# How is the CSSR formula ?
CSSR_w/o_block CSSR_w/o_bl ock = ImmAss SR x SSS SR
ImmAss SR = NSUCCHP NSUCCHPC(SMTCSD) ATIMASCA
ImAss Phase
SSS Proc Phase
SSS Proc SR = NSUC NSUCCHPC(SMTCSD)
TCH A Assignment ssignment Phase TCH Ass SR = TASSSUCC(F,H)+ +SUOISHDO(DR)
Proc SR x Ass TCH
C(APSD,CRSD,ECSD,OCSD)(APSD,CRSD,ECSD,OCSD)-NSUCCHPC(SMTCSD)
TASSAT (F,H) CHPC(APSD,CRSD,ECSD,OCSD)-
TASSFAIL(NRF, TASSFAIL(NRF,NRH)+SINTHINT(DR)+SUINBHDO(DR) NRH)+SINTHINT(DR)+SUINBHDO(DR) TASSAT (F,H)
Analysis # What factor can influence within this phase ?
Phase I : ATIMASCA Loss probabl!" : a# $o S%CCH a&alabl - H)h (+mber o, re - Lack o, S%CCH re - .&er *le co&era) b# Tra(smsso( probl - ,lcker !ra(smss - (o! L.S !ra(sms - +((ecessar" cabl - problems o( C.4 c# H6 problem 7 wro - h)h 0S6R - broke( mo*+le - +(!)h! co((ec!or - broke( cable/,ee* - ,abrca!o( ,a+l!" : - cell (&erso( : a( *# Ra*o I(!er,ace pro - ,re+e(c" (!er,er - +(bala(ce UL 7 % - +((ecessar" *b s
Phase II : SUIMASCA Loss probabl!" : a# Tra(smsso( probl - see po(! b o( ph b# ACH o&erloa* - see s!a!s!c meas - , !he *,,ere(ces c# Ra*o I(!er,ace pro MS m)h! be *+e !o - see po(! * o( ph *# H6 problem 7 wro - see po(! c o( ph
Action
SUIMASCA -' S%CCH a!!emp! mee!() blocke* +es! o+rces
em - Abs (!er,ace -' messa)es loss CH$A01 CH$A23 be!wee( 4TS a(* 4SC ( o( obs!acle3 -' wro() !ra(smsso( pla((() () o( %%5 pa(el A/C.SA mo*+le ) (s!alla!o( o( 4TS -' ba* process()/,al+re1 +(-rece&e*/se(! o, messa)es !owar* 4TS/MS
er 8 h)h loss 4TS ma(boar*1 mo*+le slo! e((a1 ,ee*er1 backpla(e1 semr)*1 wro() H6 *b crea!o( lem -' messa)es loss be!wee( MS a(* 4TS e(ce L *+e !o mproper co&era)e o&ershoo! or lack o, co&era)e31 co(!o+r ,ac!or e!!()
a# S%CCH c - a**() - more sel se! R?L - re*+ce ! b# Ra*o I(! - ,re+e( - hopp() - power c - (o o&er - a(!e((a c# H6 probl - cha()( - ,x a(" *# Tra(sms - !ra(sm - ,x a(" !
$SUCCHPC em - Abs (!er,ace -' messa)es loss IMASS1 9STI$3 be!wee( 4TS a(* 4SC se I expla(a!o( : *,,ere(ce be!wee( TACC4PR. ;3 - $ACSUCPR;3 < mea(s !here are ACH o&erloa* lem -' messa)es IMASS1 SA4M1 CMSR93 loss be!wee( MS a(* 4TS 8 (o SA4M se(! !o 4TS b" MS +se* >pha(!om> RACH whe( se(* CH$R9 se I expla(a!o( ) (s!alla!o( o( 4TS -' ba* process()/,al+re1 +(-rece&e*/se(! o, messa)es !owar* 4TS/MS se I expla(a!o(
a# Sol&() A - a**() b b# Ra*o I(! - see po( c# H6 probl - see po( *# Tra(sms - see po(
pac!" o&erha(*l() m)h! be *o(e b" : %CCH TS w!h( TR? ec!&e o( ,l!er() MS ,or access() (e!work =' o(l" MS w!h )oo* UL le&el ca( access !he cell a(* )e! RACH 90AMI1 RACH4T3 he o&er3 co&era)e b" !l!() a*@+s!me(! r,ace +al!" mpro&eme(! : " re!+(e op!ma!o( hop mo*e1 hop ac!&a!o(1 HS$1 mao1 mall ls!s - check ! all3 - ,or *e*ca!e* mo*e (!rol mecha(sm !hreshol*1 s!ep se3 - ,or *e*ca!e* mo*e co&era)e ,or pre&e(!() (!er,er() w!h o!hers =' *o(e b" co&era)e a*@+s!me(! op!ma!o( a(! !"pe w!h proper beamw*!h1 a(! he)h!1 am+!h1 !l!3 m 7 wro() (s!alla!o( ,x() : a(" broke( mo*+le/e+pme(! ro() (s!alla!o( o( problem o&erha(*l() : so( repla( b" T$P , (o L.S3 b" a(!e((a Bw op!ma!o( he)h!31 !ra(smsso( re-ro+!e a(smsso( cabl()/co((ec!o( problem a(* mo*+le ,al+re
CH o&erloa* b" : lock ACH reser&e* =' se! $4L2ACR1 b+! m+s! co(s*er PCH reser&e* re*+c() mpac! b" (creas() !hs ACH capac!" r,ace +al!" mpro&eme(! : ! b o( expla(a!o( abo&e m 7 wro() (s!alla!o( ,x() : ! c o( expla(a!o( abo&e o( problem o&erha(*l() : ! * o( expla(a!o( abo&e
# What kind of process (procedures) occurred within this phase ?
- SSS Procedre P!"se s#"r# $rom C - SDCCH "re "re"d seed '#!& # - M"& SSS rocedre e.e&#s "re rocedres* - From 4SS po(! o, &ew, oss "&"
A#!e&#c"#o& Process
C!er&% Process
# How can the SDCCH connection ecome drop ?
>!"# m" 0e #!e mos# dro re"so& c"& 0e /&o'& $rom mesreme&# co&#er NRFLSDCC @1- ? Co&#er ) 2 , 1 ( C C D S L R F N
S0 Co&#er 1 3 2 7 9 : ; <
Descr#o& T344 e5red &soc#ed DM reso&se, m# $r"me es#"0s!ed s#"#e se6e&ce error T8MSRFPCI e5red ds#"&ce m# e5ceeded !"&do.er "ccess $"re r"do &/ $"re remo#e #r"&scoder $"re &sec$ed (o#!ers)
>!e& BTS !"s se&# " "er 3 "c/&o'ed%em
MS !"s se&# " Um "e s#"#e BTS !"s de#ec#ed rre% T8MSRFPCL s &o# "d MS-BTS ds#"&ce e5ce EJCDIST F"re o& HO SDCCHH>I&s#""#o&) R"do Pro0ems (&#er$e TRACTRAU mode $ TTRAU)
MS R9 mess"%e se&# $rom BSC #o'"rds MSC, "&d s#o "$#er rece# o$ ASS R9* !s !"se* r$ormed dr&% #!s !"se, #!"# "re "#!e&#c"#o&, c!er&%, IMEI c!ec/, TMSI re-"oc"#o&, se# mess"%e, "&d d%# #r"&s"#o& ss c"& 0e %o# $rom S%CCH *rop co+(!er $RL5S%CC_-D3
IMEI C!ec/ TMSI Re"oc"#o& Procedre
Se# Mess"%e D%# Tr"&s"#o& Procedre
er 3 mess"%e & "c/&o'ed%e mode (#!"# s I ,rame mess"%e ? ASS CM%3 N344+1 #mes #o #!e MS '#!o# rece.&% &# $rom MS (re"so&s ? "& r"do ro0ems m" e5s#) &# T344 #mer e5red, #!e& #!e co&&ec#o&s "re droed*
r 3 (LAPDm) mess"%e DM (Mode) #o #!e BTS '!e #!e BTS-MS comm&c"#o& s & m#e $r"me s#"0s!ed "r#es & #!e Um "er 3 (LAPDm) $o' co&#ro $&c#o&s ('ro&% mess"%e se6e&ce) seds &"c/&o'ed%ed mode s#"0e o& d"#"0"se ds #!e #!res!od SDCCH G C"ses ? R"do Pro0ems (&#er$ere&ce, co.er"%e, e&ce, co.er"%e, H>I&s#""#o&) "re, COBACU $"re, 'ro&% DB se##&% (TTRAU T< , TTRAU T14, TTRAU = TSNC = T!s se##&% s $or e&sr&% #!"# " s%&"&% $"
re (T< "&d T14) s de#ec#ed 0e$ore #r"&scoder $"re (TSNC "&d
# How is this phase ?
- TCH Ass%&me&# P - BSS Co&#er s#"r# - Ac#" TCH Boc/ formula
- T!ere s s# oss r - A& TCH Ass%&me
# !ASS"A$ causes ? Co&#er
L I A F ) S 4 S 2 , A 1 T (
S0 Co&#er $or CHAN TPE Descr#o& TCHF TCHH : 11 R"do I&#er$"ce Mess"%e F"re ; < 14
13 12 17 19
R"do I&#er$"ce F"re - re.erso& #o od c!"&&e No r"do resorce ".""0e Drec#ed Re#r A O#!er C"se
Co&#ed "s TCH Ass%&m Form" HCPT - see s!e#
TASSFAIL de #o R"do I&#er$"ce Mess"%e F"re
ASS CM% m - R"do I&#er$ - &&ecess"r
TASSFAIL de #o R"do I&#er$"ce F"re - re.erso& #o od c!"&&e
SA4M mess - R"do I&#er$ - &&ecess"r
%rec!e* Re!r - R"do I&#er$"
TASSFAIL de #o Drec#ed Re#r
>!e& %
!"se s#"r# "$#er rece.&% "ss%&me&# re6es# ASS R93 mess"%e o& BSC $rom MSC, "&d s#o "$#er "ss%&me&# come#e AS rom TASSATT "&d e&d 0 TASSSUCC &% &$e&ce #!s !"se, 4UT o& PI Form" HCPT $or CSSR, TCH 0oc/&% s excl+*e* $rom TCH "ss%&me&# $"re, 0# co o0"0# o& S%CCH %rop w!h T;<< expr" reaso( '#!& #!s !"se = c!ec/ $ "& ra*o problem '!c! c"se oss o$ ASS C &# F"re ' &creme&# TASS5AIL co&#er & BSC
&# Sccess o& PI CSSR formula
ess"%e s os#, m" 0e c"sed 0 ? "ce ro0em ? I&#er$ere&ce, Co.er"%e, H> F"re >ro&% I&s#""#o& T< se##&%
%e s os# '!e s&% FACCH, "ss%&me&# TCH $" "&d back !o S%CCH , m" 0e c"sed 0 ? "ce ro0em ? I&#er$ere&ce, Co.er"%e, H> F"re >ro&% I&s#""#o& T14 se##&%
H. ACC9SS mess"%e s os # '!e s&% FACCH, "ss%&me&# TCH $" "&d back !o S%CCH o& ol* cell , m" 0e c"sed 0 ? ce ro0em ? I&#er$ere&ce, Co.er"%e, H> F"re >ro&% I&s#""#o&
rec!e* Re!r" HO s er$ormed, TASSFAIL() co&#er ' 0e &creme&#ed
C.M3 mess"%e se&d&% #ed "s TCH Ass%&me&# Sccess - see o& s!ee# MD mess"%e
D% &arameter Related DB P"r"me#er
RJLEKAMI
RACHBT
NBLACR
T344
O0ec#
M&mm rece.ed e.e "# #!e MS re6red $or "ccess #o #!e &e#'or/
BTS
I&cre"se = Lo' UL e.e c"& "ccess RACH, more "##em# SDCCH, ess HO $" oss0# de #o FACCH reec#ed* Decre"se = O& %ood UL e.e c"& "ccess RACH, ess "##em# SDCCH, more HO $" oss0# de #o FACCH T!res!od $or #!e s%&" e.e o& RACH reec#ed*
BTS
Sec$es #!e &m0er o$ CCCH 0oc/s #o 0e reser.ed & CCCH TS $or ACH G I&cre"se = Add CCCH 0oc/s #o 0e reser.ed $or ACH, MAINBCCH ro.des CCCH 0oc/s decre"se 0oc/es #o 0e reser.ed $or PCH* (s!"red 0e#'ee& PCH "&d ACH) Decre"se = .c" .ers" $r om s#"#eme&# "0o.e*
BTS
LAPDm #mer 344 G de#erm&es #!e '"#&% #me $or " "er 3 $r"me "c/&o'ed%eme&#
S!od 0e "##e&ded #!"# #!s #mer se##&% c"& mc! redce dro c" s%&"&% co&ec#o&, 0# c"& "so de.er &o& re"s#c m"%e o$ #!e "c#" r"do &#er$"ce 6"# (ess dro 0# oor 6"#)* So &eed roer "ds#me&# "s #r"de o$$
To e&"0e ds"0e &#erce SDCCH HO
Se# Tre = "c#."#e &#erce SDCCH HO, more SDCCH s"%e, more oss0# o& SDCCH $"dro* Se# FALSE = ds"0&% &#erce SDCCH HO, ess SDCCH s"%e, ess oss0# o& SDCCH $"dro
To e&"0e ds"0e &#r"ce SDCCH HO
Se# Tre = "c#."#e &#erce SDCCH HO, more SDCCH s"%e, more oss0# o& SDCCH $"dro* Se# FALSE = ds"0&% &#erce SDCCH HO, ess SDCCH s"%e, ess oss0# o& SDCCH $"dro
BT S
To e&"0e ds"0e &#erBSC SDCCH HO
Se# Tre = "c#."#e &#erce SDCCH HO, more SDCCH s"%e, more oss0# o& SDCCH $"dro* Se# FALSE = ds"0&% &#erce SDCCH HO, ess SDCCH s"%e, ess oss0# o& SDCCH $"dro
BTS
Tmer ser.so& s#"r# $rom se&d&% UL TRAU $r"me "&d s#o '!e& $rs# DL TRAU $r"me rece.ed 0 BTS
Ms# se# #o roer ."e G Ms# $oo' #!e re ? TTRAU T<, TTRAU T14, TTRAU = TSNC $or e&sr&% s%&"&% $"re s de#ec#ed 0e$ore #r"&scoder $"re
IRACHOSDCC BTS
TTRAU
TSNC
T14
K"e Se##&% Tr"de O$$
BTS
IERCHOSDCC BTS
EISDCCHHO
Descr#o&
BTS G TRAU
BSC
I&cre"se = Ide co.er"%e s!r&/&%, ess "##em# SDCCH Decre"se = Ide co.er"%e e&"r%eme&#, more "##em# SDCCH
Tmer ser.so& s#"r# o$ TRAU $r"me Ms# 0e se# #o roer ."e G Ms# $oo' #!e re ? TSNC = !"&d&%* S#"r# '!e& 2 DL TRAU $r"me TTRAU G TSNC se##&% & BTS o0ec# ms# 0e s"me '#! !".e&# correc# rece.ed, "&d rese# TSNC se##&% & TRAU o0ec# '!e& correc# $r"me s rece.ed "%"&* Tme #o re#r& "ss%&me&# come#e (ASS CMP) mess"%e* S#"r# $rom se&d&% mess"%e ASS CMD "&d s#o '!e& ASS CMP rece.ed*
Ms# 0e se# #o roer ."e G I& #!e c"se o$ c" se#, #!e se##&% ms# $oo' #!e re ? T14 TTRAU
