.

Over shooting

%n the actual network" the high 2S antenna can propagate

far away along a road and serve in area which it@s not

suppose to serve inA which result in the Bisolate %slandB

pro!lem.


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-heck and solve the coverage pro!lem7

Power control measurement +unction ( Statistics

Receiving Cevel ,easurement +unction ( Statistics

-ell ,easurement +unction ( Statistics %nter6cell 1andover ,easurement +unction ( Statistics


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-heck the coverage pro!lem7

-all Drop ,easurement +unction ( Statistics

Defined &djacent ,easurement +unction (Statistics

3ndefined &djacent ,easurement +unction ( Statistics Outgoing %nter -ell 1andover ,easurement +unction

( Statistics

Rx Cevel data ( Drive test


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-overage Pro!lem Solution7

&djust Radio parameters

&djust antenna parameters

3se !ooster" low loss com!iner and tower mount amplifier &dd new site (last resort


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Common Problems ..Capacit-

Capacity

-1 congestion

-heck -1 congestion rate7 attempted -1 seizers failure for all

(no radio resource availa!le on O,- traffic statistics data" or

compare the !usy hour traffic of each cell with the calculated

capacity in different /oS to judge the situation of traffic congestion . raffic !alance

&djust the antenna height" downtilt" and change the power of

2S and ,S.

&djust parameters for cell selection" cell reselection and handover

)na!le load handover and direct retry functions.


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Common Problems ..Interference

1ow to locate the interference

%nterference !and in -1 ,easurement +unction

( Statistics

Receiving Cevel ,easurement +unction ( Statistics

RxE4ual ( Drive test


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1ow to locate the interference

Ratio of handovers for uplink0downlink $uality ( Statistics

Receiving 4uality ,easurement (Statistics

-all drop measurement function ( Statistics oo many handover failure and reesta!lishment failures

( Statistics


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-heck and solve the interference pro!lems

-heck the place with interference and conversation $uality !y

drive test.

3se spectrum analyzer to find out the interference in the

fre$uency !and.

)na!le fre$uency hopping" D and power control functions.

-heck and eliminate e$uipment pro!lems (if any.


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,eans to decrease the interference 7

%ncrease the reuse distance !etween the co6fre$uency and

adjacent fre$uencies.

Decrease the transmitting power of 2S.

&djust the antenna height" azimuth" down6tilt.

3se the anti6interference technologies" such as fre$uency

hopping" power control" D" and so on.


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Common Problems ..(ando+er

-ommon handover pro!lems7

1andover failure and handover delay lead to !ad $uality or

call drop.

+re$uent handover decreases the conversation $uality and

increases system signaling load.

3nreasona!le proportion of outgoing inter6cell handover to

incoming inter6cell handover results in im!alanced traffic.


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-heck and solve handover pro!lems7

-heck the handover parameters (O,-

%nter6cell 1andover ,easurement +unction (Statistics

3ndefined &djacent -ell ,easurement +unction (Statistics

Outgoing %nter -ell 1andover ,easurement +unction (Statistics

%ncoming %nter -ell 1andover ,easurement +unction (Statistics

-1 ,easurement +unction (Statistics


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-auses of a!normal handover and solutions7

he outgoing inter cell handover threshold is too low.

he adjacent cells is congested.

here are undefined adjacent cells relationship.

he handover hysteresis and handover priority are not reasona!le.

he handover statistics times # and P are not set reasona!le.

%n 1-S network coexisting with other vendor@s cells" the external

cell@s parameters (such as C&-" -% and 2--1 must !e corrected.


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Common Problems /Call !rop

TCH call drop

During the /S, network operation" call drop is the main reason

the su!scri!ers complain. %t usually refers to the call dropped

after -1 channel seized or conversation connected" which can

!e located via traffic statistics or drive test.

here are many call drop causes. Such as poor signal strength"

interference and improper parameters.

here are two important counters related call drop" radio link

timeout (RC downlink and S&--1 multi6frame num!er

(uplink sent in system information. hese two counters should

!e set properly according to the traffic and coverage.


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Common Problems /!ual.band Network

Optimization for dual-and net!or"

ake the following special approaches when optimize the dual6

!and network" most of the approaches are same as single6!and

network optimization7

:hen /S, F99, network !elong to a same C&-

the features of two network are !asically same. Parameters such as

-RO can !e set flexi!ly according to the traffic" thus can !alance

the traffic and avoid cell congestion.

:hen /S, F99, network has there own locationarea code" -R1 and -RO should !e set properly to avoid fre$uent

location update.

&djust layer thresholds to !alance traffic !etween /S, F99


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Common Problems /!ual.band Network

#edicate mode

&dle mode Calli!g mode

Cell elect #irect retry

Ha!d over

Cell reelect

5Dual !and network optimization elements


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"0ercise

4uestions

Please write down 'P% for normal network

Please write down the work flow for radio network optimization

1ow to do for traffic !alance


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