Call Fail Analysis Guideline

8/9/2019 Call Fail Analysis Guideline

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HUAWEI RNP TEAM HUAWEI Confidential 1

Call Failure Analysis

Guideline


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The Call Fail Reason can be classified into several reason :

1. Coverage and Interference Proble.! Coverage Hole and U" Interference.

#. I$ro$er radio and neighbor $araeter setting.

! %issing neighbor& 'rong setting of neighbor cell& i$ro$er setting of

()*alin and (r+levin.

! "o' setting of $reable Po'er Ra$ ,te$& "o' setting for Coon

Channel.! "o' ,etting of Initial ,IR Target.

-. E)*i$ent and Interface Proble.

! Abnoralit of E)*i$ent Cloc/0 ,P0CPU& Ins*fficient RA2 3oard

Reso*rces& Transission Alar.

4. 2et'or/ Eleent and Interface Reso*rce.

! High Cell "oad& High CE Utili5ation& High IU3&IU C,0P, Utili5ation.6. Config*ration Inconsistenc.

! Inconsistent 2*ber of AA"#PATHs across IU0IU3 Interface.

! PATH I and 2,AP Address Config*ration Error of AA"#PATH.

A. Call Fail Reason


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The Call Fail Reason can be classified into several reason :

1. Coverage and Interference Proble.! RRC.FailConnEstab.2oRe$l

! 7,.RA3.FailEstC,.RIPFail

#. E)*i$ent and Interface Proble.

! 7,.RRC.Re8.R".Fail& 7,.RRC.Re8.T2".Fail9I*b $roble.

! 7,.RA3.FailEstabC,.R2"& 7,.RA3.FailEstabC,.T2".

-. 2et'or/ Eleent and Interface Reso*rce.

! 7,.RRC.Re8.Po'er.Cong& 7,.RRC.Re8.U"IU33andCong&

7,.RRC.Re8."IU33andCong& 7,.RRC.Re8.U".CE.Cong&

7,.RRC.Re8.".CE.Cong& 7,.RRC.Re8.Code.Cong.

! 7,.RA3.FailEstCs.Po'er.Cong&

7,.RA3.FailEstab.C,."IU33and.Cong&7,.RA3.FailEstab.C,.U"IU33and.Cong&

7,.RA3.FailEstCs.U"CE.Cong& 7,.RA3.FailEstCs."CE.Cong&

7,.RA3.FailEstCs.Code.Cong

A. Call Fail Reason Statistic Based


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4. Relocation Proble.

! 7,.RA3.FailEstC,.Relo

6. Ca$abilit Proble.

! 7,.RA3.FailEstC,.Uns$ .

;. ,et*$ redirection $roble.

! 7,.RRC.Re8.Redir.Inter.Att 7,.RRC.Re8ect.Redir.Intrat

7,.RRC.Re8ect.Redir.,ervice.


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.

B. Call Fail

Analysis Flo


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The ethodolog to anal5e Call ro$ $roble containing several ste$ belo':1. ata Pre$aration

#. Traffic Analsis.

-. E)*i$ent Analsis.

4. Coverage and Interference Analsis.

6. ,ignalling Analsis

C. Met!odolo"y

! Ho*rl0ail ,tatistic 9C, RA3 assignent fail*re $er cell& RRC connection re8ect $er cell&

Cell T< and R< Po'er& etc.

! The latest ,ite %a$& 2eighbor relation& and cell config*ration0$araeter data.! ,ingle s*bscriber tracing recorded b R2C.

! CHR recorded b R2C.

! Active and Histor Alar.

! ata files collected b T.

C.# $ata Pre%aration


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! The Traffic analsis is related to CE *tili5ation& IU3&IU Utili5ation& and Code Utili5ation. This

Inforation 'e can get fro the ail0Ho*rl ,tatistic.

! The RRC Re8ection Ca*se related to traffic *tili5ation can 'e get in Ra' co*nter belo':

> 7,.RRC.Re8."0U"IU33andCong ? I*b *tili5ation

> 7,.RRC.Re8.Po'er.Cong ? Cell "oad

> 7,.RRC.Re8.U".CE.Cong ? U" CE *tili5ation

> 7,.RRC.Re8.".CE.Cong ? " CE *tili5ation

> 7,.RRC.Re8.Code.Cong ? Code Utili5ation.

! The RA3 Fail Ca*se related to traffic *tili5ation can 'e get in Ra' co*nter belo':

> 7,.RA3.FailEstCs.Po'er.Cong ? Cell "oad

> 7,.RA3.FailEstCs.U"CE.Cong ? U" CE Utili5ation

> 7,.RA3.FailEstCs."CE.Cong ? " CE Utili5ation

> 7,.RA3.FailEstCs.Code.Cong ? Code Utili5ation. > 7,.RA3.FailEstab.C,."0U"IU33and.Cong ? I*b *tili5ation

C.& Tra''ic Analysis


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! Radio net'or/ signaling incl*des signaling of fo*r standard interfaces of UU& IU IU3 and IUR.

When an abnoralit occ*rs in the signaling flo'& 'e can chec/ 'hich $art of signaling flo' is

issing.

! The issing of signaling flo' sho*ld be correlated to UU&IU3&IU& and IUR interface $roble.

! According to single s*bscriber tracing essages& the call dro$ is defined as:

1 RRC C22ECTI2 RE(UE,T FAI"URE

R2C Fails on receiving U" essage of RRC C22ECTI2 ,ETUP C%P"ETE.# RA3 A,,I2%E2T RE(UE,T FAI"URE

C2 Fails on receiving U" essage of RA3 A,,I2%E2T RE,P2,E

Chec/ the call dro$ tie and the signaling essage before call dro$ for f*rther analsis.

! The Isi trace tool 'ith all interface essage and onitoring /$i9CPICH R,CP& CPICH EC2&

U" ,IR& U" T< PWR& and " T< CE PWER hel$ing *s disting*ishing Call Fail Reason.

The Call Fail related to Air Interface or not related to Air Interface $roble.

C.- Si"nallin" Analysis


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Call Fail Analysis Guide

Usin" Si"nallin" IMSI Trace


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! It is ,ho's details of all calls based on o*t$*t fro Trace %anageentGInterface Trace

Tas/GUE.

! Provide convenient& PCbased analsis

1. Call %essage Event

#. The do'nlin/ CPICH R,CP and EC2 istrib*tion.

-. U" ,IR istrib*tion.

4. UE T+ Po'er distrib*tion.

6. " T+ Code P'r

IMSI Trace on MT


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Trace /ieer 'or Post Processin" IMSI Trace o"

# - 4 6

1. Call %essage Event#. The do'nlin/ CPICH

R,CP and EC2

istrib*tion.

-. U" ,IR istrib*tion.

4. UE T+ Po'er distrib*tion.

6. " T< Code P'r.

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Call Messa"e E,ent0 RncId0ac0Cell Id

Identi'ication

! Filter The %essage b

RA2AP"CATI2REPRT0RA2API2ITIA"UE%E,,AE essage.

! Convert The HE< val*e into EC val*e.



Call Messa"e E,ent0 Call Fail Identi'ication

!,nchroni5e the Tie of Call Fail.

! Call Fail %essage defined as:

1. RRC C22ECTI2 RE(UE,T FAI"URE

R2C Fails on receiving U" essage of RRC C22ECTI2 ,ETUP

C%P"ETE.

#. RA3 A,,I2%E2T RE(UE,T FAI"URE.

C2 Fails on receiving U" essage of RA3 A,,I2%E2T RE,P2,E.



Call Messa"e E,ent0 RRC.FailConnEsta1.NoRe%ly

2RNC does not recei,e RRC C3NNECT SETUP C3MPETE 4

! Filter The %essage b RRCRRCC22ECTRE(UE,T& RRCRRCC22,ETUP& andRRCRRCC22ECT,ETUPC%P.

! If 2o RRCRRCC22ECT,ETUPC%P after RRCRRCC22,ETUP.

! The ,erving EC2 is 14 to 1-.6 d3.



Call Messa"e E,ent0 RAB SETUP FAI2Failure

in Radio Inter'ace %rcedure2#+44! Filter The %essage b RA2APRA3A,,I2%E2TRE,P2,Era3

Failed"istGca*seGisconnectGradio2et'or/914Fail*re in Radio Interface Proced*re.

! Chec/ All Trace 7ie'er PI9R,CP&EC2&U" ,IR& etc and Alar Iss*es.



! The 3rea/do'n fro RF Proble.

! Chec/ing CPICH and R,CP istrib*tion.

! If R,CP B?D6 d3 Consider as Poor Coverage& Chec/ for issing neighbor and nearb ,ite $roble.

! If EC2 B?1# d3 and R,CP G?@ d3 consider as " Interference0Pilot Poll*tion. rive Test forverification is needed.

3ad R,CP

and EC2

istrib*tion

Co,era"e and Inter'erence Analysis

CPICH RSCP and ECN3




! Chec/ing U" T< PWR istrib*tion.

! %a+ UE T< PWR is to #4 d3.

! If UE T< PWR ore than 6 d3 consider as high UE T< PWR.

! High UE T< PWR can be d*e to E+cessive U" Coverage or High U" Interference& Chec/ if an issingneighbor or nearb ,ite Proble.

High U" T<

PWR

istrib*tion


UE T5 P3WER




! Chec/ing U" ,IR istrib*tion.

! The ,IR Target for this ,ervices is 1.6 d3.

! If The ,IR %eas*red "ess than 1.6 d3 can be d*e to E+cessive U" Coverage or High U" Interference&Chec/ an issing neighbor or neighbor ,ite Proble

3ad U" ,IRistrib*tion


U SIR




! Chec/ing " T< Code Po'er istrib*tion.

! The T< CE PWER %A< 7al*e for this A%R 1#.# is e)*al to CPICH PWER 9e+a$le --d3 .

! The T< CE PWER %I2 7al*e for this A%R 1#.# is e)*al to 1@ d3

! If The T< Code Po'er Reaching near to CPICH PWER can be d*e to Poor Coverage0Fringe Cell0"Interference. Chec/ an issing neighbor or neighbor ,ite Proble.

High " T<

CE

PWER

istrib*tion


$ T5 C3$E P3WER

Documents

Call Fail Analysis Guideline