12 GSM BSS Network KPI (TCH Assignment Success Rate) Optimization Manual2.doc

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GSM BSS Network KPI (TCH Assignment Success Rate)Otimi!ation Manua"

INT#RNA$

Product Name Confidentiality Level

G3BSC INT#RNA$

Product Version Total 25 pages

GSM BSS Network KPI (TCH Assignment Success Rate) Otimi!ation Manua"

(%or interna" use on"&)

Prepared y 'CMA GSM Network

Per*ormance Researc+ et,

Su S+i

!ate

2""#$"3$2%

&evie'ed y !ate yyyy$mm$dd

&evie'ed y !ate yyyy$mm$dd

Granted y !ate yyyy$mm$dd

Huawei Tec+no"ogies Co,- $t.,

A"" rig+ts reser/e.

Contents

0 e*inition o* TCH Assignment Success Rate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,1

0,0 Recommen.e. %ormu"a,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,1

0,2 Signa"ing Proce.ure an. Counters,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,1

2 %actors in Assignment Success Rate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,3




INT#RNA$

2,0 Har.ware %au"t,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,4

2,2 Transmission %au"t,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,4

2,5 Parameter Settings,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,4

2,6 TCH Congestion,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,7

2,1 Intra8network an. Inter8network Inter*erence,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,7

2,9 Co/erage Pro:"ems,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,0;

2,3 Antenna Pro:"ems,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,0;

2,4 Reeater Pro:"ems,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,0;

2,7 Mo:i"e P+one Pro:"ems,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,0;

5 Ana"&sis Proce.ure an. Otimi!ation Met+o. o* Assignment %ai"ures,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,00

5,0 Ana"&sis Proce.ure,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,00

5,2 Ana"&sis Proce.ure,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,05

6 Test Met+o.s,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,21

1 escrition o* Assignment Re<uests,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,21

9 Cases o* Otimi!ing Assignment Success Rate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,23

9,0 Hig+ Assignment %ai"ure Rate A*ter BTS Caacit& #=ansion,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,23

9,2 Hig+ Assignment %ai"ure Rate Because o* Imroer Parameter Settings,,,,,,,,,,,,,,,,,,,,,,,,,,24

9,5 ecrease in Assignment Success Rate .ue to Insu**icient C+anne" Resources,,,,,,,,,,,,,,,,,5;

9,6 $ow Assignment Success Rate Cause. :& Insu**icient Ater Resources,,,,,,,,,,,,,,,,,,,,,,,,,, ,,50

9,1 $ow Assignment Success Rate Because o* Con*iguration o* Ha"*8rate C+anne"s,,,,,,,,,,,,,52

3 %ee.:acks on Assignment Success Rate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,55




INT#RNA$

Re/ision Recor.

ate Re/ision

>ersion

C+ange escrition Aut+or

2""#$"3$3( ()" ra*t com"ete. Su S*i

2""#$"+$"+ ()" T+is .ocument is

mo.i*ie. accor.ing to t+e re/iew

comments,

Su S*i

Re*erences

Numer &eferences ,ut*or !ate

0 Gui.e to Tack"e G8Inter*erence

(2;;1;5008A80,;)

C+en Bao"in 2;;18;5800

2 Gui.e to Tack"e 'ire"ess

Co/erage Pro:"ems82;;1;2248

A85,;

Co/erage

Tack"e Team

2;;18;2824

5 GSM BSS Network KPI (TCH

Assignment Success Rate)

Base"ine

'u ?+en 2;;38;185;




INT#RNA$

( !efinition of TC/ ,ssignment Success &ate

T+e TCH assignment success rate re*ers to t+e rate t+at t+e TCHs assigne. :& t+e

BSC are success*u""& sei!e., Success*u" TCH assignment in.icates t+e roce.ure

*rom t+e BSC recei/ing t+e C+anne" Re<uest message sent :& t+e MSC to recei/ing

t+e Assignment Com"ete message, TCH Assignment Success Rate is one o*

accessi:i"it& KPIs, It in.icates t+e rate o* t+e MSs success*u""& sei!ing t+e TCHs to

make ca""s, T+is KPI .irect"& a**ects t+e user e=erience,

Recommen.e. %ormu"a

T+e TCH assignment success rate is o:taine. t+roug+ t+e tra**ic statistics, T+e

recommen.e. *ormu"a is as *o""ows@ TCH Assignment Success Rate (Com"ete.

TCH AssignmentsTCH Assignment Re<uests) = 0;;

%or .etai"e. *ormu"a- re*er to t+e GSM BSS Network KPI (TCH Assignment Success

Rate) Baseline,

Signa"ing Proce.ure an. Counters

Common assignment roce.ure




INT#RNA$

Inter8BSC .irecte. retr& roce.ure

Note@ T+e measurement oints in t+e re/ious *igure in.icate t+e *o""owing,

ADDAssignment Re<uests (Sei!ure Re<uests)

BDDCom"ete. Assignments (Success*u" Sei!ures)

CDDSuccess*u" Inter8BSC irecte. Retries

T+e measurement oints in t+e rece.ing *igures s+ow t+at t+e assignment

success rate o* t+e BSC52BSC9;;; inc"u.es t+e assignment re<uests (sei!ure

re<uests) an. com"ete. assignments (success*u" sei!ures),

TakeInter8BSC irecte. Retr& as an e=am"e, In t+e Inter8BSC irecte. Retr&

roce.ure- t+e BSC increases t+e /a"ue o* t+e success*u" assignment in t+e originating

ce""- on recei/ing t+e C"ear CM message *rom t+e MSC, In t+e Intra8BSC irecte.

Retr& roce.ure- t+e BSC increases t+e /a"ue o* t+e success*u" assignment in t+e

originating ce""- on recei/ing t+e C"ear CM message *rom t+e MSC, I* t+e .irecte.

retr& *ai"s- t+e BSC .ecreases t+e /a"ue o* t+e success*u" assignment in t+e originating

ce"", In t+e irecte. Retr& roce.ure- t+e counters re"ate. to +an.o/er are a"so

measure.,

T+e *o""owing *igure s+ows t+e rocessing work*"ow a*ter t+e BSC recei/es t+e

c+anne" re<uest message an. t+e measurement oints o* success*u" TCH sei!ures,




INT#RNA$

Processing roce.ure a*ter t+e BSC recei/es t+e CHAN R#E message

2 actors in ,ssignment Success &ate

Accor.ing to t+e user com"aint cases an. network otimi!ation e=erience- t+e

maFor *actors t+at in*"uence t+e TCH assignment success rate are summari!e. as

*o""ows@

0, Har.ware *au"t 2, Transmission *au"t 5, Parameter settings 6, TCH

congestion 1, Intra8network or inter8network inter*erence9, Co/erage ro:"ems 3,

Antenna ro:"ems 4, Reeater ro:"ems 7, Mo:i"e +one ro:"ems,




INT#RNA$

Har.ware %au"t

'+en a TR or a com:iner is *au"t&- some o* t+e TCHs :ecome una/ai"a:"e *or

use, T+ere*ore- TCH assignment success rate .ecreases,

Transmission %au"t

Ba. transmission <ua"it& on t+e A inter*ace or A:is inter*ace .ue to /arious

reasons an. unsta:"e transmission "inks a"so cause TCH assignment *ai"ures,

Parameter Settings

T+e settings o* some arameters o* BSC an. MSC a"so a**ect TCH assignment

success rate, T+e main arameters inc"u.e@

() !irected &etry ,llo'ed an. ,llo' &eassign are set to No, T+ere*ore- t+e

TCH reassignment an. .irecte. retr& *unctions are not ena:"e.,

2) Speec* Version .oes not suort +a"*8rate an. AMR +a"*8rate)

3) '+en t+e BSC ena:"es +a"*8rate or AMR +a"*8rate- t+e arameters on t+e MSC

si.e are not con*igure. consistent"&,

6) TC/ Traffic Busy T*res*old 7percentage8 is set too great,

5) ,ssignment Cell Load 9udge :nale is set to No,

+) T+e *unctions suc+ as <ueuing an. reemtion are not ena:"e. on t+e MSC

si.e,

;) T+e ower "e/e" .i**erence :etween t+e BCCH an. t+e TCH is great,

#) S!CC/ !ynamic ,llocation ,llo'ed is set to <es- an. imme.iate

assignment re<uests are great,

%) T3("; (Timer *or t+e ASS CMP message) is set too s+ort,

(") T3("3, (Timer *or t+e HO CMP message) is set too "ong,

(() Level of Preempting !ynamic C*annel is set to !ynamic c*annels

carrying services cannot e preempted) T+ere*ore- t+e riorit& o* t+e PS

ser/ices is +ig+er,




INT#RNA$

TCH Congestion

'+en t+e TCH congestion occurs- new access re<uests are reFecte. .ue to t+e

una/ai"a:i"it& o* t+e TCH, T+us- t+e TCH assignment success rate is a**ecte.,

T+e ossi:"e causes are@

0, Ha"*8rate an. AMR +a"*8rate are not con*igure. *or :etter seec+ <ua"it&,

2, Hig+ tra**ic /o"ume cause. :& .ense su:scri:er .istri:ution in t+e ce"" or

cross8co/erage

Burst tra**ic increases :ecause t+e neig+:oring BTS is out o* ser/ice or ot+er :urst

e/ents occur,

5, T+e ce"" is con*igure. wit+ too muc+ static PCHs or .&namic PCHs- an.

t+e PS ser/ices +a/e +ig+er riorit& o/er CS ser/ices,

6, Some TRs in t+e ce"" are *au"t& or t+e TRs are manua""& :"ocke.,

1, /er& ear"& assignment is ena:"e.,

Intra8network an. Inter8network Inter*erence

I* inter8network inter*erence or reeater inter*erence occurs- or i* se/ere intra8

network inter*erence occurs :ecause o* tig+t *re<uenc& reuse- t+e MS ma& *ai" to

.eco.e t+e assigne. TCH roer"&, T+us- t+e TCH sei!ure *ai"ure occurs, T+is a**ects

t+e TCH assignment success rate,

T+e *o""owing t&es o* inter*erence ma& occur@

0, Inter*erence *rom inter8network scram:"ers or ri/ate"& insta""e. antennas

2, Inter*erence *rom nicom CMA network

5, Inter*erence *rom t+e reeater

6, Inter*erence *rom intermo.u"ation

1, Co8c+anne" inter*erence or a.Facent8c+anne" inter*erence




INT#RNA$

Co/erage Pro:"ems

ue to t+e "ow co/erage "e/e" cause. :& t+e oor co/erage- t+e MS ma& *ai" to

.eco.e t+e assigne. TCH roer"&, T+us- t+e TCH sei!ure *ai"ure occurs, T+is

a**ects t+e TCH assignment success rate,

Antenna Pro:"ems

%or t+e .ou:"e transmit antennas- inconsistent a!imut+ an. ti"t cause. :& imroer

insta""ation o* t+e two antennas ma& cause .i**erent co/erage o* t+e BCCH TR an.

t+e TCH, T+us- t+e assignment *ai"ure occurs,

T+e in/erse connection o* t+e antennas a"so causes t+e imroer signa" co/erage,T+ere*ore- t+e MS cannot easi"& sei!e t+e TCH an. t+e assignment *ai"ure occurs,

Reeater Pro:"ems

T+e :an. se"ecti/e reeater magni*ies t+e signa"s carrie. on t+e BCCH *re<uenc&

t+ere*ore- t+e co/erage ranges o* t+e BCCH an. t+e TCH are inconsistent, T+us- t+e

MSs on t+e e.ge o* t+e ce"" can recei/e BCCH signa"s :ut *ai" to sei!e t+e TCH,

Mo:i"e P+one Pro:"ems

Some MSs o* ear"& mo.e"s .o not suort +a"*8rate seec+ /ersion 0, T+ere*ore-

w+en t+e BSC assigns t+e +a"*8rate c+anne" to t+e MS- t+e MS *ai"s to sei!e t+e

c+anne" an. returns t+e ASSIGNM#TN %AI$R# message, T+e cause o* t+e *ai"ure

is c+anne" mo.e unacceta:"e, T+ere*ore- assignment *ai"ure occurs,




INT#RNA$

3 ,nalysis Procedure and =ptimiation 4et*od of ,ssignment ailures

Ana"&sis Proce.ure




INT#RNA$




INT#RNA$

Cause BSC Level Cell$Level T&@$Level

/ard'are

ailure

BSC Measurement8

Assignments

Measurement er

BSC8

%ai"e. Assignments

er BSC

(#<uiment

%ai"ure)

%ai"e. Assignments

er BSC (In/a"i.

State)

Call 4easurement $AC+anne" Acti/ation

Measurement er Ce""$A

CHAN ACTI> NACK

Messages Sent :& BTS in

Assignment Proce.ure

C+anne" Acti/ation

Timeouts in Assignment

Proce.ure

-P1 4easurement$A

TR A/ai"a:i"it&

TCH A/ai"a:i"it&

3) C*ec? t*e transmission in t*e cells 'it* *ig* assignment failure rate

Poor transmission <ua"it&- unsta:"e transmission "inks- or insu**icient

resources on t+e A:is inter*ace an. A inter*ace ma& "ea. to TCH assignment

*ai"ure, Lou can c+eck t+e transmission status :& c+ecking t+e a"arms

re"ate. to transmission, I* a "arge num:er o* transmission a"arms are

generate.- &ou can in*er t+at transmission *ai"ures occur, T+en- &ou s+ou".

c+eck t+e transmission connections, JRe"e/ant Cases

In a..ition- &ou can c+eck t+e tra**ic statistics re"ate. to transmission

*ai"ures- as s+own in t+e *o""owing ta:"e,

Cause BSC Level Cell$Level T&@$

Level

Transmi BSC

Call 4easurement $

A,ssignment 4easurement$A

Non

e)




INT#RNA$

ssion

failure

4easurement$

AAssignments

Measurement er

BSC$A

%ai"e. Assignments

er BSC (Terrestria"

Circuit A"rea.&

A""ocate.)

%ai"e. Assignments

er BSC

(Re<ueste.

Terrestria" Resource

na/ai"a:"e)

&esource

4easurement

Num:er o* Assignment %ai"ures

(No A:is Resource A/ai"a:"e)

BSC 4easurement$A L,P!

4easurement

6) C*ec? t*e parameter settings of t*e cells 'it* *ig* TC/ assignment

failure rate

Settings o* t+e arameters on t+e BSC an. MSC a"so a**ect t+e TCH

assignment success rate, Lou s+ou". c+eck t+e arameter settings o* t+e

*au"t& ce"" *rom t+e *o""owing asects@

0) C+eck w+et+er !irected &etry ,llo'ed an. ,llo' &eassign are set

to <es,

T+e settings o* !irected &etry an. ,llo' &eassign +a/e great

imact on t+e assignment success rate, I* t+e signa"ing "oa. o* t+e

current network is not +ea/&- Huawei recommen.s t+at ena:"e t+ese

two *unctions to increase t+e assignment success rate,

2) C+eck w+et+er Speec* Version is set to suort +a"*8rate CS80 an.

+a"*8rate CS85,




INT#RNA$

I* +a"*8rate an. AMR +a"*8rate are a""owe. at t+e site- Huawei

recommen.s t+at ena:"e t+em to increase t+e assignment success rate,

5) A*ter t+e BSC ena:"es +a"*8rate or AMR +a"*8rate- c+eck w+et+er t+e

arameters on t+e MSC si.e are con*igure. consistent"&,

I* t+e& are not set on t+e BSC si.e- a.Fust t+e .ata con*iguration on

t+e MSC to :e consistent wit+ t+at on t+e BSC,

6) C+eck w+et+er TC/ Traffic Busy T*res*old 7percentage8 is set too

+ig+ in t+e con.ition o* suorting +a"*8rate,

I* TC/ Traffic Busy T*res*old 7>8 is set o/er 4;- t+e *u""8rate is

+ar. to c+ange into +a"*8rate, I* TC/ Traffic Busy T*res*old 7>8

is set too "ow- more +a"*8rate c+anne"s can :e use.,

1) C+eck w+et+er ,ssignment Cell Load 9udge :nale is ena:"e.,

#na:"e t+e irecte. Retr& *unction, I* t+e ce"" suorts .irecte.

retr& an. t+e "oa. o* t+e ce"" is e<ua" to t+at .e*ine. :& t+e .irecte.

retr& t+res+o".- t+en rocee. wit+ t+e .irecte. retr& roce.ure, T+is

a/oi.s t+e MSC sen.ing TCH re<uests w+en t+e ce"" is congeste.-

an. t+us .ecreases assignment *ai"ures cause. :& congestion,

9) C+eck w+et+er t+e <ueuing an. reemtion *unctions are ena:"e. on

t+e MSC si.e,

T+ese two *unctions s+ou". :e ena:"e. on t+e MSC si.e to imro/e

TCH assignment success rate,

C+eck w+et+er t+e ower "e/e" .i**erence :etween t+e BCCH TR

an. t+e non8BCCH TR is great, I* t+e .i**erence is +ig+er t+an two

stes- t+e .own"ink recei/es "e/e" .i**erence :etween t+e BCCH an.

t+e TCH is great, T+us- t+e TCH sei!ures o* MSs on t+e e.ge o* t+e

ce"" are .i**icu"t, T+ere*ore- t+e static ower "e/e" .i**erence :etween

t+e BCCH TR an. non8BCCH TR s+ou". not :e o/er two stes,

3) C+eck w+et+er S!CC/ !ynamic ,llocation ,llo'ed is set to <es,

I* it is set to <es an. t+ere are man& imme.iate assignment re<uests




INT#RNA$

(suc+ as "ocation u.ating) in t+e ce""- t+e congestion ma& occur an.

t+us t+e assignment success rate .ecreases, I* t+e SCCH tra**ic

/o"ume is too +ig+- t+e caacit& o* t+e ce"" s+ou". :e e=an.e.,

4) C+eck w+et+er T3"(; (ms) (Timer *or t+e ASS CMP message) is set

too sma"",

I* it is set too "ow- t+e timer ma& e=ire :e*ore t+e assignment is

com"ete.- t+us "ea.ing to assignment *ai"ures, Setting t+e timer to a

greater /a"ue can imro/e t+e assignment success rate,

7) C+eck w+et+er T3("3, (ms) (Timer *or t+e HO CMP message) is set

too great,

I* it is set too great- t+e TCH resources ma& :e waste.- t+us "ea.ing

to assignment *ai"ures, Setting t+e timer to a sma"" /a"ue can imro/e

t+e assignment success rate,

0;) C+eck w+et+er Level of Preempting !ynamic C*annel is set to

!ynamic c*annels carrying services cannot e preempted,

I* t+e PS ser/ices +a/e +ig+er riorit& o/er t+e CS ser/ices an. t+at

t+e PS *"ow is +ig+- t+e .&namic PCHs are sei!e. :& PS ser/ices

an. t+e TCHs are insu**icient, T+is arameter s+ou". :e set to

Control c*annels cannot e preempted,

Euer& t+e re"ate. tra**ic statistics to see w+et+er t+e .ata

con*iguration is imroer, T+e re"ate. tra**ic statistics are s+own in

t+e *o""owing ta:"e,

Cause BSC$

Level

Cell$Level T&@$Level

1mproper

Parameter

Setting

None) C*annel 4easurement $

AC*annel Conversion

4easurement per Cell$A

C+anne" Assignment Re<uests

TR Attri:utes8

C+anne" Attri:utes

C+anne" T&e




INT#RNA$

(TCHH)

Num:er o* PC8Initiate.

Re<uests *or &namic PCH

Num:er o* C+anne"

Con/ersions (TCH8SCCH)

Success*u" C+anne"

Con/ersions (TCHH8TCH%)

C*annel 4easurement $

AC*annel ,ssignment ueue

4easurement per Cell$A

ueuing &euests

5) ,nalye t*e congestion in t*e cells 'it* *ig* assignment failure rate

,TCH Congestion Rate %ai"e. TCH Sei!ures .ue to Bus& TCH

(Signa"ing C+anne") %ai"e. TCH Sei!ures .ue to Bus& TCH (Tra**ic

C+anne") %ai"e. TCH Sei!ures in TCH Han.o/ers .ue to Bus& TCH (Tra**ic

C+anne")TCH Sei!ure Re<uests (Signa"ing C+anne") TCH Sei!ure Re<uests

(Tra**ic C+anne") TCH Sei!ure Re<uests in TCH Han.o/ers (Tra**ic C+anne")

%or .etai"s on t+e comuting met+o.- re*er to t+e GSM BSS Network KPI

(TCH Assignment Success Rate) Baseline,

I* t+e congestion rate o* t+e *au"t& ce"" is +ig+ (o/er 0;)- t+e *ai"e.

assignment is main"& cause. :& congestion, T+en- c+eck t+e causes o* TCH

congestion *rom t+e *o""owing asects,

JRe"e/ant Cases

0) C+eck w+et+er t+e ce"" suorts +a"*8rate CS80 an. +a"*8rate CS85

*rom t+e arameter con*iguration, I* t+e seec+ <ua"it& meets t+e

.eman.- &ou can ena:"e +a"*8rate an. AMR +a"*8rate,

2) C+eck w+et+er cross co/erage or un:a"ance. .istri:ution o* tra**ic

e=ists in t+e ce"" :& .ri/e tests, I* t+e *au"ts e=ist- .ecrease t+e




INT#RNA$

co/erage range o* t+e ce"" :& re.ucing t+e ower- "owering t+e

antenna ti"t- or increasing 4in ,ccess Level,

5) Euer& t+e a"arm "ogs to see w+et+er t+e surroun.ing ce""s are out o*

ser/ice- an. w+et+er an emergenc& suc+ as an assem:"& occurs, T+e

congestion cause. :& t+ese reasons can :e +an."e. "ater,

6) C+eck w+et+er t+e ce"" is con*igure. wit+ too muc+ static PCHs or

.&namic PCHs *rom t+e c+anne" con*iguration (PS ser/ices *irst), I*

t+e PS ser/ice /o"ume is re"ati/e"& sma""- re.uce t+e num:er o*

PCHs roer"&,

1) C+eck w+et+er t+e /er& ear"& assignment *unction is ena:"e., I* it is-

.isa:"e t+e *unction or e=an. t+e caacit&,

9) C+eck w+et+er TC/ ,vailaility is 0;; *rom t+e tra**ic statistics, I*

it is not 0;;- t+e TRs ma& :e *au"t& or some c+anne"s ma& :e

manua""& :"ocke. or susen.e., In t+is case- c+eck t+e status o* TR

an. c+anne" an. restore t+em in time,

T+e re"e/ant counters are .escri:e. in t+e *o""owing ta:"e,

Cause

s

BSC$Level Cell$Level T&@$

Level

Conge

stion

BSC

Measurement8

Assignment

Measurement er BSC8

%ai"e. Assignments

er BSC (C+anne"

na/ai"a:"e)

BSC

Measurement(BSC)$

AAccess Measurement

$DE$

Ca"" Measurement8KPI

Measurement8TCH Congestion

Rate (o/er*"ow)

TCH A/ai"a:i"it&%ai"e. TCH

Sei!ures .ue to Bus& TCH (Tra**ic

C+anne") TCH Sei!ure

Re<uests (Tra**ic C+anne")

Call 4easurement $

A,ssignment 4easurement$A

%ai"e. Assignments (C+anne"

Non

e)




INT#RNA$

er BSC$A TCH

Congestion Rate er

BSC

na/ai"a:"e)

+) ,nalye t*e interference in t*e cells 'it* *ig* assignment failure

rate

'+en serious intra8network inter*erence an. inter8network inter*erence

occur- t+e MS ma& not sei!e t+e assigne. TCH success*u""&, T+ere*ore-

assignment *ai"ures occur, Lou can o:tain t+e in*ormation on $ inter*erence

:& c+ecking t+e .istri:ution status o* t+e inter*erence :an.s, T+e +ig+er

ercentage o* :an.s 581 in.icates t+at serious $ inter*erence e=ists, Lou can

o:tain t+e in*ormation on $ :& .ri/e test or c+ecking t+e *re<uenc&

con*iguration on NASTAR, T+e inter*erence is c"assi*ie. into inter8

network inter*erence an. intra8network inter*erence, %or t+e .etai"e. met+o.

o* e"iminating t+e inter*erence- re*er to t+e Guie to Tackle G!Inter"erence

(#$$%$&''!A!'$),

T+e re"e/ant counters are "iste. in t+e *o""owing ta:"e,

Cause

s

BSC$Level Cell$Level T&@$Level

1nterf

erence

BSC

Measurement8

Han.o/er Attemt

Measurement er

BSC8 Attemte.

Han.o/ers er BSC

"ink Signa"

Eua"it&)

Attemte. Han.o/ers

Ca"" Measurement8

Outgoing Interna" Inter8

Ce"" Han.o/er

Measurement er Ce""8


Ce"" Han.o/er Re<uests

er Ce"" (Signa" Eua"it&)8


MR Measurement8

Ana"&!e. Measurement

o* Inter*erence Ban. er

TR8

Mean Num:er o*

TCHs in Inter*erence

Ban. 0

Mean Num:er o* TCHs

in Inter*erence Ban. 2




INT#RNA$

er BSC

own"ink Signa"

Eua"it&)

Attemte. Han.o/ers

er BSC

(Ot+er Causes)

Ce"" Han.o/er Re<uests

er Ce"" (Ot+er Causes)

Mean Num:er o* TCHs


Mean Num:er o* TCHs


Mean Num:er o* TCHs


;) C*ec? t*e coverage in t*e cells 'it* *ig* assignment failure rate

To c+eck t+e co/erage status- <uer& t+e signa" "e/e" .istri:ution, I* t+e $

"e/e"s o* a "arge num:er o* MRs are "ower t+an 71 .Bm- t+e co/erage o*

t+e ce"" is re"ati/e"& oor,

I* t+e co/erage o* t+e ce"" is oor :ut t+e congestion .oes not occur- so"/e

t+e co/erage ro:"ems :& a.Fusting t+e .own ti"t o* t+e antenna- increasing

t+e transmit ower- a..ing reeaters- or c+anging t+e com:ination mo.e,

In a..ition- <uer& t+e tra**ic statistics to "ocate t+e co/erage ro:"ems,


Causes

BSC$Level Cell$Level T&@$Level

Cov

erag

e

BSC

Measurement8

Han.o/er Attemt

Measurement er BSC8

Attemte.

Han.o/ers er BSC

("ink Signa"

Strengt+)

Attemte. Han.o/ers

er BSC

(own"ink Signa"

Ca"" Measurement8 Outgoing

Interna" Inter8Ce"" Han.o/er

Measurement er Ce""8Outgoing

Interna" Inter8Ce"" Han.o/er

Re<uests (Signa" Strengt+)

Ca"" Measurement8Outgoing

#=terna" Inter8Ce"" Han.o/er

Measurement er Ce""8Outgoing

MR Measurement8

TCH% Recei/e

$e/e" Measurement

4& 4easurement$

ATC// &eceive

Level 4easurement




INT#RNA$

Strengt+) #=terna" Inter8Ce"" Han.o/er

Re<uests("ink Signa" Strengt+)

Outgoing #=terna" Inter8Ce""

Han.o/er Re<uests(own"ink

Signa" Strengt+)

%or .etai"e. met+o. o* so"/ing co/erage ro:"ems- re*er to t+e GSM BSS

Network Per"ormance KPI (Coerage) *+timi,ation Manual ,

#) C*ec? t*e antenna in t*e cells 'it* *ig* assignment failure rate

%or .ou:"e transmit antennas- c+eck w+et+er t+e ti"t an. t+e a!imut+

o* t+e antennas are consistent, I* t+e& are inconsistent- a.Fust t+em to :e

consistent,

In a..ition- ana"&!e t+e .ata o* t+e .ri/e test to see w+et+er t+e antenna

Fumers are re/erse"& connecte., I* t+e& are- connect t+e Fumers correct"&,

I* t+e antenna s&stem (antenna an. *ee.er) is *au"t&- t+e co/erage range

o* t+e ce"" :ecomes sma""er- t+us "ea.ing to *ai"e. TCH sei!ures, I* t+e *au"ts

are *oun.- c+ange t+e antenna or *ee.er,

T+e *au"t on antenna s&stem is genera""& s+own in t+e *o""owing wa&s@

T+e .ro rate an. +an.o/er *ai"ure rate o* t+e ce"" are re"ati/e"& +ig+ t+e

.i**erence :etween t+e $ <ua"it& an. t+e $ <ua"it& is great :ot+ t+e $

<ua"it& an. t+e $ <ua"it& are oor, Lou can <uer& t+e re"e/ant counters as

"iste. in t+e *o""owing ta:"e to see w+et+er t+e *au"t on antenna s&stem e=ists,

Causes BSC$

Level


,ntenna None) Ca"" Measurement8 Ca"" ro

Measurement8Ca"" ro Rate on

TCH% er ce""

Ca"" ro Rate on TCHH er ce""

MR Measurement8

Recei/e Eua"it&

Measurement er TR

MR Measurement8




INT#RNA$

Call 4easurement $A-P1

4easurement$A

Ca"" ro Rate on TCH er ce""

(#=c"u.ing Han.o/er)

Tra**ic Ca"" ro Ratio er ce""

Success Rate o* Ra.io Han.o/er

"ink8an.8own"ink

Ba"ance Measurement er

TR

%) C*ec? '*et*er t*e cell 'it* *ig* assignment rate is configured 'it*

t+e :an. se"ecti/e reeater,

C+eck w+et+er !irectly 4agnifier Site lag on t+e $MT is set to <es)

I* it is set to <es0 a reeater is con*igure. in t+e ce"") I* it is set to No0 c+eck

w+et+er ot+er te"ecom oerators mount t+e reeaters aroun. t+e ce"",

I* t+ere is a reeater mounte. aroun.- c+eck w+et+er t+e reeater is t+e

:an. se"ecti/e reeater correson.ing to t+e BCCH *re<uenc& :an., I* it is-

c+eck w+et+er t+e $$ magni*&ing coe**icient is e=cessi/e"& +ig+, I* it is-

re.uce t+e coe**icient, I* t+e imact is serious- .isa:"e t+e :an. se"ecti/e

reeater,

In a..ition- c+eck w+et+er t+e .i**erence :etween t+e TA .istri:ution o*

t+e BCCH TR an. non8BCCH TR is great in t+e ce"" wit+ +ig+

assignment *ai"ure rate, I* t+e BCCH TR wit+ great TA reorts certain

num:ers o* MRs w+i"e t+e non8BCCH TR .oes not- t+e BCCH *re<uenc&

:an. ma& :e con*igure. wit+ t+e :an. se"ecti/e reeater, T+is ma& cause

inconsistent co/erage :etween t+e BCCH TR an. non8BCCH TR- w+ic+

"ea.s to man& assignment *ai"ures,

Causes BSC$Level Cell$

Level

T&@$Level

BCC/

reuency

Band

None)

None) 4& 4easurement$A Num:er o*

MRs Base. on

TA er TR




INT#RNA$

Configured

'it* Ban.

Se"ecti/e

Reeater

(") C*ec? '*et*er a large numer of 4Ss do not support *alf$rate

c*annel in t*e cell 'it* *ig* assignment failure rate)

C+eck w+et+er man& su:scri:ers use o".8mo.e" mo:i"e +ones t+at .o not

suort t+e +a"*8rate c+anne", I* t+ere are man& suc+ mo:i"e +ones- +a"*8

rate an. *u""8rate .&namic con/ersion s+ou". :e ena:"e. to e=an. t+e

caacit&,JRe"e/ant Cases

In a..ition- c+eck t+e re"ate. counters to see w+et+er t+e ro:"ems e=ist,


Causes BSC$

Level


T*e 4S does

not support

*alf$rate

c*annel)

None

) C*annel 4easurement$AC+anne"

Assignment Re<uest Measurement er

Ce""$AC+anne" Assignment Re<uests

(TCCH)

Success*u" C+anne" Assignments

(TCCH)

None)

4 Test 4et*ods

TCH assignment success rate is one o* tra**ic measurement counters- w+ic+ can




INT#RNA$

:e o:taine. t+roug+ registration or reorting o* t+e re"ate. tra**ic measurement

counters, Genera""&- t+is counter is not measure. t+roug+ .ri/e tests, ri/e tests

cannot in.icate t+e actua" assignment success rate :ecause o* t+e "imite. sam"es an.

incom"ete test routes,

Current"&- manu*acturers an. oerators use .i**erent *ormu"as *or ca"cu"ating TCH

assignment success rate- t+us "ea.ing to .i**erent /a"ues o* t+is counter, In actua"

measurement- &ou s+ou". register t+e seci*ic counters an. use an aroriate

*ormu"a to ca"cu"ate t+e /a"ue o* t+e counter,

5 !escription of ,ssignment &euests

Trace t+e RS$ messages on t+e A:is inter*ace, Lou can <uer& t+e signa"ing tracing

*i"e on t+e $MT or :& using t+e Signal ,nalye Tool)- %i"ter t+e signa"ing to *in.

!ata &euest inc"u.ing t+e CHAN R#E message- as s+own in t+e *o""owing *igure,




INT#RNA$

T+e meaning o* eac+ message is as *o""ows@

C+anne" T&e@ C+anne" T&e in.icates t+e t&e o* t+e re<ueste. c+anne",

Genera""&- t+e TCH is re<ueste., It is reresente. :& t+e *irst *i/e :its o* :&te 02,

TN in.icates t+e num:er o* t+e times"ot o* t+e re<ueste. c+anne", It is reresente.

:& t+e "ast t+ree :its o* :&te 02,TSC stan.s *or training se<uence co.e, It is reresente. :& t+e *irst t+ree :its o*

:&te 05,

Hoing %"ag in.icates w+et+er t+e ce"" is ena:"e. wit+ *re<uenc& +oing, It is

reresente. :& :it 6 o* :&te 05,




INT#RNA$

6, 'rong connections o* R% ca:"es

0, Troules*ooting. $ock t+e *re<uenc& an. con.uct a .ia"ing

test, T+e resu"t s+ows t+at t+e sei!ure o* TRs ; to 6 is norma",

Manua""& :"ock TRs 0 to 5 e=cet t+e main BCCH, Con.uct

t+e .ia"ing test again wit+ t+e *re<uenc& "ocke. an. *in. t+at t+e

recei/e "e/e" .ecreases to 0;2 .Bm .uring TCH assignment,

T+e assignment *ai"s,

2, #=c+ange t+e new"& e=an.e. TR wit+ anot+er TR an.

er*orm t+e test, T+e *au"t ersists,

5, Re"ace t+e R% ca:"es an. t+e *au"t ersists,

6, Because *au"ts occur on t+e TRs 02 to 01- t+e SC ma& :e

*au"t&, uring t+e re"acement o* t+e SC- t+e R% ca:"es are

*oun. to :e incorrect"& connecte. to t+e TQCOM o* C, T+e

TRs 0201 .o not transmit R% signa"s, Connect t+e R% ca:"es

to t+e TQP ort an. t+en er*orm a .ia"ing test, A""

times"ots are norma""& sei!e.,

Summary. #nsure correct ca:"e connections w+en using SC an. C

.uring caacit& e=ansion o* a BTS, 'rong connections o* ca:"es

can cause assignment *ai"ure,

9,2 Hig+ Assignment %ai"ure Rate Because o* Imroer Parameter Settings

FProlem !escription

An o**ice uses t+e e<uiment o* Huawei an. manu*acturer S, T+e statistics

s+ow t+at t+e TCH success rate cannot reac+ 74- t+e otima" /a"ue *or t+e

o**ice, T+e Huawei e<uiment .oes not outer*orm t+e e<uiment *rom

manu*acturer S, T+e TCH assignment success rate o* Huawei e<uiment is

"ower t+an t+e a/erage /a"ue o* t+e w+o"e network,

FProlem ,nalysis and Solution

Cause ,nalysis.




INT#RNA$

TCH Sei!ure Re<uests in.icates t+e num:er o* ASSIGNM#NT R#E#ST

messages t+at t+e BSC recei/es *rom t+e MSC in t+e assignment roce.ure,

Success*u" TCH Sei!ures is measure. in t+e *o""owing cases@

0, '+en t+e BSC recei/es a CHANN#$ ACTI>ATION ACKNO'$#G#

message *rom t+e BTS in t+e roce.ure o* /er& ear"& assignment- t+is counter

is incremente. :& one,

2, In t+e assignment roce.ure- i* t+e .irecte. retr& roce.ure wit+ t+e target

ce"" un.er anot+er BSC is success*u"- t+e MSC sen.s a C$#AR COMMAN

message to t+e originating ce"" to c"ear t+e origina" connection, '+en t+e

originating BSC recei/es t+e C$#AR COMMAN message- t+is counter is

incremente. :& one,

5, In t+e assignment roce.ure- i* t+e .irecte. retr& roce.ure wit+ t+e target

ce"" un.er anot+er BSC is success*u"- t+e target ce"" sen.s an Inter C"ear

Re<uest message to t+e originating ce"" to in*orm t+e originating ce"" to c"ear

t+e resources an. connection, '+en t+e originating BSC recei/es t+e message-

Success*u" TCH Sei!ures is measure.,

6, T+e /a"ue o* t+is counter e=c"u.es t+e num:er o* ASSIGNM#NT

COMP$#T# messages t+at t+e BSC sen.s to t+e MSC a*ter t+e .irecte. retr&

roce.ure is er*orme. success*u""& in t+e target ce"" wit+in t+e BSC,

T+e ana"&sis o* t+e assignment roce.ure s+ows t+at TCH sei!ure *ai"ure is

main"& cause. :& c+anne" una/ai"a:i"it& .ue to congestion an. no receit o*

t+e CHANN#$ ACTI>ATION ACKNO'$#G# message *rom t+e BTS, In

a..ition- t+e .irecte. retr& roce.ure +as great imact on success*u" TCH

sei!ure, T+e ana"&sis o* arameters in.icates t+at t+e current network .oes not

ena:"e t+e *unctions o* .irecte. retr& an. reassignment, In t+is case- .irecte.

retr& can :e ena:"e. to reassign a TCH to increase t+e TCH assignment

success rate (e=c"u.ing +an.o/er),

Troules*ooting.

#na:"e .irecte. retr& in t+e BSC wit+ "ow TCH assignment success rate an.

comare t+e tra**ic statistics o* t+e same time o* two .a&s, T+e resu"t s+ows t+at t+e

TCH sei!ure success rate increases :& a:out 2- *rom 79,0 to 74 ,Per*orm t+e

same roce.ure in t+e ot+er two BSCs in t+e network, T+e TCH sei!ure success rate




INT#RNA$

o* t+e entire network increases *rom 79,1 to 74,2, T+en- a.Fust ,llo' &eassign to

<es) T+e TCH sei!ure success rate o* t+e network increases to 74,6, T+is /a"ue

e=cee.s t+at o* t+e e<uiment *rom manu*acturer S an. reac+es t+e .eman. o* t+e

o**ice, T+us- t+e user satis*action is imro/e.,

Summary@ A.Fusting !irected &etry an. ,llo' &eassign to <es can increase TCH

sei!ure success rate,

9,5 ecrease in Assignment Success Rate .ue to Insu**icient C+anne"

Resources

FProlem !escription

T+e o**ice in Pakistan reorts t+at t+e assignment success rate on site is too"ow,


Cause ,nalysis.

B& ana"&!ing t+e tra**ic statistics :e*ore t+e atc+ "oa.ing- t+e engineers

in t+e +ea.<uarters t+ink t+at t+e "ow assignment success rate is not cause. :&

t+e s"ow re"ease o* t+e A inter*ace circuits :ut t+e insu**icient TCH%

resources on t+e BSC,

T+e main reasons are =t*er Causes- C*annel Hnavailale- an.

Terrestrial Circuit ,lready ,llocated, T+e engineers in t+e +ea.<uarters

t+ink t+at =t*er Causes an. C*annel Hnavailale in.icate t+at t+e TCH%

resources are insu**icient, Terrestrial Circuit ,lready ,llocated in.icates

t+at re"ease .e"a& o* t+e circuit e=ists +owe/er- t+is is not t+e main reason

t+at causes assignment *ai"ure on site,

Troules*ooting.

Suggestions@

0, Register measurement Fo: o* assignment roce.ure on t+e BSC, In<uire t+e

sei!ure con.itions o* TCHHs an. TCH%s, 2, A.. TCH%s roer"&, ecrease

TCHHs accor.ing to t+e sei!ure con.itions o* TCHHs, 5, 'it+ t+e MS

suort on t+e +a"*8rate sc+eme in t+e current network an. wit+ t+e consent o*

t+e customer- use on"& +a"*8rate c+anne"s to .ecrease *u""8rate c+anne"




INT#RNA$

sei!ures :ase. on ACPOO$ or .ata con*iguration on t+e BSC, Sei!ing

TCHHs a**ects t+e seec+ <ua"it&,

Summary@ Insu**icient c+anne" resources can cause congestion- w+ic+

a**ects assignment success rate,

9,6 $ow Assignment Success Rate Cause. :& Insu**icient Ater Resources

FProlem !escription

T+e assignment success rate is "ow a*ter t+e BSC9;;; is cut o/er at a site,

T+e TCH assignment success rate er BSC is on"& a:out 9;, T+e

+an.o/er success rate is "ow, Making ca""s is .i**icu"t,


Troules*ooting.

0, C+eck t+e settings o* t+e arameters re"ate. to assignment@ ,llo'

&eassign an. T3(";- an. *in. t+at t+e& are norma",

2, T+e BSC9;;; is con*igure. wit+ a.ati/e circuit oo", T+e site is in

circuit oo" 23, T+ere*ore- e=c"u.e t+e imact o* t+e circuit oo" an. seec+

/ersion,

5, C+eck t+e BSC a"arms, T+e resu"t s+ows t+at a"" e<uiment run norma""&,

6, C+eck t+e tra**ic statistics an. *in. t+at t+e TCH congestion .oes not

occur, T+ere*ore- e=c"u.e t+e situation o* c+anne" una/ai"a:i"it&, T+e

assignment *ai"ure main"& occurs on t+e A inter*ace, T+e .i**erence :etween

t+e assignment re<uests sent :& t+e MSC an. t+e assignment comman.s

sent :& t+e BSC is great- t+at is- man& assignment comman.s are not sent,

C+eck t+e status o* t+e A inter*ace an. *in. t+at t+e trunk is norma" an. t+e

resources are su**icient, In t+e current network- t+e TC is con*igure.

remote"& an. t+e transmission resources are insu**icient, C+eck t+eresources on t+e Ater inter*ace an. *in. t+at t+e BSC is con*igure. wit+ on"&

two #0s an. 039 trunks, T+e tra**ic /o"ume o* *au"t occurrence time is 091

#r", T+ere*ore- we can in*er t+at t+e resources on t+e Ater inter*ace are

insu**icient- w+ic+ is acknow"e.ge. :& t+e tracing signa"ing, Increase t+e




INT#RNA$

transmission resources on t+e Ater inter*ace an. *in. t+at t+e assignment

success rate is u to 77 ,

Summary@ In t+e BSC52- t+e trunks on t+e A an. Ater inter*aces are

acti/ate. correson.ing"&- t+at is- t+e resources on t+e A an. Ater inter*aces

are t+e same, I* t+e trunks are insu**icient- t+e MSC .oes not sen. t+e

Assignment Re<uest message :ut t+e isconnect message wit+ t+e cause

/a"ue resource unavailale a*ter t+e MSC recei/es t+e S#TP message,

T+ere*ore- note t+e ratio o* tra**ic /o"ume to t+e Ater resources to a/oi.

"imite. communication :ecause o* insu**icient Ater resources,

9,1 $ow Assignment Success Rate Because o* Con*iguration o* Ha"*8rate

C+anne"s

FProlem !escription

In a new"& .e"o&e. BTS in town A- t+e tra**ic /o"ume is +ig+ a*ter t+e BTS

is starte., '+en t+e +a"*8rate sc+eme is ena:"e.- t+e su:scri:ers com"ain

t+at t+e mo:i"e +ones cannot make ca""s *re<uent"& e/en t+oug+ t+e signa"s

are strong, T+e assignment success rate is "ow,


Troules*ooting.

0, C+eck t+e a"arm conso"e an. *in. t+at no a"arm is generate., T+e TR

a/ai"a:i"it& is 0;;- w+ic+ in.icates t+at t+e ro:a:i"it& o* TR *au"ts is

sma"",

2, Euer& &,C/ 4in) ,ccess Level an. *in. t+at it is set to I("% .Bm, T+e

su:scri:er reorts t+at t+e mo:i"e +one +as *u"" signa" strengt+ in.icators,

T+ere*ore- t+e error in arameter setting is e=c"u.e.,

5, Euer& t+e status o* inter*erence :an.s an. :a"ance :etween t+e u"ink an.

t+e .own"ink, T+e resu"t s+ows t+at t+e& are norma", Imme.iate assignment

success rate is norma" w+i"e TCH assignment success rate is "ow,

6, Euer& t+e tra**ic /o"ume an. congestion rate on t+e SCCH an. TCH, T+e

resu"ts s+ow t+at TCH congestion rate is +ig+, T+e num:er o* initia""&

con*igure. TCHHs is great w+i"e t+at o* TCH%s is sma"", T+e .i**erence

:etween success*u" TCH sei!ures (on"& *u""8rate) an. TCH sei!ure re<uests




INT#RNA$

(on"& *u""8rate) is great, T+ere*ore- it is .ou:te. t+at static +a"*8rate c+anne"s

ma& :e con*igure.- w+ic+ makes some MSs suorting on"& *u""8rate ser/ices

una:"e to sei!e t+e TCH%s,

1, C+eck t+e .ata con*iguration to /eri*& t+e rece.ing .ou:t, C+ange t+e

c+anne" t&e an. co""ect t+e *ee.:ack *rom t+e su:scri:ers, T+e *au"t is

recti*ie.,

Summary@ O:tain .etai"e. in*ormation on recent oerations :e*ore

recti*&ing t+e *au"ts, T+e *au"ts ma& :e cause. :& incorrect con*iguration o*

re"e/ant arameters, etai"e. ana"&sis o* tra**ic statistics +e"s "ocate t+e

*au"ts <uick"&,

; eedac?s on ,ssignment Success &ate

I* assignment success rate is too "ow- sen. t+e .ata .escri:e. in t+e

*o""owing ta:"e to t+e 'CMAGSM Network Per*ormance Researc+ et,

C+eck Item Remarks Purose

So*tware /ersion So*tware /ersion o* t+e BSC

an. BTS

To c+eck w+et+er t+e so*tware /ersion is

*au"t&,

ata con*iguration

ta:"e

,.at *i"e To c+eck t+e otimi!ation arameters an.

ower con*iguration,A"arm in*ormation A"arms re"ate. to +ar.ware-

c"ock- an. transmission (se"*8

c+eck)

To c+eck w+et+er suc+ a"arms e=ist in t+e

*au"t& ce"", Suc+ a"arms s+ou". :e c"eare.,

Tra**ic statistics Assignment success rate an.

c+anne" a/ai"a:i"it&

To o:ser/e t+e tra**ic measurement resu"t an.

c+eck *or congestion or inter*erence,

Signa"ing RS$ tracing .ata To c+eck t+e reasons o* assignment *ai"ures,

ri/e test .ata ,"og(,C#$$) or ,ant *i"e To o:ser/e t+e .ri/e test .ata an. c+eck *or

inter*erence or co/erage ro:"ems,

Ot+ers #ngineering arameter ta:"es

an. #8mas

To c+eck t+e geogra+ica" in*ormation o* t+e

NASTAR,




INT#RNA$

Aen.i=@ MaFor Parameters A**ecting TCH Assignment Success Rate

Categor& Parameter

Ca"" Contro" Assignment Ce"" $oa. u.ge #na:"e

irecte. Retr& $oa. Access T+res+o".

A""ow Reassign

Ma= Assignment Retr& Times

Seec+ >ersion

C+anne" Management TCH Tra**ic Bus& T+res+o".

AMR TCHH Prior A""owe.

Ot+er Parameters T50;3(ms)

Ce"" irecte. Retr& %or:i..en T+res+o".

T50;5A(ms)

Basic Parameters SCCH &namic A""ocation A""owe.

irecte. Retr& A""owe.

MSC Parameters Eueuing A""owe.

Preemtion A""owe.

12 GSM BSS Network KPI (TCH Assignment Success Rate) Optimization Manual2.doc

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