WCDMA RNO Access Problem Analysis Guidance

8/11/2019 WCDMA RNO Access Problem Analysis Guidance

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Huawei Technologies Co. Ltd.

Product Version Confidential level

V100R001 For internal use only

Product name: WC!" R#P Total $% &ages

WC!" R#' "ccess Pro(lem

"nal)sis *uidance+or internal use onl)

Pre&ared () ,R#P -"#" ate /00$-10-0

Reviewed () ate

Reviewed () ate

*ranted () ate

Huawei Technologies Co. Ltd.

"ll rights reserved


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WCDMA RNO Access Problem Analysis Guidance For internal use only

Revision Record

ate Revision

version

Change escri&tion "uthor

2003!00" !#00 First dra$t com%leted &iao An'ian(

2003!0!) 2#00 Revision based on comments &iao An'ian(

2003!!!! 3#00 Revision based on revie* comments &iao An'ian(

!)"2! Con$idential Pa(e 2 + ,otal 3-


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,able o$ Contents

!Fore*ord #####################################################################################################################################################.

2Access Problem Analysis Process#################################################################################################################.2#!Pre%aration be$ore Analysis#####################################################################################################################.

2#2Access Problem Analysis Met/ods##########################################################################################################2#2#! ,ra$$ic 1tatistics Data Analysis#########################################################################################################"

2#2#2 1i(nalin( Flo* Analysis##################################################################################################################!0

2#2#3 'ui%ment Analysis#########################################################################################################################!-

2#2#) Covera(e Analysis###########################################################################################################################222#2# Po*er Control 4n$ormation Analysis###############################################################################################22

2#2#. Access Al(orit/m Parameter Analysis############################################################################################2

2#2# 5 C/aracteristics Analysis############################################################################################################2.3Analysis o$ Command Reasons $or Access Problems################################################################################2.

3#!Net*or6 Reasons###################################################################################################################################2.

3#!#! Dead 1%ot in 1i(nal Covera(e#########################################################################################################2.

3#!#2 ,oo 1tron( 5%lin6 and Do*nlin6 4nter$erence 1i(nals 7ist#########################################################23#!#3 Access Problems Caused by Cell 8oad###########################################################################################2

3#2Radio Parameter 1ettin(s#######################################################################################################################2"

3#2#! ,oo 9i(/ 1ettin(s o$ :'ualmin and :r7levmin#############################################################################2"3#2#2 4m%ro%er 1ettin(s o$ Access ,/res/old###########################################################################################2"

3#2#3 4na%%ro%riate 1ettin( o$ Preamble Po*er Ram% 1te% and Retransmission ,imes#########################2-

3#2#) 4na%%ro%riate 1ettin( o$ Ad;acent Cells##########################################################################################30

3#2# 4na%%ro%riate 1ettin( o$ 1ync/roni


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8ist o$ ,ables

,able ! Common C/annel Po*er Allocation Ratio###############################################################################3!

,able 2 Over/ead Pro%ortion $or ac/ 8ayer on 45> 4nter$ace###########################################################3)

8ist Fi(ures

Fi(ure ! ,ra$$ic 1tatistics Analysis Flo*##################################################################################################-

Fi(ure 2 1c/ematic Dia(ram o$ Radio 8ayer 1i(nalin(#########################################################################!!Fi(ure 3 1c/ematic dia(ram o$ trans%ort net*or6 layer si(nalin( analysis###########################################!2

Fi(ure ) 1in(le 5ser Fault 8ocation ,ool###############################################################################################!3

Fi(ure 1i(nalin( Flo* $or RRC 1etu% in ac/ 8ayer o$ Dedicated C/annel#####################################!)Fi(ure . Problem Analysis Flo* o$ RRC 1etu% in Dedicated C/annel#################################################!

Fi(ure 5 Air 4nter$ace Messa(e ,racin(############################################################################################!

Fi(ure " Access Problem Caused by Covera(e Restriction####################################################################2)

Fi(ure - Normal Access Process#############################################################################################################2Fi(ure !0 5 Aut/entication and 1ecurity Mode Process########################################################################3.

!)"2! Con$idential Pa(e ) + ,otal 3-


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WCDMA RNP Access Problem Analysis Guidance

2e) wordB access %rocess+ %roblem analysis+ cell searc/in(+ cell selection and reselection+ random access

"(stractB ,/is document analy


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1 +oreword

4n WCDMA net*or6 o%eration+ lo* call setu% rate and di$$icult access are t/e /ot com%laints $rom

subscribers+ as *ell as t/e direct re$lection o$ t/e 'uality o$ t/e radio net*or6# ,/is document analy site ad;ustment @distance bet*een Node> sites+

a setu%+ t/e success rateo$ RRC setu% can re$lect better t/e radio access %er$ormance+ because t/e %rocess o$ RRC connection

setu% is basically t/e %rocess o$ cell searc/in(+ selection and reselection+ initiation o$ random access+ etc#+

*/ic/ occur on t/e air inter$ace+ */ile t/e success rate o$ RA> setu% /as more relations *it/ t/e net*or6

$actors suc/ as e'ui%ment+ transmission+ etc#+ */ic/ are muc/ less li6ely to cause access %roblems#

/ "ccess Pro(lem "nal)sis Process

/.1 Pre&aration (efore "nal)sis

Pre%aration be$ore access %roblem analysis is to collect in$ormation about net*or6 as su$$icient as

%ossible be$ore analysis o$ net*or6 access %roblems+ so t/at t/e (oals o$ net*or6 o%timi


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For t/e net*or6 in service+ it may /ave been o%timis and RNCs are consistent+ and ensure */et/er t/e entire

net*or6 version is consistent and */et/er all Node>s are usin( t/e same version includin(

%atc/ releases#

4n case o$ o%timi is %ut into service+ */et/er t/e bac6(round noise o$ t/e

Node>s /as been calibrated @calibrate t/e receivin( c/annel (ain+ and */et/er t/e standin(

*ave ratio o$ t/e antennas /as been tested#

4n case o$ o%timi


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$or access %roblems can be $le7ibly a%%lied durin( actual %roblem location %rocesses accordin( to t/e

actual conditions+ and it is unnecessary to stic6 to t/e orders#

2#2#! ,ra$$ic 1tatistics Data Analysis

C/ec6 RNC tra$$ic statistics data callin( setu% success rate# ,/e $ormula o$ t/e callin( setu%

success rate is as $ollo*sB

E!00= ccRateRABSetupSuccRateRRCSetupSuuccRateCallSetupS

W/ere+

E!00=ervicesfour QoS sts in allRRC requesNumber of

ervicesfour QoS sup in allRRCs setNumber ofccRateRRCSetupSu

E!00=ervicesfour QoS sts in allRAB requesNumber of

ervicesfour QoS sup in allRABs setNumber ofccRateRABSetupSu

4n t/e same *ay+ statistics o$ t/e callin( setu% success rate o$ eac/ :o1 can be im%lemented

res%ectively# ,/e si(n o$ RRC connection setu% success is t/e RRC Connection 1etu% Com%lete

messa(e# ,/ere$ore+ t/e RRC connection setu% success rate is calculated t/rou(/ statistics o$ t/e number

o$ t/e RRC Connection 1etu% Com%lete messa(es and t/e number o$ t/e RRC Connection Re'uest

messa(es# ,/e si(n o$ RA> assi(nment is t/e RA> Assi(nment messa(e @t/e content o$ t/e messa(e is

RA> assi(nment# ,/ere$ore+ t/e RA> assi(nment success rate is calculated t/rou(/ t/e statistics o$ t/e

number o$ success$ul RA>s setu% in t/e RA> Assi(nment Res%onse messa(e and t/e number o$ RA>

Assi(nment Re'uest messa(es#

,/is inde7 statistics is celloriented and it re$lects t/e call setu% situation o$ t/e net*or6# 1tatistics

can be eit/er im%lemented to(et/er $or t/e $our :o1 services o$ Conversation+ 1treamin(+ 4nteractive and

>ac6(round+ or im%lemented res%ectively# Analysis o$ tra$$ic statistics data can (ive a rou(/ direction to

t/e solution o$ %roblems $rom t/e statistics %oint o$ vie*# Amon( tra$$ic statistics data+ in addition to t/e

%ro%ortion data+ t/e statistics t/e ori(inal counter data @i#e# t/e number o$ connection re'uest messa(es

received by RNC $rom RRC s/ould also be em%/asiesides+ *e s/ould be $amiliar *it/ t/e

corres%ondin( relations bet*een t/e ori(inal counter data and t/e %ro%ortion data+ t/e meanin(s o$ t/ese

data and t/e %osition o$ t/ese data in t/e setu% %rocess o$ si(nalin( service#

,/e callin( setu% success rate is obtained $rom t/e %roduct o$ RRC setu% success rate and RA> setu%

success rate# ,/is can be sim%li$ied durin( t/e actual tra$$ic statistics analysis %rocess# Namely+ RRC setu%

success rate and RA> setu% success rate can be analyac6(round can be %er$ormed se%arately# ,/rou(/ t/e analysis

on t/e tra$$ic statistics data related to RRC setu% and RA> setu%+ *e can locate t/e %ossible %arts o$ access

%rocess */ere %roblems /ave occurred and determine t/e direction $or $urt/er analyses# A$ter all+ tra$$ic

statistics analysis is an a%%ro7imation analysis met/od in t/e sense o$ statistics# ,ra$$ic statistics analysis o$

access %rocess is s/o* in Fi(ure ! #

!)"2! Con$idential Pa(e " + ,otal 3-


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Figure 1 Traffic Statistics Analysis Flow

RRC setu% success rate re$lects t/e subscriber call success rate o$ t/e net*or6 to a (reat e7tent+

because RRC setu% is closer to t/e radio inter$ace $rom t/e access %oint o$ vie*+ and t/e %robability o$

e7ce%tions is /i(/er t/an t/at o$ RA># RRC setu% success rate may /ave t*o o%%osite be/aviors in tra$$ic

statisticsB one is t/at tra$$ic statistics s/o*s /i(/ access rate+ but t/e subscribers still com%lain about access

di$$iculty# ,/is is because t/e access %rocess $ailed be$ore RRC CONNC, R:51, is sent# 4$ RRC

CONNC, R:51, is added durin( creation o$ a %er$ormance statistics tas6+ t/is value *ill be $ound

muc/ smaller t/an t/e normal statistics value @or t/e e7%erience value# ,/e reason is t/at tra$$ic statistics

cannot re$lect t/is situation *it/ t/e inde7 o$ RRC setu% success rate i$ 5,RAN /as not received RRC

setu% re'uest messa(e+ but it only su%%orts 'uery o$ t/e statistics inde7 o$ t/e number o$ RRC connection

re'uest messa(es# 4n t/is case+ mainly analy setu% mainly include messa(e interc/an(e t/rou(/ (round inter$ace and

*it/in t/e e'ui%ment# ,/e $ormula o$ R> setu% is as $ollo*s# 4$ R> setu% success rate is /i(/ */ile RA>

!)"2! Con$idential Pa(e - + ,otal 3-


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setu% success rate is lo*+ c/ec6 t/e e'ui%ment condition and t/e trans%ort layer con$i(uration o$ t/e

(round inter$ace#

Amon( accessrelated tra$$ic statistics data+ in addition to RRC setu% success rate and RA> setu%

success rate and related ori(inal counter data+ ot/er statistics data related to RRC and RA> can also be

analy setu% $ailure because o$ con(estion# 4$ t/e con(estion

ratio is /i(/+ it means t/at t/e cell is overloaded# For detailed descri%tions+ re$er to t/e relevant document

about tra$$ic statistics indices+HUAWEI 3 WC!"A #AR$% #erformance "ana&ement In'ices ( RNC)

2#2#2 1i(nalin( Flo* Analysis

,/e $ailed %art o$ t/e entire access %rocess can be vie*ed directly t/rou(/ si(nalin( $lo*# ,/rou(/

si(nalin( $lo* analysis+ most access %roblems can be solved+ includin( restricted do*nlin6 ca%acity# ,/e

analysis ste%s o$ si(nalin( $lo* basically $ollo*s t/e to% layer bottom layer+ e7terior to interior+ and

control %lane to user %lane %rinci%le# ,o% layer to bottom layer re$ers to analy


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%rintin( and messa(e anot/er %ossible reason may be %oc6et loss due to Node> decodin( error or %ac6et

loss due to 45> inter$ace @can be observed *it/ a net*or6 /a*6#

2#2#2#2 Analysis o$ standard si(nalin( o$ radio net*or6 layer

Radio net*or6 si(nalin( includes si(nalin( o$ $our standard inter$aces o$ 55+ 45 45> and 45R#

W/en an abnormality occurs in t/e si(nalin( $lo*+ o%en t/e messa(e %ac6et traced on t/e maintenance

console and c/ec6 t/e relevant 4s in t/e messa(e $or abnormal value assi(nment# s%ecially */en one

%arty in messa(e interaction received a $ailure messa(e or a re;ect messa(e+ t/e cause value o$ $ailure can

be obtained directly t/rou(/ messa(e resolution+ so as to %re%are $or t/e subse'uent location ste%s# As

s/o*n in Fi(ure + in t/e R8 1,5P R:51, messa(e+ t/e de$ault value o$ t/e u%lin6 initial sir tar(et

/as been al*ays 0d>+ */ic/ causes outo$sync o$ 5 durin( t/e access %rocess# ,/e reason is t/at t/e out

loo% %o*er control la(s be/ind t/at o$ t/e in loo% %o*er control+ and in t/is too lo* a 14R settin( durin(

t/is %eriod o$ time *ill cause a lo* emission %o*er o$ 5 u%lin6 dedicated c/annel+ resultin( in u%lin6

outo$sync#

Figure 2 Schematic Diagram of Radio Layer Signaling

2#2#2#3 Analysis o$ 1tandard 1i(nalin( o$ ,rans%ort Net*or6 8ayer

,rans%ort net*or6 layer si(nalin( includes 1AA8 and A8CAP si(nalin( tracin( o$ t/e 45> inter$ace+

and 1AA8+ A8CAP+ M,P3> and 1CCP si(nalin( tracin( o$ t/e 45 and 45R inter$aces# 4$ a $ault occurs in

t/e trans%ort net*or6 layer+ $or e7am%le+ AA82 C9ANNA8 setu% $ailure+ t/e trans%ort layer si(nalin( can

be traced $or analysis# As s/o*n in Fi(ure 3+ t/e 1,A>8419 R:51, messa(e o$ A8CAP on t/e 45>

inter$ace is traced# ,/e NA1P address at t/e Node> end is

O73-02030)00.00"0-000-0"00.00)03020!00# 4$ t/e NA1P addresses at bot/ sides are not

consistent durin( data ne(otiation bet*een RNC and Node>+ AA82 C9ANNA8 setu% $ailure *ill occur+

and RNC *ill send RRC CONNC, R&C, messa(e to 5+ *it/ t/e cause value bein( 5N1PC4F4D#

!)"2! Con$idential Pa(e !! + ,otal 3-


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1imilarly+ i$ su$$icient si(nalin( cannot be obtained t/rou(/ radio net*or6 si(nalin( analysis+ t/e $ollo*in(

trans%ort net*or6 layer s/ould be analy


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Figure Single !ser Fault Location Tool

2#2#2# RRC Connection 1etu% 1i(nalin( Analysis Process

RRC setu% is an im%ort issue in access %rocess o%timiAP+

:#AA82 and FP %rotocols+ and t/e $ailure o$ a sin(le %art *ill lead to t/e $ailure o$ t/e entire %rocess#

!)"2! Con$idential Pa(e !3 + ,otal 3-


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UE NODEB MSC

RRC RRC

NBAP NBAP

NBAP NBAP

Q.AAL2 Q.AAL2

Q.AAL2 Q.AAL2

DCH-FP DCH-FP

DCH-FP DCH-FP

RRC RRC

RRC RRC

NBAP NBAP

RRC CONNECT REQUEST

RADIO LINK SETUP REQUEST

RADIO LINK SETUP RESPONSE

ESTABLISTH REQUEST

ESTABLISH CONFIRM

RADIO LINK RESTORE

RRC CONNECT SETUP

RRC CONNECT SETUP COMPLETE

DOWNLINK SYNCHRONISATION

UPLINK SYNCHRONISATION

Figure " Signaling Flow for RR# Setup in $ach Layer of Dedicated

#hannel

For RRC setu% in dedicated c/annel+ + accordin( to t/e si(nalin( $lo* s/o*n in Fi(ure + %roblem

analysis can be %er$ormed in t/e $ollo*in( ste%s+ as s/o*n in Fi(ure .# 1ite en(ineers can locate t/e rou(/

ran(e o$ t/e %roblem and collect t/e relevant onsite location in$ormation accordin( to t/e $lo* c/art# 4$ it

is necessary to ma6e inde%t/ location on t/e site+ re$er to WC!"A E8pert roup9 WC!"A S4stem

#roblem :ocation "anuel9 ,--3-/-, E'ition)

!)"2! Con$idential Pa(e !) + ,otal 3-


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Figure % &ro'lem Analysis Flow of RR# Setup in Dedicated #hannel

! RNC $ails to receive RRC CONNC, R:51, messa(esB ,/rou(/ 55 inter$ace tracin( o$

RNC+ no RRC connect re'uest messa(e is $ound# Firstly+ c/ec6 *it/ net*or6 /a*6 */et/er t/e

RRC connect re'uest messa(e /as been sent to t/e 45> inter$ace# 4$ it is $ound+ analy internal abnormality# ,/is can be

located *it/ t/e /el% o$ 5 bac6(round %rint and Node> debu((in( console i$ an RRC connect

re'uest messa(e a%%ears on t/e 45> inter$ace+ it is %ossibly because o$ %oc6et loss on t/e 45>

inter$ace or RNC internal abnormal %rocessin(# C/ec6 %oc6et loss on t/e 45> inter$ace *it/

!)"2! Con$idential Pa(e ! + ,otal 3-


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net*or6 /a*6 $or t/e abnormal RNC internal %rocessin(+ vie* t/e RNC alarm subsystem+ board

serial %ort %rintin(+ board o%eration lo( and internal messa(e tracin(#

2 Radio lin6 setu% $ailureB 4t is not li6ely to occur# 9o*ever+ i$ it occurs+ a %ossible reason is t/e

internal abnormality o$ RNC or Node># =ie* t/e alarm subsystem and %er$orm radio lin6 toestablis/ messa(e resolution# 4$ it is necessary to ma6e an inde%t/ location+ t/e internal $lo* can

be located by usin( t/e debu((in( console o$ RNC and Node>#

3 AA82 lin6 setu% $ailure o$ bearer air inter$ace si(nalin(B C/ec6 t/e data con$i(uration o$

AA82PA,9 o$ RNC and Node>+ em%/asi+ A882PA,9 4D+ P=C $lo* and ty%e+ AA82PA,9 band*idt/ and C4D consum%tion#

) DC9 FP sync/roni inter$ace @*it/ net*or6 /a*6+ AA82 lin6 o$ 45>

inter$ace+ !?,! status and Node> %rocessin(+ to locate t/e %roblem#

. RNC $ails to receive RRC CONNC, 1,5P COMP8, messa(eB Re$er to 1ection rrorB

Re$erence source not $ound+ 1i(nalin( Analysis Cases#

RNC $ails to receive R8 R1,OR messa(eB 4$ RNC $ails to receive t/e R8 R1,OR messa(e

*it/in a certain %eriod o$ time+ Node> u%lin6 sync/roni


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4$ RNC $ails to receive t/e RRC CONNC, 1,5P COMP8, messa(e $rom 5+ t/ere are t/ree

%ossible reasonsB 5 $ails to send t/e messa(e+ t/e messa(e is lost durin( transmission+ and 5 $ails to

receive RRC CONNC, 1,5P#

5 $ails to send t/e RRC Connect 1etu% Com%lete messa(e#

8ocation ste%sB

,/ere are t*o *ays to identi$y */et/er 5 /as received t/e RRC CONNC, 1,5P messa(eB

! C/ec6 */et/er t/e %rinted in$ormation is available on t/e 9y%er,erminal indicatin( t/at t/e RRC

CONNC, 1,5P messa(e /as been received# 4$ suc/ in$ormation is not available+ t/e 1,5P messa(e

/as not been received#

O%en t/e air inter$ace messa(e re%orted by RRC+ and c/ec6 t/e RRC CONNC,4ON R: messa(e

is $ollo*ed by t/e RRC CONNC,4ON 1,5P messa(e# 4$ so+ c/ec6 */et/er t/e 5 4Ds o$ t/ese t*o

messa(es are consistent# 4$ t/ey are not consistent+ t/e 1,5P messa(e /as not been received @A$ter

receivin( t/e air inter$ace messa(e+ 5 *ill re%ort to t/e bac6(round $irst be$ore it %rocesses t/e messa(e+

so t/e 1,5P messa(e seen at t/e bac6(round is not necessarily $rom t/is 5# 4t is necessary to com%are

t/e 5 4Ds $or con$irmation#

,/e air inter$ace messa(e re%orted by RRC is as t/e $ollo*sB

Figure ( !$ Air )nterface *essage Tracing

2 A$ter 5 receives t/e 1,5P messa(e+ it releases R>0 @random access c/annel+ starts %o*er

control a$ter t/e com%letion o$ release be$ore t/e %rotection timer times out+ and %roceeds *it/ establis/in(

!)"2! Con$idential Pa(e ! + ,otal 3-


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do*nlin6 dedicated c/annel @con$i(uration o$ radio lin6 and transmission c/annel and MAC# A$ter RRC

receives all t/e con$i(uration %rimitives o$ eac/ layer be$ore t/e %rotection timer times out+ it starts t/e

,3!2 timer+ and sto%s t/is timer a$ter it receives N3!2 CP9H1HNC4ND %rimitives be$ore t/e ,3!2

timer times out# ,/en it starts establis/in( u%lin6 dedicated c/annel @radio lin6 and con$i(ures R8C @R>!

R>)# A$ter RRC receives all t/e con$i(uration %rimitives o$ eac/ layer be$ore t/e %rotection timer times

out+ it starts measurement+ con$i(ures t/e ma7imum transmit %o*er o$ t/e 5+ and starts t/e 1R> D8AH

timer @*aitin( $or Node> to %er$orm u%lin6 sync/roni D8AH timer times out#

4n eac/ con$i(uration sta(e+ i$ RRC $ails to receive all t/e con$i(uration %rimitives o$ eac/ layer

be$ore t/e %rotection timer times out+ 5 *ill $ail to send out t/e RRC CONNC,4ON 1,5P

COMP8, messa(e# Mainly t/e %rimitives $or instance creation+ con$i(uration and release sent by R8C+

MAC and t/e %/ysical layer are involved# ,/e most common situation is t/at RRC $ails to receive N3!2

CP9H1HNC4ND %rimitives @indicatin( do*nlin6 sync/roni transmit %o*er is correct @observe t/rou(/ t/e radio lin6 setu% messa(e o$ 4ub# Note t/at

corres%ondin( o%tions in Dis%lay 1ettin( s/ould be set be$ore t/e in$ormation can be dis%layed#

Pac6et loss caused by abnormality in Node>

C/ec6 t/e relevant statistics in$ormation o$ demodulatin( D1P and decodin( D1P t/rou(/ t/e Node>

debu((in( console+ and identi$y */et/er Node> /as received data %ac6ets at t/e ne* u%lin6 DPDC9 or

*/et/er t/e %ac6ets received are all *ron( ones# For detailed o%eration+ re$er to t/e /el% document o$

Node> debu((in( console#

Pac6et loss on t/e 45> inter$ace

,/e RRC CONNC, 1,5P COMP8, messa(e may /ave been lost on t/e 45> inter$ace+ */ic/

can be analy ends+ t/rou(/ */ic/ t/e %roblem can be basically located in RNC+ Node> or transmission#

>ottom layer transmission is %robably im%lemented in t/e 4MA (rou% mode# 4n t/is case+ c/ec6 t/at t/e

4MA (rou% numbers at bot/ ends o$ eac/ ! in t/e 4MA (rou% are consistent#

4$ !s are in normal state+ c/ec6 */et/er AA82PA,9 o$ t/e A,M layer is in normal state+ and c/ec6

t/e state o$ PA,9 *it/ t/e MM8 command D1P AA82PA,9+ *it/ PA,9 4D+ NA1P address+ ! lin6

No# and P=C as t/e ma;or %oints to c/ec6#

!)"2! Con$idential Pa(e !" + ,otal 3-


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4$ t/ere is no abnormality in AA82PA,9+ c/ec6 t/e FP layer in user %lane o$ 45># Pac6et loss o$ FP

layer *ill %robably occur due to e7%iration time# For more about e7%iration time+ re$er to relevant

documents#

RNC receives t/e RRC CONNC, 1,5P COMP8, messa(e a$ter timeout#

,/e timer times out seconds a$ter RNC stats to *ait $or a messa(e# C/ec6 t/e timer settin( *it/ t/e

MM8 command 81, 1,A,,4MR# 4$ t/e con$i(uration is im%ro%er+ revise it *it/ MOD

1,A,,4MR# Con$irm t/e timeout event t/rou(/ t/e %rinted in$ormation o$ RNC 1P5 board# 4n

addition+ too muc/ 5 %rintin( or too muc/ Node> main control %rintin( may also cause t/is %roblem# 4n

t/is case+ disable t/e %rintin( $unction#

2#2#3 'ui%ment Analysis

Obtain t/e (eneral in$ormation about net*or6 e'ui%ment o%eration by vie*in( t/e alarm

in$ormation o$ RNC+ Node>+ 5M1C and 1G1N+ vie*in( e'ui%ment o%eration lo(s and runnin(

corres%ondin( MM8 command $or automatic test o$ t/e e'ui%ment# ,/e e'ui%ment analysis %rocess is

e'uivalent to a %rocess o$ %redia(nosis to e7clude any %roblem about e'ui%ment t/at may in$luence

access+ so as to avoid doin( useless *or6 in t/e conse'uent %roblem location %rocess and avoidin( *astin(

lots o$ /uman and material resources# As e'ui%ment analysis can *or6 t*ice t/e result *it/ /al$ t/e e$$ort

in t/e actual %roblem location %rocess+ so it is necessary at t/e early sta(e o$ %roblem location# For

instance+ detailed %rinted in$ormation o$ abnormality o$ RNC is available in t/e o%eration lo(#

,/e o%eration lo( o$ RNC is in t/e directory o$ >1C."00K8oadDataKFam8o(K# ,/e $ile name $ormat

is as $ollo*sB FN8OGyyyymmdd//nnss#lo(# FNB $rame No#+ t*odi(it numeral strin( yyyyB year mmB

mont/ ddB date //B /our nnB minute ssB second# ,/e abovementioned time re$ers to t/e moment */en

t/e lo( us u%loaded# 4$ t/ere is no $ile t/at is a$ter t/e abovementioned time+ t/e lo( bu$$er area is %robably

not $ull+ and lo( $iles can be u%loaded by means o$ t/e MM8 command $or u%loadin( lo( $iles# @58D

8OGF48B FN L $rame No##

Alarm in$ormation can be e7%orted# O%en t/e alarm *indo*+ select t/e alarm to be saved and save it

*it/ anot/er name or run t/e command e7% tbldata to e7%ort t/e alarm in$ormation to t/e directory

>1C."00?F,P# Alarms t/at a$$ect access mainly include transmission alarms o$ t/e carrier si(nalin(

@!?,!+ 1AA8+ NCP?CCP+ M,P3>+ internal 4PC and AA82PA,9 and e'ui%ment alarms @cloc6+ CP5+

D1P+ etc## 4$ suc/ alarms occur+ $ind out t/e causes and eliminate t/ese alarms t/orou(/ly#

Run t/e MM8 command ,1, 1H1 $or e'ui%ment automatic test# ,/e system can automatically

detect e'ui%ment $aults o$ t/e trans%ort layer and lin6 $ault o$ trans%ort si(nalin( layer# ,/e contents o$ t/e

sel$dia(nosis are as $ollo*sB board status and subsystem status dia(nosis board autotest results

dia(nosis board cloc6 state dia(nosis WM5?WFMR board tem%erature dia(nosis trans%ort layer lin6

dia(nosis *it/in?bet*een WR>1 $rames trans%ort layer lin6 dia(nosis bet*een WR>1 $rame and WR11

$rame D1P+ 9P4 and ,DM dia(nosis o$ WFMR board RFN status internal P=C con$i(uration# 4$ t/e sel$

!)"2! Con$idential Pa(e !- + ,otal 3-


20/39


dia(nosis $unction is success$ully enabled+ a$ter a certain %eriod o$ time+ t/e dia(nosis results *ill be

re%orted and saved in t/e te7t $ormat under t/e directory o$ >1C."00 installationK8OADDA,AK

WR>1FAD o$ t/e >AM# 4$ 8M, and >AM are se%arated+ 'uery t/e in$ormation t/rou(/ F,P Client o$

o%eration and maintenance system on t/e 8M,# ,/e namin( rule o$ t/e dia(nosis result $iles is $rame No#

FADR158, year mont/ date /our minute# For instance+ t/e dia(nosis result $ile

WR>10!FADR158,2002!!0!!0)-#,, means t/e te7t $ile o$ $ault dia(nosis $or WR>1 $rame !

re%orted at !0B)-+ November !+ 2002# No* ta6e t/e dia(nosis result analysis $or 1ubsystem 0 o$ 1P5

board o$ 1lot !0 in Frame 3 as an e7am%leB

>OARD 1P5!0 D4AGNO1 >G4N

Q1P5!0B@>oard nable

??>oard is normal

S

>oard 1el$,est Dia(nose

Q1P5!0 1ub1ystem0B@C/i% 1el$,est OT

Q1P5!0 1ub1ystem!B@C/i% 1el$,est OT

??>oard c/i% sel$test is normal

S

>oard Cloc6 1tatus Dia(nose

Q1P5!0 Cl6 1tatusB@Cloc6 "T OT

??Cloc6 status normal

S

CP5 5sa(e Dia(nose

Q1P5!0 C%u No0B @33E

Q1P5!0 C%u No!B @!3E

?? Current CP5 usa(e o$ t*o subsystems

S

4ntra ControlPlane 4PC 1tatus Dia(nose



21/39


Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@! +0B @Dest1ub1ystem Absent

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@3 +0B @OT

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@ +0B @Dest1ub1ystem Absent

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@- +0B @Dest1ub1ystem Absent

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@!3+0B @Dest1ub1ystem Absent

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@0 +0B @OT

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@!+0B @Dest1ub1ystem Absent

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@ +0B @OT

Q1rc1ub1ystem@!0+0 UJ Dest1ub1ystem@!0+!B @OT

??,/e 4PC c/annels bet*een 1P5 board to FMR+ 4 and M5 o$ t/is $rame is normal t/e reason

$or t/e abnormality is t/at t/e board is not %lu((ed

S

4nter 1P51P5 4PC 1tatus Dia(nose

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@! +!0+0B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@! +!0+!B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@) +!0+0B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@) +!0+!B@Dia(nose FailV

??,/e 4PC c/annels bet*een 1P5 o$ Frame 3 and 1P5s o$ Frame ! and Frame ) are not t/rou(/

because Frame ! and Frame ) are not con$i(ured#

S

4nter 1P59P5 4PC 1tatus Dia(nose

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +!+!B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +!+2B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +2+!B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +2+2B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +3+!B@Dia(nose FailV

!)"2! Con$idential Pa(e 2! + ,otal 3-


22/39


Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +3+2B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +)+!B@Dia(nose FailV

Q1rc1ub1ystem@3+!0+0 UJ Dest1ub1ystem@2 +)+2B@Dia(nose FailV

??Communication bet*een 1P5 o$ Frame 3 and 9P5 o$ Frame 2 is not available because 9P5 o$

Frame 2 is not in %osition#

S

,/e document o$ common met/ods $or Node> =!#3 e'ui%ment analysis /as not been out%utted till

no*+ so related contents are to be su%%lemented#

2#2#) Covera(e Analysis

Access di$$iculties caused by covera(e %roblems are $re'uently seen# Covera(e absence+ s/aded areaand border o$ t/e net*or6 are t/e areas */ere access $ailure occurs usually# Per$orm t/e %ilot covera(e test

on t/ose areas *it/ im%er$ect access success rate+ and record t/e distribution o$ R1CP and c?4o o$ t/e

%ilot c/annel *it/ drive test e'ui%ment ).A under t/e conditions o$ di$$erent services and di$$erent

loads# Furt/ermore+ because covera(e is closely related to ca%acity+ covera(e absence *ill %robably /a%%en

at cell border i$ t/e cell load increases# ,/ere$ore durin( t/e actual covera(e test+ select a /i(/load time

se(ment o$ a cell as t/e test time se(ment @re$er to tra$$ic statistics data+ or %er$orm do*nlin6 OCN1 test

*it/ simulated load in a time se(ment */en t/e user tra$$ic is lo*#

4$ covera(e absence e7ists in t/e test area+ consider t/e ma;or net*or6 en(ineerin( %arameters@a


23/39


Preamble4nitialPo*er /as in$luences on random access+ and t/e initial transmit %o*er o$ dedicated

c/annels /as in$luences on u%lin6 and do*nlin6 sync/roni debu((in( console# W/en establis/in( u%lin6 and do*nlin6 dedicated c/annels+

%ay attention to t/e settin( o$ t/e initial 14R tar(et value+ because t/ere is a delay o$ outer loo% %o*er

control com%ared *it/ inner loo% %o*er control+ and too lo* an initial 14R tar(et value *ill lead to lin6

outo$sync/roni and 5 by correctin( 14R tar(et

value# Currently+ t/e >8R tar(et value o$ si(nalin( is !E#

9ere is an e7am%le o$ 5 access $ailure a$ter covera(e restriction# As s/o*n in t/e dia(ram belo*+

call dro% occurs */en t/e code transmit %o*er o$ Node> and 5 u%lin6 transmit %o*er re'uested by

u%lin6 ,PC bot/ reac/ t/e ma7imum value+ */ic/ occurs at t/e cell border or in case o$ covera(e absence#

9o*ever+ a$ter call dro%+ 5 *ill conduct cell searc/ and residin(+ read t/e system broadcast in$ormation+

initiate random access and im%lement location u%date# As s/o*n belo*+ 5 cannot obtain t/e com%lete

in$ormation because o$ covera(e restriction+ and it is re%eatedly readin( t/e in$ormation *it/out bein( able

to (et accessed#



24/39


Figure + Access &ro'lem #aused 'y #o,erage Restriction

A$ter com%arin( t/e drive test results *it/ %lannin( results o$ t/e %ilot covera(e+ it is $ound t/at t/is

%osition is out o$ t/e %lannin( area# ,/ere$ore+ */en (ettin( into t/e covered area+ 5 %er$orms cell

residin(+ receives system in$ormation broadcast a(ain normally and initiate location u%date+ as s/o*n

belo*#

!)"2! Con$idential Pa(e 2) + ,otal 3-


25/39


Figure - .ormal Access &rocess

2#2#. Access Al(orit/m Parameter Analysis

Analy


26/39


e7am%le+ t/e %reamble %o*er ram% ste%+ t/e ma7imum %reamble retransmission times t/e sync/roniei;in( 4nstitute o$ 9ua*ei is a test 5+ its various %er$ormances are better t/an t/ose o$ NC# Durin(

trial system test %rocesses+ many %roblems a%%eared in NC 5# For e7am%le+ bad su%%ort to cell

reselectionB NC 5 usually (oes deadloc6ed */en in 4D8 status in /andover areas an internal

%arameter *it/in t/e 5 is im%ro%erly set @t/e W4NDOW 14 %arameter+ ori(inally set at 07"0+ no*

07FF in 9ua*ei net*or6+ */ic/ causes $ailure in receivin( t/e R> 1,5P COMP8, messa(e and

t/us access $ailure# 1uc/ di$$erences bet*een 5s /ave obvious in$luences on net*or6 access inde7

o%timi


27/39


WC!"A RN# Special Sub;ect Stu'4 ( #ilot Receivin& Stren&t Requirement Anal4sis un'er iven #o+er

Allocation Ratio) 'oc)

Ad;ustment recommendationB

Plan t/e net*or6 a%%ro%riately to reduce t/e dead s%ots o$ net*or6 covera(e# Consider ad;ustin( t/e

antenna as

o$ ad;acent cells+ 5s in t/e local cell and ad;acent cells+ etc# 4$ t/e u%lin6 and do*nlin6 inter$erence is too

stron( durin( t/e access %rocess+ t/e receivin( %arty may $ail to %er$orm si(nal demodulation+ and t/e

sendin( %arty may use u% t/e ma7imum %o*er#

,/e u%lin6 inter$erence is too stron(B Durin( t/e random access %rocess+ even i$ t/e %reamble %o*er

/as been increased to t/e ma7imum 5 transmit %o*er+ it is still unable to meet t/e re'uirement o$ Node>

demodulation+ resultin( in $ailure o$ random access %rocess# 4t is $ound $rom Node> debu((in( console

t/at R114 /as been al*ays /i(/ @/i(/er t/an 00d>m+ and u%lin6 >8R is also /i(/# 5%lin6 inter$erence

comes %robably $rom t/e outside# ,oo /eavy cell tra$$ic may also result in stron( u%lin6 inter$erence#

,oo stron( do*nlin6 inter$erenceB Durin( t/e random access %rocess+ t/e 5 is unable to demodulate

or *ron(ly demodulates t/e access indicator @A4 delivered by Node>+ or t/e do*nlin6 sync/roni


28/39


be close to t/e system %reset access t/res/old values# ,/e u%lin6 and do*nlin6 load $actors o$ various

services can be observed *it/ MM8 command81, C88CAC#

=ie* t/e RNC tra$$ic statistics data# Hou can $ind t/at t/e number o$ times o$ call $ailure caused by

con(estion is $ar /i(/er t/an t/e normal statistics values#

4$ t/ese t/ree conditions are met+ *e can be sure t/at t/e cause o$ 5 access $ailure is cell overload#

Call admission control @CAC al(orit/m is to $orecast t/e c/an(es on system load brou(/t by

admission o$ call access re'uest accordin( to t/e current load o$ t/e system and call access re'uest to ;ud(e

*/et/er t/e system can run normally *it/ ne* load conditions# 4$ t/e c/an(ed load /as not e7ceeded t/e

normal o%eration limit o$ t/e system+ t/is access re'uest *ill be %ermitted ot/er*ise+ t/e access re'uest

*ill be re;ected# ,/ere$ore+ t/e call admission control al(orit/m is based on load $orecast# For t/is reason+

our al(orit/m al*ays %er$orms load $orecast $irst+ and t/en ;ud(es */et/er t/e $orecast load value e7ceeds

t/e %reset system load t/res/old# 4$ $orecast does not e7ceed t/e %reset t/res/old+ t/e access *ill be

admitted ot/er*ise+ t/e access *ill be re;ected#


Allocate cell tra$$ic a%%ro%riately increase t/e ca%acity directly by addin( Node>s#

$./ Radio Parameter ettings

3#2#! ,oo 9i(/ 1ettin(s o$ :'ualmin and :r7levmin

4n t/is case+ 5 reads :'ualmin and :r7levmin $rom 14>3 durin( cell selection+ and identi$y

*/et/er t/e current cell is suitable to reside in by t/e 1 CriteriaB i$ t/e 1 Criteria is met+ t/is cell is

considered as a suitable cell $or 5+ and t/e 5 *ill reside in t/is cell+ and read ot/er system in$ormation

re'uired# ,/en 5 *ill initiate location re(istration %rocess# 4$ :'ualmin and :r7levmin settin(s are too

/i(/+ on one /and+ */en t/e 5 (oes too $ar $rom t/e Node> durin( t/e conversation+ 5 may $ail to

reside in t/e cell a$ter o$$/oo6# Po*er control can ensure t/at t/e lin6 remains connected */en 5 is

movin( a$ar+ and t/at 5 can %er$orm cell reselection a$ter o$$/oo6# 1ince t/e common %ilot c/annel

si(nal is already *ea6+ i$ :'ualmin and :r7levmin are set too /i(/+ 5 *ill /ardly succeed in cell

reselection# On t/e ot/er /and+ 5 initial access *ill become di$$icult+ and it can be seen $rom 5bac6(round o$ >ei;in( 4nstitute o$ 9ua*ei t/at t/e 5 cannot com%lete cell residin(#


1et %ro%er :'ualmin and :r7levmin values accordin( to actual conditions+ c/ec6 system set values

*it/ MM8 Command81, C8818R18+ and t/en modi$y t/em *it/MOD C8818R18#

3#2#2 4m%ro%er 1ettin(s o$ Access ,/res/old

Access t/res/old /erein re$ers to %reamble t/res/old o$ PRAC9#

!)"2! Con$idential Pa(e 2" + ,otal 3-


29/39


,/e %reamble t/res/old de$ines t/e PRAC9 %reamble test t/res/old+ and RNC in$orms Node> in

common transmission c/annel setu% si(nalin( on t/e 45> inter$ace @de$ault con$i(uration is 32+ e'uivalent

to 20d># ,/is %reamble can be is ac6no*led(ed only */en t/e ratio bet*een t/e %reamble %o*er and t/e

noise level received durin( t/e %reamble cycle is lar(er t/an t/is t/res/old# 4$ t/e %arameter settin( is too

small+ t/e random access %reamble si(nal *ill be ;ud(ed *ron(ly and $alse alarms *ill increase+ */ic/ *ill

lo*er t/e demodulation 'uality o$ random access+ es%ecially under t/e condition o$ lac6 o$ demodulation

resources# False alarms can also lead to invalid data transmission o$ do*nlin6 A4C9+ */ic/ *astes

do*nlin6 %o*er and increases t/e do*nlin6 inter$erence# False alarms %robability can be vie*ed at

debu((in( console# ,/e criterion is one t/ousandt/+ and any value /i(/ t/an t/is $i(ure means t/at t/e

$alse alarm %robability is too /i(/ i$ t/e %reamble t/res/old settin( is too lar(e+ t/e access di$$iculty *ill

increase+ and t/e %reamble si(nal ca%ture %robability *ill be reduced i$ t/e 5 u%lin6 transmit %o*er is

too /i(/+ t/e PRAC9 u%lin6 inter$erence *ill increase# ,/is %arameter decides t/e demodulation 'uality o$

random access and subscriber access success rate+ and /as relations *it/ access distance @access c/annel

covera(e radius X 2+ and di$$erent Node> con$i(urations @$ourantenna diversity mode and O,1R mode#

Processin( recommendationB

Ad;ust access t/res/old value a%%ro%riately+ and de$ault values o$ current system areB %reamble

t/res/oldB 32+ corres%ondin( to 20#0d>#

3#2#3 4na%%ro%riate 1ettin( o$ Preamble Po*er Ram% 1te% and Retransmission ,imes

5 can obtain ma7imum %reamble retransmission times and %reamble %o*er ram% ste% by receivin(

14>3# 4$ 5 /as not received A4 at %reset time slot a$ter sendin( out Preamble+ t/e %reamble %o*er *ill be

increased by one ste%+ and t/e retransmission counter *ill be reduced by !+ until t/e counter value becomes

0+ */en retransmission *ill be sto%%ed#

1ettin( o$ %reamble %o*er ram% ste% /as in$luence on t/e increasin( s%eed o$ access %reamble

transmit %o*er# 4$ it is set too small+ t/e number o$ times o$ subscriber access attem%ts *ill increase+ */ic/

increases t/e %robability o$ %reamble collision i$ it is set too lar(e+ t/e access %reamble %o*er value may

(reatly e7ceeds t/e value re'uired+ */ic/ increases inter$erence to t/e system#

Generally+ i$ t/e ste% remains unc/an(ed+ t/e lar(er t/e PreambleRetransMa7 value is+ t/e /i(/er

t/e success rate o$ random access *ill be+ but t/e PRAC9 load *ill increase conse'uently# 4n cells o$ /i(/

tra$$ic+ i$ t/e ma7imum retransmission times value is too lar(e+ radio c/annel overload and con(estion *ill

be caused+ and t/e %robability o$ 5 access collision *ill be increased (reatly+ */ic/ *ill reduce call

com%letion rate and radio resource utili


30/39


,/ese t*o %arameters ;ointly control t/e 5 access %reamble ram% %rocess# W/en settin( t/ese

%arameters+ %ay attention to reduction o$ system u%lin6 inter$erence+ im%rovement o$ access success rate

and reduction access delay# ,/ere$ore+ it is necessary to set a%%ro%riate values accordin( to t/e actual

situation#

3#2#) 4na%%ro%riate 1ettin( o$ Ad;acent Cells

,/e %ilot measurement in$ormation about t/e current cell and t/e ad;acent cells attac/ed to 5 can

be seen $rom t/e RRC CONNC,4ON R:51, messa(e# 1uc/ measurements are all conducted by 5

at cell selection# 4$ t/ere are too many ad;acent cells o$ t/e main cell in system messa(e broadcast+ ,/e 5

*ill need a lon( time to measure t/e %ilot si(nal 'uality o$ all t/e ad;acent cells+ and t/is *ill in$luence

subscriber access s%eed# 1o an im%ortant tas6 o$ net*or6 o%timi


31/39


Do*nlin6 sync/roni


32/39


4ncrease t/e %o*er allocation ratio $or t/e common c/annel a%%ro%riately#

3#2# Over8o* 4nitial Po*er o$ 5%lin6 and Do*nlin6 Dedicated C/annel

P/enomenonB u% lin6 or do*n lin6 sync/roni# CP4C9c?4o

is t/e c?4o o$ common %ilot c/annel measured by 5+ */ic/ is re%orted to 5,RAN t/rou(/ RAC9+ and

its de$ault value is !"d># ,/is value can be revised by MM8 command 1, FRC# P%c%ic/ is t/e transmit

%o*er o$ common %ilot c/annel#

Calculation $ormula o$ u%lin6 initial transmit %o*erB

DPCC94nitial%o*er L DPCC9Po*ero$$set CP4C9R1CP

W/ere+ CP4C9R1CP is measured by t/e 5+ and DPCC9Po*ero$$set is sent by RNC to t/e 5

t/rou(/ t/e RRC CONNC, 1,5P messa(e#


4ncrease t/e u%lin6 and do*nlin6 initial transmit %o*ers a%%ro%riately# 4nner loo% %o*er control can

decrease t/e over/i(/ %o*er ra%idly a$ter success u%lin6do*nlin6 sync/roni


33/39


$.$ 45ui&ment Reasons

3#3#! 4nsu$$icient RAN Device >oard 1ources

P/enomenonB ,/e re'uest $or a certain system source $ails at service setu%+ */ic/ can be seen only

$rom t/e internal messa(e $lo* or serial %ort out%ut# 4n ty%ical cases+ D1P is not available+ and RNC needs

to re'uest $or 82 instance source @D1P at RRC lin6 setu%# 4$ t/e number o$ FMR boards is insu$$icient or

a certain D1P is abnormal+ t/e resource re'uest is li6ely to $ail#

Cause o$ t/is %roblem is t/e insu$$icient board sources or board $ault#


Add or re%lace boards#

3#3#2 Abnormality o$ 'ui%ment Cloc6

Abnormality o$ cloc6 *ill lead to one o$ t/e most common %roblemsB e7%iration time %roblem

@massive %oc6et loss on t/e 45> inter$ace# Durin( t/e access %rocess+ t/e %/enomenon is t/at a certain air

inter$ace messa(e is lost */en bein( trans$erred t/rou(/ t/e 45> inter$ace# ,/is %/enomenon can be seen

on t/e Node> debu((in( console or t/rou(/ net*or6 /a*6 on t/e 45> inter$ace#

Cloc6 o$ net*or6 e'ui%ment /as (reat in$luence on sync/roni cloc6

sync/roni


34/39


is+ t/e e7%iration time %roblem+ */ic/ can be seen on t/e 45> inter$ace *it/ net*or6 /a*6+ and massive

%oc6et loss alarms can be seen in t/e serial %ort %rinted in$ormation o$ e'ui%ment#

4n an AA82PA,9+ distribution o$ 2. C4Ds is admitted+ eac/ C4D means an AA82 C9ANNA8+ and

eac/ AA82 84NT corres%onds to an FP# For instanceB a voice service+ or a DC9+ corres%onds to an AA82C9ANNA8 identi$ied by a C4D# For an AMR voice service+ t*o AA82 C/annels *ill be establis/ed+ one

o$ */ic/ bears si(nalin(+ and t/e ot/er bears tra$$ic# C4Ds are dynamically allocated+ and t/e total

band*idt/ o$ all AA82 C/annels must not e7ceed band*idt/ o$ AA82 PA,9#

,/e 45> inter$ace bears t/e si(nalin( %lane+ user %lane and mana(ement %lane# ,/e si(nalin( %lane

includes NCP+ CCP and A8CAP t/e %lane includes AA82 PA,9+ and t/e mana(ement %lane is t/e 4POA

o%eration and maintenance %at/ o$ t/e Node># ,/ere is no %roblem *it/ t/e ca%acity o$ si(nalin( and

mana(ement %lane in actual a%%lications+ and t/e bottlenec6 is usually on AA82 PA,9# Micro %at/s are

establis/ed dynamically on AA82 PA,9 in eac/ callin( %rocess# 4$ t/e available band*idt/ o$ AA82

PA,9 @band*idt/ ma%%ed to ! is insu$$icient+ access $ailure *ill occur#

,/e $ollo*in( %ara(ra%/s *ill describe t/e band*idt/ allocation on AA82 PA,9+ *it/ a .)6 data

service as an e7am%le# On t/e 45> inter$ace+ $or a .)6 service+ besides its o*n service tra$$ic+ t/e

over/eads also include FP over/ead+ AA82 over/ead+ A,M over/ead and ! over/ead# Accordin( to t/e

calculation+ t/e s%eci$ic over/ead %ro%ortion is as listed in ,able #

Ta'le 2 /,erhead &roportion for $ach Layer on )!0 )nterface

1ervice FP AA82 A,M !

3#)T si(nalin( 2)E !2#2E -#)E .#2E

.)T service )E "#3E -#)E .#2E

Data $lo* @.)T data service

.)Tb%s ? @!FP over/ead ? @!A,M over/ead ?@!AA82 over/ead ? @!! over/ead 3#)Tb%s?

@!FP over/ead ? @!A,M over/ead ?@!AA82 over/ead ? @!! over/ead .)Tb%s ? -.E ? -0#.E?

-!#E ? -3#E 3#)Tb%s? .E ? -0#.E? "#"E ? -3#E-!#.0Tb%s

4$ t/e available band*idt/ resource o$ ! is smaller t/an -!#.0Tb%s+ service can not access normally#


C/ec6 t/e 45> inter$ace band*idt/ and increase transmission resources#

3#)#2 PA,9 4D and N1AP Address Con$i(uration rror o$ AA82PA,9

,/e %/enomenon is also lin6 setu% $ailure in t/e trans%ort layer+ and t/e reason is t/at t/e %eer A,M

node can not be reac/ed# An AA82PA,9 is identi$ied uni'uely *it/ node number PA,9 4D# ,/e N1AP

address is t/e terminal address $or AA82 connection setu%# 5M1CKNode>KDRNC connected *it/ RNC all

/ave A,M addresses+ */ic/ are destination addresses o$ AA82 connections# Durin( AA82 route

con$i(uration+ t/ese destination addresses must be consistent by ne(otiation#

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4n addition+ t/ese t*o %arameters are s%ecially mentioned because t/e %roblem is some*/at

concealed+ not easily $ound *it/out service access+ and once t/ere is service access+ it *ill a%%ear and

ma6e troubles#


C/ec6 ne(otiated %arameters by t/e MM8 commands81, AA82PA,9andD1P AA82PA,9#

4$ t/e %arameters o$ bot/ sides are not consistent+ remove t/e %at/ *it/ t/e related MM8 command and

t/en create an AA82PA,9#

3#)#3 4nconsistent Number o$ AA82PA,9s across 45?45> 4nter$ace

AA82PA,9 is used to bear user %lane data+ t/e %rocesses o$ data transmission t/rou(/ t/e 45?45>

inter$aces are all AA82 lin6 creation %rocesses initiated automatically by RNC# W/en multi%le

AA82PA,9s e7ist on t/e inter$aces+ in order to (uarantee evenly distribution o$ user %lane load+ RNCselects t/e AA82PA,9s alternatively# 4$ t/e number o$ AA82PA,9s is bi((er t/an t/at at t/e %eer end+ t/e

access %rocess may $ail+ in a certain %ro%ortion# For instance+ i$ $our %at/s are con$i(ured at t/e RNC side+

o$ */ic/ t/e PA,9 4Ds are !+ 2+ 3 and )+ and t*o %at/s are con$i(ured at t/e M1C side+ o$ */ic/ t/e PA,9

4Ds are ! and 2+ */en RNC selects %at/s 3 and ) $or lin6 creation+ access $ailure *ill occur+ and t/e $ailure

%ro%ortion is 0E# 4$ t/e number o$ RNC AA82PA,9s is smaller t/an t/at at t/e %eer end+ suc/ a %roblem

*ill not occur#

4$ $ailure and success occur alternatively durin( t/e access %rocess+ and a $i7ed $ailure ratio e7ists+

t/e reason mi(/t by t/is ty%e o$ errors#


C/ec6 ne(otiated %arameters *it/ t/e MM8 Commands 81, AA82PA,9 and D1P

AA82PA,9+ and remove t/e redundant AA82PA,9s on t/e RNC#

,/ere are many similar data con$i(uration errors+ suc/ as inconsistent si(nalin( %oint codes o$

M,P3> layer+ etc#+ */ic/ *ill not be listed /ere one by one# 4t is easy to locate suc/ errors+ and all *e need

are si(nalin( $lo* and MM8 commands#

$.7 'ther Reasons

3##! 4nsu$$icient 5 Access Class @AC

For t/e o%erators+ t/ere are t*o *ays $or restrictin( an access cell# One is s%eci$yin( t/e state o$ t/is

cell @reserved $or o%erator due to control and t/e ot/er is admission control+ denyin( t/e access o$

subscribers in a certain AC ran(e# 4n order to avoid c/annel overload under t/e critical condition in

o%eration+ all 5s /ave been randomly assi(ned *it/ AC 0 t/rou(/ AC -# Furt/ermore+ 5s can also be

assi(ned *it/ one or more s%ecial access classes @AC !! t/rou(/ AC !+ */ic/ belon(s to s%eci$ied

su%erior subscribers# From t/e %oint o$ vie* o$ subscribers+ t/e access is denied because o$ system load#



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9o*ever+ access is allo*ed $or subscribers *it/ s%ecial ACs# ,/e AC o$ a subscriber is stored in t/e

514M#


=ie* t/e access control in$ormation in t/e cell system in$ormation and ad;ust t/e cell access control

%olicy#

3##2 4nconsistent 1ecurity Data o$ 5+ RNC and CN

,/e security %rocesses involved in 5 access %rocessB aut/entication @NA1 layer and security mode

%rocess @A1 layer# ,/e detailed $lo* is s/o*n in Fi(ure !0#

!$ #.R.#

1RR# S$T!& #/*&L$T$

2).)T DT

3 Authenticaton &rocess

S$#!R)T */D$ #/**A.D

"S$#!R)T */D$ #/**A.D

%S$#!R)T */D$ #/*&L$T$

(S$#!R)T */D$ #/*&L$T$

Figure 1 !$ Authentication and Security *ode &rocess

!!4n t/e RRC 1,5P COMP8, messa(e+ 5 sends t/e 1,AR, value+ and t/e 5 encry%tion

ability @5A and 5 inte(rity %rotection ability @54A in$ormation to RNC and simultaneously in$orms

RNC about t/e G1M Classmar6 2 and Classmar6 3 in$ormation accordin( to t/e re'uirement o$ RRC

setu% messa(e#

2# 5 carries t/e user identity and t/e T14 @Tey 1et 4denti$ier in t/e initial directtransmission

messa(e @location u%date re'uest+ CM service re'uest+ location are u%date re'uest+ attac/ re'uest and

%a(in( res%onse to in$orm CN#

3# CN decides on t/e 4T?CT to be used accordin( to t/e T14# 4t %er$orms aut/entication+ and

in$orms t/e 5 about t/e ne* 4T?CT# Mean*/ile+ CN decides on t/e 54As and 5As %ermitted $or use#

)# CN sends t/e RANAP messa(e 1C5R4,H MOD COMMAND to RANAP to start encry%tion

and inte(rity %rotection#

# RNC selects an al(orit/m su%%ortable by 5 amon( t/e al(orit/ms %rovided by CN+ and

(enerates a random number FR19 re'uired by t/e inte(rity %rotection al(orit/m# RNC carries out

;ud(ment accordin( to t/e ability re%orted by 5B i$ t/e 5 ability cannot su%%ort t/ese al(orit/ms+ RNC

!)"2! Con$idential Pa(e 3. + ,otal 3-


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sends t/e 1C5R4,H MOD R&C, messa(e to CN in res%onse+ and t/en RNC tri((ers t/e release

$lo*#

RNC sends an RRC messa(e 1C5R4,H MOD COMMAND to t/e 5# ,/is messa(e includes 5

inte(rity %rotection ability+ G1M encry%tion ability @o%tional+ i$ received in t/e RRC setu% com%letemessa(e+ 54A and FR19# RNC %er$orms inte(rity %rotection o$ t/is messa(e#

.# A$ter 5 receives RRC messa(e 1C5R4,H MOD COMMAND+ it com%ares t/e 5 ability

in$ormation in t/e messa(e# 4$ it is t/e same *it/ t/e 5 ability in$ormation saved locally+ it *ill be

deemed le(al# 5 %er$orms inte(rity %rotection c/ec6 on t/e 1C5R4,H MOD COMMAND messa(e

received# 4$ it is correct+ 5 sends an RRC messa(e 1C5R4,H MOD COMP8, to RNC# ,/is

messa(e also re'uires inte(rity %rotection#

4$ t/e security mode con$i(uration $ails+ 5 sends t/e 1C5R4,H MOD FA485R messa(e to

RNC#

# A$ter receivin( t/e success res%onse messa(e $rom 5+ RNC %er$orms inte(rity %rotection

c/ec6# 4$ it is correct+ RNC sends an RNCAP res%onse messa(e 1C5R4,H MOD COMP8, to CN+

*/ic/ includes t/e al(orit/m selected# ,/en t/e $lo* ends#

4$ RNC receives t/e 1C5R4,H MOD F8485R messa(e+ or i$ t/e security mode con$i(uration

$ails+ RNC sends t/e 1C5R4,H MOD R&C, messa(e to CN+ and t/en tri((ers RRC release#

Currently+ all t/e security %rocesses o$ e'ui%ment are %rovided *it/ s*itc/es# 4$ t/e su%%ort o$

aut/entication encry%tion by 5 and net*or6 side is not consistent+ 5 access *ill surely $ail# ,/is

%roblem can be identi$ied t/rou(/ t/e RNC and CN messa(es#


Ad;ust t/e security %arameter con$i(uration o$ t/e 5 so t/at it can consistent *it/ t/e net*or6 side#

3##3 5 not Re(istered in 98R

4$ t/e 5 is not re(istered in t/e 98R+ 5 location u%date *ill $ail+ and a location u%date re;ect

messa(e can be $ound on t/e 5M1C maintenance console+ *it/ t/e cause value bein( imsi un6no*n in

/lr# 4n t/is case+ c/ec6 t/e 5 subscri%tion in$ormation in t/e 98R# 9o*ever+ t/e %robability o$ t/is

situation is very lo*#


Add t/e 5 subscri%tion in$ormation in t/e 98R#

6 'utstanding 8ssues

!# For t/e radio %arameters t/at a$$ect access+ t/e in$luences are only 'ualitatively analy


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2# >ecause t/ere are many core net*or6 devices+ t/e inter$ace %rotocols are very com%licated+ and

t/ere are di$$erences bet*een R-- and R) devices on t/e net*or6 @C1 is re%laced *it/ M1C server and

MGW+ t/is document only %resents t/e most common causes t/at a$$ect access+ so t/is %art o$ contents are

to be su%%lemented#

!)"2! Con$idential Pa(e 3" + ,otal 3-


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8ists o$ Re$erences"

Q! #$PP R%&&& 2'()*+,*) 22/&

Q2 C0*1, WCDMA RNP S3*4,56 T*40176789 R*)*5+40 K*9 S,8156,18 P+74*)) A1569),)

A44*)) P+74*))2#/:

Q3 ;07< =,1>,* WCDMA RNP S9)?*@ P5+5@*?*+ C71,8

WCDMA RNO Access Problem Analysis Guidance

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