optimization guidelines - accessibility ericsson - rev01

5/28/2018 Optimization Guidelines - ACCESSIBILITY Ericsson - Rev01

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Optimization Guidelines:Accessibility in Ericsson

CONTENTS

1 INTRODUCTION.............................................................................................................................3

2 ACCESSIBILITY..............................................................................................................................4

2.1 Idle Mode..................................................................................................................................................4

2.2 Call Establishment Process.................................................................................................................. ...4

3 ACCESSIBILITY KPIs (Key Performa!e I"#!a$ors%...................................................................&

3.1 High Level KPIs.......................................................................................................................................53.1.1 Call Setup Success Rate - CSSR (%)..................................................................................................................5

3.1.1.1 CS CSSR (%).........................................................................................................................................5

3.1.1.2 PS CSSR (%).........................................................................................................................................5

3.1.1.3 CS CSSR (%) from P7.1-....................................................................................................................6

3.1.1.4 PS CSSR (%) from P7.1-....................................................................................................................6

3.1.2 Oerall Ser!ce "ccess!#!l!t$ - OS"C (%).........................................................................................................7

3.2 Medim Level KPIs.................................................................................................................................!3.2.1 RRC Coect!o Success Rate (%).....................................................................................................................&

3.2.1.1 RRC Coect!o Success Rate CS (%).................................................................................................&

3.2.1.2 RRC Coect!o Success Rate PS (%).................................................................................................&

3.2.2 'u S!all! sta#l!s*met Success Rate (%)....................................................................................................&

3.2.2.1 'u-CS S!all! sta#l!s*met Success Rate (%)................................................................................&3.2.2.2 'u-PS S!all! sta#l!s*met Success Rate (%)................................................................................+

3.2.3 ,"S S!all! sta#l!s*met Success Rate (%) from P7.1-...........................................................................+

3.2.3.1 ,"S CS S!all! sta#l!s*met Success Rate (%) from P7.1-......................................................+

3.2.3.2 ,"S PS S!all! sta#l!s*met Success Rate (%) from P7.1-......................................................+

3.2.4 (R") sta#l!s*met Success Rate (%)..............................................................................................................+

3.2.5 Se! Pa! /a!lure Rate (%)........................................................................................................................+

3.2.6 loc0! Pro#a#!l!t$..........................................................................................................................................1

3.2.6.1 oS Speec* (%)...................................................................................................................................1

3.2.6.2 oS PS (%)..........................................................................................................................................1

3.3 "ailres a#ter $dmission %ate &'()......................................................................................................11

4 PER'ORANCE ANALYSIS.......................................................................................................12

4.1 $dmission Control.............................................................................................................................. ...124.1.1 "m!ss!o Pol!c$...............................................................................................................................................12

4.1.2 Resources to #e mo!tore................................................................................................................................13

4.1.2.1 R/ Poer.............................................................................................................................................13

4.1.2.2 Coe ree Cosumpt!o......................................................................................................................134.1.2.3 a "S..................................................................................................................................13

4.1.2.4 S/ Coe !m!t (Coe 8$storam).......................................................................................................13

4.1.2.5 8SP" a coect!os !m!t...................................................................................................13

4.1.2.6 a C*ael lemets.............................................................................................................13

4.1.3 RRC "m!ss!o loc0s.....................................................................................................................................13

4.1.4 R" "m!ss!o loc0s....................................................................................................................................13


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4.2 MP Load &High *rocessor Load(........................................................................................................ ..14

4.3 $#ter $dmission..................................................................................................................................... 144.3.1 /a!lure after "m!ss!o9 'u# Coest!o.........................................................................................................14

4.3.1.1 o RRC Success Rate.......................................................................................................................15

4.3.1.2 o R" Success Rate.......................................................................................................................154.3.2 /a!lure after "m!ss!o9 Core rasport ,etor0 Coest!o.......................................................................15

4.3.3 /a!lure after "m!ss!o9 8arare sae (C*ael lemets)......................................................................15

4.3.4 /a!lure after "m!ss!o9 C*ael!:at!o Coes...............................................................................................16

4.3.5 /a!lure after "m!ss!o9 Ot*ers.......................................................................................................................16

4.4 $ccessibilit+ isses not detected b+ conters.................................................................................. .....1,4.4.1 8; Pro#lems ! t*e RS..................................................................................................................................164.4.2 'terferece.................................................................................................................................................17

4.4.3 R"C8 m!scof!urat!o....................................................................................................................................17

4.4.4 Cell aa!la#!l!t$.............................................................................................................................................17

4.4.5 ,oe loc0!...................................................................................................................................................17

& RE'ERENCES...............................................................................................................................1)

* ANNE+ I, UE I"-e o"e Pro!e"res............................................................................................1/

,.1 PLM- election and %eselection..........................................................................................................1/

,.2 %eading +stem In#ormation...................................................................................................... ..........20

,.3 Cell election and %eselection...............................................................................................................216.3.1 Cell Select!o.....................................................................................................................................................2

6.3.2 Cell Reselect!o.................................................................................................................................................2

6.3.3 ocat!o Setup....................................................................................................................25

!.4 Core -etor -egotiation ....................................................................................................................2,

!.5 %adio $ccess earer &%$( et* and %econ#igration....................................................................2!


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1 INTRODCTION

This series of Optimization Guidelines covers all the main topics regarding

Performance Monitoring & Analysis

Configuration settings

Troubleshooting

Refer to the internal Claro document Optimization Process! "#$O%OTM%OP'((()* for a summary of 'G +C#MARadio Access ,et-or. Optimization /asics%

This specific document focuses on ACCESSI!I"IT# and its specifics -ithin ERICSSONinfrastructure "Release P0%1)%

Target users for this document are all personnel re2uiring a detailed description of this process "AccessibilityOptimization)* as -ell as configuration managers -ho re2uire details to control the functions and optimize parametersettings% t is assumed that users of this document have a -or.ing .no-ledge of 'G telecommunications and arefamiliar -ith +C#MA%

Document Re$ision Control

Re$ision Date Aut%or C%an&es

#raft (1 1'3,ov34((5 6C$78$ricsson 9irst Release of the document

(1 143Mar34(1( 6C$78$ricsson

:pdate from P0 to P0%1;

,A7 signalling phase counters added* both to C77R


4/27

' ACCESSI!I"IT#

Accessibility is the ability of a service to be obtained -ithin specific tolerances and other given conditions* -henre2uested by the user% n other -ords* the ability of a user to obtain the re2uested service from the system%

Target is to get a 1((? Accessibility* i%e%* all users al-ays get the service they re2uest%Poor Accessibility is typically due to

some form of congestion "before or after Admission Control@)

hard-are8soft-are fault "Chec. A=ARM7* Cells #o-ntime* tic.ets in R$M$#B) misconfiguration "A:#T the settings in R,C)

other reasons "for instance* it is also possible that there is some e>ternal source of interference "such as a

micro-ave lin. on the same fre2uency) affecting the accessibility)

Accessibility is to be monitored independently for the different RA/ types "e%g% 7peech* C7 ideo* P7 nteractive R55*P7 nteractive D7#PA* etc%) as in certain situations only one of the RA/ types -ill be affected%

'(1 Idle )ode

Accessibility issues may occur related to the :$ idle mode behavior%

The :$ in dle mode performs ne>t E main tas.s FRefer toA,,$ for a brief revie-H;

P=M, selection and reselection Reading system information "M/* 7/)

Cell selection and reselection

=ocation area "=A) and routing area "RA) registration8update

Paging procedure

7ettings should guarantee that the :$ in idle mode is al-ays in the best conditions to access the net-or. "i%e%* toinitiate a Mobile Originated call* MO) and be reached by the net-or. "i%e%* to receive a Mobile Terminated call* MT)%

'(' Call Establis%ment *rocess

$ach step in the Call $stablishment process should be monitored in order to clearly identify -here the accessibilityissue is located% 9or a more complete revie- of the Call $stablishment Process* refer toA,,$ %


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+ ACCESSI!I"IT# ,*Is -,ey *er.ormance Indicators/

/elo- the main metrics used for Accessibility Monitoring of a 'G +C#MA8:MT7 ,et-or.* and their implementation-ith Ericssoncounters%

Refer to 7MART #ocumentation! for further details on the actual implementation of these


6/27

7imilar formulas can be used for each specific RA/ C77R* i%e%* P7 7treaming C77R "?) or P7 nteractive C77R "?)%

Refer to the internal Claro doc% Optimization Guidelines; Capacity in $ricsson! "#$O%OTM%OP'(N1) for further detailsregarding the $ricsson features =oad 7haring and #irected Retry%

9rom P0%1 "P0 9P)* current release in Claro* ne- counters are available for monitoring the performance of the NASSi&nallin& p%ase"i%e% after : 7ignalling Connection establishment and before RA/ Assignment Re2uest)%

,e- formulas -ill also cover the Iu Si&nallin& Connectionp%aseperformance through counters already availablebefore P0%1 in MO R,C9unctionQ therefore* the same u 7ig% Conn% 7uccess Rate value is to be applied to all:tranCells under the same R,C%

As the ne- formulas belo- -ill compute failures in these 4 additional phases "see ne>t figure)* a slight degradation inthese


7/27

1% /y adding pmTot,oRrcConnect7uccess"Att)ratCellResel"CcOrder) counters in the RRC term* this


8/27

pppp+('(1 RRC Connection Success Rate -2/"9or all connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish a generic radio connection bet-een :$s and R,C starting fromidle mode state%

,otes;

pm,oOfReturningRrcConn "number of =oad 7haring diversions -hen establishing an RRC connection that

returns to the first fre2uency) is not available per domain "C7* P7)* so ne>t t-o metrics are missing thiscorrection%

RRC connection attempts are not corrected for emergency calls redirections% Counters

pm,oOfRedirected$mergencyCalls and pm,oOfReturning$mergencyCalls "MO R,C9unction) could beused to estSmate their contribution at R,C level%

#ue to the fact that the :$ may perform cell re3selection during the RRC Connection establishment "it may

repeat RRC Connection Re2uest message ,'(( times -hich may arrive at different cell) and the fact that+C#MA RA, "the R,C) does not double count the duplicated RRC Connection Re2uest messagesreceived* there is a chance that the RRC access success rate for some cells may sho- values above 1((?%

The access success rate better than 1((? happens -hen the attempt is registered in a cell different to thecell -here the success is registered% The end result is a slightly better success rate for the cell that completesthe access and a slightly -orst success rate for the cell -here the access -as attempted8started%

+('(1(1 RRC Connection Success Rate CS -2/"9or C7 connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish a radio connection bet-een :$s and R,C starting from idlemode state in particular affecting CS services (speech and video calls).

+('(1(' RRC Connection Success Rate *S -2/"9or P7 connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish a radio connection bet-een :$s and R,C starting from idlemode state in particular affecting PS services.

+('(' Iu Si&nallin& Establis%ment Success Rate -2/"9or all connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish the u part of the Control Plane bet-een the R,C and COR$%,ote these counters are in MO R,C9unction "hence* only available at R,C level)%

+('('(1 IuCS Si&nallin& Establis%ment Success Rate -2/"9or C7 connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish the u part of the Control Plane bet-een the R,C and C7domain COR$.

nn)rningRrcCopm,oOfRetu3onnharingRrcC"pm,o=oad73ConnectRe2pmTot,oRrc

7uccessConnectRe2pmTot,oRrcK1((

nnCsaringRrcCopm,o=oad7h3CsConnectRe2pmTot,oRrc

Cs7uccConnectRe2pmTot,oRrcK1((

nnPsaringRrcCopm,o=oad7h3PsConnectRe2pmTot,oRrc

Ps7uccConnectRe2pmTot,oRrcK1((

+

+

temptPsstablishAtpm,o&u7ig$temptCsstablishAtpm,o&u7ig$

ccessPsstablish7upm,o&u7ig$ccessCsstablish7upm,o&u7ig$K1((

temptCsstablishAtpm,o&u7ig$

ccessCsstablish7upm,o&u7ig$K1((


9/27

+('('(' Iu*S Si&nallin& Establis%ment Success Rate -2/"9or P7 connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish the u part of the Control Plane bet-een the R,C and P7domain COR$.

+('(+ NAS Si&nallin& Establis%ment Success Rate -2/ 5.rom *6(1"9or all connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish the u part of the Control Plane bet-een the R,C and COR$%,ote these counters are in MO R,C9unction%

+('(+(1 NAS CS Si&nallin& Establis%ment Success Rate -2/ 5 .rom *6(1"9or C7 connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish the u part of the Control Plane bet-een the R,C and C7domain COR$.

+('(+(' NAS *S Si&nallin& Establis%ment Success Rate -2/ 5 .rom *6(1"9or P7 connection re2uests)

=o- value "e%g% 5E?) indicates problems to establish the u part of the Control Plane bet-een the R,C and P7domain COR$.

+('(7 -RA!/ Establis%ment Success Rate -2/

+here "RA/) J 7peech* CsN* CsE0* Pac.etnteractive* Pac.etnteractiveDs* Pac.etnteractive$ul* Pac.et7tream*Pac.et7tream14 or Pac.et7treamDs%,ote that these counters for Pac.etnteractive include also Pac.etnteractiveDs* and counters for Pac.etnteractiveDsinclude also Pac.etnteractive$ul%

9or 7peech RA/* please refer to comments on 7ection '%1%1%' regarding different possibilities to modify this formula

for RA/ $stablishment 7uccess Rate so it can also cover as 'G access failures those directed retries to gsm andincoming RAT DOs that fail%

=o- value "e%g% 5E?) indicates problems to establish a RA/ after the RA/ assignment coming from the COR$net-or.%

+('(9 Sendin& *a&in& ailure Rate -2/

temptPsstablishAtpm,o&u7ig$

ccessPsstablish7upm,o&u7ig$K1((

mpt"RA/)ablishAttepm,oRab$st

ess"RA/)ablish7uccpm,oRab$stK1((

+++

+

adCscardCmp=opm,oPage#i:e=agingTo&dlepmCn&nitPa:eRagingTo&dlepmCn&nitPa:egingTo&dlepmCn&nitPa

anReIectedAttempt:trpm,oPagingadCscardCmp=opm,oPage#iK1((

Ps7uccConnectRe2pmTot,oRrcCs7uccConnectRe2pmTot,oRrc

easePs,as7ignRelpm,o7ystemeaseCs,as7ignRelpm,o7ystem1K1((

+

+

Cs7uccConnectRe2pmTot,oRrc

easeCs,as7ignRelpm,o7ystem1K1((

Ps7uccConnectRe2pmTot,oRrc

easePs,as7ignRelpm,o7ystem1K1((


10/27

Digh value "e%g% U4?) indicates problems to send paging through the radio net-or. due to overload%9ormula above is valid if :RAVPCD state is disabled "current situation in Claro)% n case it is enabled* the 9ormulashould be replaced by the follo-ing one;

FPending Confirmation from $ricssonH

+('(; !loc


11/27

+(+ ailures a.ter Admission Rate -2/:

This


12/27

7 *EROR)ANCE ANA"#SIS

9ollo-ing the Hierarchical KPIs methodology described in the internal Claro doc% Optimization Process!"#$O%OTM%OP'((()* once identified areas8nodes8cells sho-ing bad performance through the overall ample of a guaranteed re2uest is 7peech* C7 conversational* C7 orP7 streaming and P7 interactive 8%

+hen the re2uest is for resources e>ceeding the minimum needed for satisfying the 6o7 "for e>ample up3s-itch

interactive P7 to a higher dedicated rate)* the re2uest is non-guaranteed% $>ample of a non3guaranteed re2uest isP7 interactive%


13/27

7(1(' Resources to be monitored

7(1('(1 R *o=er

=ac. of #o-nlin. Po-er "pm,o9ailedRab$stAttempt=ac.#lP-r)

,ote; The R9 po-er is measured and regulated at the reference point and also the po-er limits have to be calculatedat the reference point%

7(1('(' Code Tree Consumption

=ac. of Canalization Code "pm,o9ailedRab$stAttempt=ac.#lChnlCode)

,ote; The code tree consumption is measured in percentage of the total tree size by e>cluding the fi>ed codesallocated for D7#PA "i%e% the higher the number of codes allocated for D7#PA the smaller -ill be the available treeand higher the relative consumption)%

The admission limit is set by dlCodeAdm "as a percentage)%

7(1('(+ D" and " ASE

=ac. of #o-nlin. A7$ "pm,o9ailedRab$stAttempt=ac.#lAse)=ac. of :plin. A7$ "pm,o9ailedRab$stAttempt=ac.:lAse)

,ote; A7$ is used as an overall measurement of the cell load on the air interface but A7$ is not a real cell resource% tintends to e>press the static load on the air3interface caused by radio bearers in a cell* relative to the static loadcaused by a set of conversational%

7(1('(7 S Code "imit -Code 0ysto&ram/

$>ceed 79 histogram "pm,o9ailedRab$stAttempt$>ceedConn=imit)

,ote; n order to limit the number of high codes and D+ consumption RA/s specific thresholds are set for each 79%

7(1('(9 0SD*A and E" connections "imit

R, Admission Control bloc.s ne- radio lin. admission re2uests -hich involve the allocation to D73#7CD8D737CCD-hen the number of users assigned to the D73#7CD in the cell e>ceeds the load control level hsdpa:sersAdm% R,

Admission Control shall reIect an $:= user* re2uesting the cell as serving cell if the total number of serving cell $:=users including the re2uested is above eul7ervingCell:sersAdm%

7(1('(; " and D" C%annel Elements

=ac. of #= Channel $lements "pm,o9ailedRab$stAttempt=ac.#lD-)=ac. of := Channel $lements "pm,o9ailedRab$stAttempt=ac.:lD-)

,ote; The D+ resources are monitored by Admission Control as ay other physical resource% 7oft congestion is used tocontrol the overload% The follo-ing thresholds are used; dlHwAdm ulHwAdm

7(1(+ RRC Admission !loc


14/27

mpt7peechablishAttepm,oRab$st

7peechoRe2#eniedpm,oOf,onDK1((

mptCsE0)ablishAttepm,oRab$stemptCsMNtablishAtt"pm,oRab$s

CsoRe2#eniedpm,oOf,onDK1((

+

nteractivemptPac.et&ablishAttepm,oRab$st

e&nteractivoRe2#eniedpm,oOf,onDK1((

treammptPac.et7ablishAttepm,oRab$st

gPs7treaminoRe2#eniedpm,oOf,onDK1((

DsnteractivemptPac.et&ablishAttepm,oRab$st

DsoRe2#eniedpm,oOf,onDK1((

$ulnteractivemptPac.et&ablishAttepm,oRab$st

$uloRe2#eniedpm,oOf,onDK1((

tream14mptPac.et7ablishAttepm,oRab$st

Ps7tr14oRe2#eniedpm,oOf,onDK1((

,ote; RA/ admission bloc.s could have more impact on accessibility compared to RRC bloc.s* especially for P7services* since the re2uired resources during the RA/ assignment are higher%

7(' )* "oad -0i&% processor "oad/

Chec. pm,oReIRrcConnMp=oadC 3 ,umber of reIected RRC connections due to MP load control%

,ote; The module MP handles signalling associated -ith traffic events%Connection setup and release "7peech* P7 R55* D7* =A update* 7M7)%

7(+ A.ter Admission

,umber of Radio Resource Control "RRC) or Radio Access /earer "RA/) establishment re2uests failed after beingadmitted by admission control%f either a RRC or RA/ establishment procedure fails A9T$R the admission has been granted for the establishment"RRC or RA/)* counter pm,o9ailedAfterAdm -ill be incremented at the cell or cells -here the :$ is located%

9ollo-s a list of causes for failures after admission;

Transport failures

T, failure reasons

AA=4 setup failure "due to congestion or miss configuration)

Code allocation failures

Channel elements allocation failures

,/AP R= setup failure "RA or T/ congestion)

D+ fault in the R/7

:$ failures

Timeout in the :$* R,C or R/7

nvalid parameter settings

7(+(1 ailure a.ter Admission: Iub Con&estion

ub congestion is a common reason for high number of failures after admission events%#epending on the volume of traffic per service or RA/* certain 6o7 could be congested at the AA=4; All RA/se>cluding D7#PA are configured to use Class A or Class / being these t-o mostly impacted by congestion% Most ofthe time Class / is the first 6o7 to get congested leading to failures after admission events%ub congestion could also be caused by $1 issues%Misconfiguration of AA=4 profile at the ,ode /* R,C or R8M7, can lead to ub congestion as -ell%

Possible indicators ;

Chec. for congestion at the ub lin. "7ee belo-)Chec. for $1 issues and history of alarms of $1s "for intermittent $1 alarms)


15/27

Possible solutions for ub congestion ;

$nable #irected retry "short term solution)%Correct possible AA=4 miss configuration at ,ode /* R,C and R "AA=4 profile must match in all entities)Order ne- $1s "long term solution)%Change AA=4 6o7 configuration depending on services re2uest volume "C7 voice* R55 data* D7#PA* etc)%

7(+(1(1 "o= RRC Success Rate

n case a poor RRC 7uccess Rate is detected and neither Admission /loc.s nor MP =oad reIections can e>plain sucha degradation of the RRC Accessibility* then chec. these 4 counters;

pm,oRrcConnRe2/loc.TnCsRRC C7 failures due to congestion on the user plane "AA=4) or control plane ":ni7aal or 7CTP) of the transportnet-or.%

pm,oRrcConnRe2/loc.TnPsRRC P7 failures due to congestion on the user plane "AA=4) or control plane ":ni7aal or 7CTP) of the transportnet-or.%

f none of the above counter values can e>plain the poor RRC success rate more traces have to be considered e%g%:$TR "AA=4) or control plane ":ni7aal or 7CTP) of the transport net-or.%

7(+(1(' "o= RA! Success Rate

7imilar analysis can be done for RA/s /loc.ed due to transport net-or. congestion including;

7peech;

ideocall;

P7 R55;

D7#PA;

7(+(' ailure a.ter Admission: Core Transport Net=or< Con&estion

Accessibility issues are observed on all sites at the R,C -ithout maIor issues -ith ub congestion "especially at pea.hour); Congestion -ill be observed at u3C7 "R,C33UMG+) or u3P7 "R,C33U7G7,) lin.s%


#egradation of pected in this case%

,ote; Congestion -ill be observed at Aal4 access point "Aal4Ap) entity starting -ith g!%"Aal4Ap entities starting -ith b! correspond to node b* starting -ith r! corresponds for ur lin.s* etc)

Possible solutions ;

This issue -ill re2uire support from the Operation and Maintenance department "OMC) in order to determine thereasons for that high utilization over u3C7 and u3P7 lin.s%

7(+(+ ailure a.ter Admission: 0ard=are sa&e -C%annel Elements/

=ac. of channel elements could be due to insufficient := "RA board) or #= "T board) hard-are capacity% Channelelement capacity could be also soft-are limited% Admission control is restricted by ulD-Adm and dlD-Admparameters% They should be set at 1((? so no hard-are is limited for RRC8RA/ setup%

mpt7peechablishAttepm,oRab$st

ech/est/loc.Tn7pepm,oRab$stK1((

Ds)nteractivemptPac.et&ablishAttepm,oRab$st3e&nteractivemptPac.ettablishAtt"pm,oRab$s

tnt,onDs/es/loc.TnPs&pm,oRab$stK1((

DsnteractivemptPac.et&ablishAttepm,oRab$st

ntDs/est/loc.TnPs&pm,oRab$stK1((

mptCsMNablishAttepm,oRab$st

N/est/loc.TnCsMpm,oRab$stK1((


16/27


Digh number of AC bloc. events on =ac.#lD- -ould indicate issues -ith T board and =ac.:lD- -ould indicateissues -ith RA board%Congestion at RA or T could be indicated by R/7 counters pm:lCredits and pm#lCredits respectively%Congestion per spreading factor "79) can be also measured using pm7etup9ailure7f R/7 counters from the/asebandPool "//P) on the uplin. ":= //P) and the do-nlin. "#= //P)%


Chec. that ulD-Adm and dlD-Adm parameters are set to 1((?Chec. numDsResources* num$ulResources at the node / "long term solution)Reduce value of sfAdm to ( "short term solution)Chec. for hard-are failures on RA and T/ boards and given the case* order its replacement%Order an additional ne- RA or T/ board* depending on the specific case%

7(+(7 ailure a.ter Admission: C%annelization Codes

This could also be a reason for 9ailures after Admission* but it is e>pected to be correlated -ith high figures also in thecounter for admission bloc.s due to lac. of channelization codes "pm,o9ailedRab$stAttempt=ac.#lChnlCode)%


Reduce the AC threshold for connections -ith lo- 79 "specially in #=* N in :=)% 7hort Term 7olution%Real need for additional O79 codes "purely due to increase in traffic) -ill re2uire of ne- carrier8sector8site

analysis% FRefer to doc% Optimization Guidelines; Capacity in $ricsson! "#$O%OTM%OP'(N1)* for further detailsregarding the methodology to decide the best option bet-een ,e- Carrier or ,e- 7ector or ,e- 7iteH%

7(+(9 ailure a.ter Admission: Ot%ers

f a site sho-s none of the previously described issues* then it is li.ely to be a more complicated problem to solveQoften relating to a soft-are8hard-are fault* or perhaps an e>ternal source of interference in the area%

Chec. for neighboring sites; Remember that neighboring sites having AA=4 congestion can cause other cells to havehigh number of failures after admission "due to soft handover)

Chec. that soft-are revisions are up to date at the ,ode /

Chec. for une>pected figures in counter pm,onvalidRab$stablishAttempts%

RA,AP RA/ Assignment message is received for RA/s to be setup8modified and the received 6o7 parameterscannot be mapped to a supported RA/ type or if the data in the message contains a critical logical error%

7(7 Accessibility issues not detected by counters

7ome .inds of RRC failures could not be detected by counters or other traces% This typically happens -hen the RRCConnection Re2uest messages from the :$ cannot reach the R,C% n this case the accessibility *roblems in t%e R!S

Antenna system failures

RA boards failures

Cell unavailability

Most of the related problems should raise an alarm%


17/27

7(7(' " Inter.erence

7trong := nterference could also be the cause of some Accessibility issues not clearly detected by counters describedso far% t can be monitored by chec.ing;5(th percentile ofpmAverage!ssiU 35( d/m or "pmSum"l!ssi # pmSamples"l!ssi) U 35E d/m

7(7(+ RAC0 miscon.i&uration

Chec. RACD parameters to loo. for a -rong setting;

aichPo-erpo-erOffsetP(po-erOffsetPpmpreambleRetransMa>ma>PreambleCycleconstantalueCprachma>T>Po-er:l

7(7(7 Cell na$ailability

Chec. Cell unavailability through the follo-ing counters;

pmcell#o-nTimeAutopmCell#o-nTimeMan

7(7(9 Node !loc


18/27

9 REERENCES

F1H $C%&A ("&'S) %eploment Handoo*. Planning and +ptimi,ation Aspects % Christophe Chevallier* Christopher/runner* Andrea Garavaglia*


19/27

; ANNE? I: E Idle )ode *rocedures

P=M, selection is the first step in the registration process that allo-s a :$ to initiate or receive services from anoperator% The :$ normally operates on its Dome P=M,% Do-ever* a isited P=M, "P=M,) may be selected if the :$loses coverage%

A :$ successfully registers on a P=M, if it finds a suitable cellto camp on -ithin the selected P=M,% The :$ -illthen obtain a location or routing registration ac.no-ledgement in the area of the cell on -hich it is camped% The :$displays to the user that this P=M, is registered%

+hen a :$ does not find a suitable cell in the selected P=M,* it tries to camp on any other acceptable cell-ithin anallo-ed P=M,%

+hen there is a suitable cell available normal ser$icescan be obtained in the cell% f there is an acceptable cellavailable only emer&ency callsare available* and if in automatic mode* ne- P=M, selection%

;(1 *")N Selection and Reselection

P=M, selection is a ,A7 function* but the A7 provides the list of available P=M,s from -hich the selection is made%A7 reports all successfully read P=M, identities to the ,A7* in 4 groups;

Those that meet the high 2uality criterion;

o R7CP CPCD UJ 35E d/m* for 9## cells

o R7CP CPCD UJ 3N d/m* for T## cells

o R77 CPCD UJ 3E d/m* for G7M cells

Those that do not% These ones together -ith their measured CPCD R7CP value* so they can be ran.ed%

The standard allo-s for the optimization of this measuring and reporting process through the use of stored informationin the :$ regarding carrier fre2uencies and other cell parameters as scrambling codes%

Once a suitable list of available P=M,s is compiled* it is up to the ,A7 to select a P=M, for registration% This may bedone automatically or manually% , automatic mode the available P=M,s are listed in priority order and the highestpriority P=M, is selected% n manual mode a list of the available P=M,s is presented to the user in priority order* butthe user may select any P=M, from the list%

Prioritization for both modes is as follo-s;

1% Dome P=M, "DP=M,)4% P=M,s in the :ser Controlled P=M, 7elector -ith Access Technology! data field in the 7M in priority order%'% P=M,s in the Operator Controlled P=M, 7elector -ith Access Technology! data field in the 7M in priority order%N% Other P=M,s that meet the high32uality criterion in random order%E% Other P=M,s that do not meet the high32uality criterion in order of decreasing signal 2uality%


20/27

Once a P=M, is selected this is indicated to the A7 along -ith the selected radio access technology%

;(' Readin& System In.ormation

The 7ystem nformation /loc. "7/) messages are sent on /CCD logical channel* -hich can be mapped;

to the /CD for :$s in idle mode* CellVPCD and :RAVPCD

or the 9ACD transport channel for :$s in CellV9ACD%

To inform the :$ if a change in 7ystem information has occurred* the M/ also delivers a value tagfor each 7/%

To inform :$s in idle mode* CellVPCD and :RAVPCD of a change in the system information* paging "Paging type 1!)is used to deliver the $ /CCD modification info! to notify the ne- value tag for the M/% +C#MA RA, can alsoinform of the change in the system information -ith a 7ystem nformation Change ndication message on the 9ACDtransport channel%


21/27

;(+ Cell Selection and Reselection

Refer to the Configuration Guideline; dle Mode 7ettings! for a more detailed description%

;(+(1 Cell Selection

,e>t figures summarize the process%

;(+(' Cell Reselection

,e>t figure summarizes the process%


22/27

;(+(+ "ocation3Routin& Area pdate

=A and RA updating is necessary to inform the C, of the current =A or RA of the :$* so that the net-or. can send apaging message to the :$%

There are three types of =A and RA registration updates;

nternational Mobile 7ubscriber dentity "M7) attach or detach

,ormal =A and RA updating

Periodic =A and RA updating "T'414* T''14)

A border R/7 can handle less traffic than an R/7 placed inside the =A* due to the increased signalling load%Therefore* it is recommended that he =A8RA borders should be placed in areas -ith lo- traffic%

f the =As8RAs are small* there -ill be more =A:s8RA:s in the system and a high number of border R/7s% On theother hand* if the =As8RAs are large the number of paging messages -ill increase%

f the same =A8RA is used for the G7M and +C#MA net-or.s* the conse2uence is heavy paging load in 'G arisingfrom the G7M subscribers%

RRC MO#$7 and 7TAT$7=A8RA :P#AT$ vs% C$== :P#AT$ vs% :RA :P#AT$


23/27

;(+(7 *a&in& *rocedure

*a&in& Type 1"to :$ in idle mode or dormant state; CellVPCD8:RAVPCD)

:$ terminating service re2uest for P7 or C7 services "C, initiated)%

:TRA, initiated broadcast to inform :$s -hen 7 is modified%

Channel s-itch from state :RAVPCD to C$==V9ACD ":TRA, initiated)

T-o different physical channels are used in order to e>change proper information bet-een the +C#MA RA, and the:$; the PCD and the 73CCPCD "carries the PCD)% There is a fi>ed timing relation bet-een a PCD frame and theassociated 73CCPCD frame%

#iscontinuous Reception "#R); The :$ listens to the PCD only at certain predefined times* reducing po-erconsumption%

The paging record varies in length depending on -hether it includes the :$ identity in terms of M7* TM7* or P3TM7%A PCD frame can carry one Paging Type 1! message of 1( ms and may contain bet-een '3E paging records*depending on -hether the paging uses M7 or TM78P3TM7%

*a&in& Type '"to :$ in CellV#CD or CellV9ACD) :$ terminating service re2uest for P7 or C7 services "C, initiated)%

+hen a connection e>ists bet-een the +C#MA RA, and the :$* the 7R,C determines that a RRC connection hasalready been established by this :$ and the RRC message [Paging type 4[ is used to carry paging information% 7inceit is sent on a dedicated control channel* this message is intended only for one particular :$%

9or paging* the capacities of the 9ACD and the RACD are assumed to be enough* but there is a ris. of congestion inthe PCD due to heavy paging load% Therefore* the probability of congestion in the PCD must be calculated in order todimension the =A8RA%


24/27

6 ANNE? II: Call Establis%ment *rocedure

6(1 @oice Call Establis%ment

6(' *S Data Call Establis%ment

6(+ Radio Resource Control -RRC/

RRC is the overall controller of the Access 7tratum* responsible for configuring all other layers in the Access 7tratumand providing the control and signalling interface to the ,A7 layer%

/roadcast of 7ystem nformation

RRC Connection Management

Radio /earer Management

RRC Mobility 9unctions

Paging and ,otification 9unctions

Routing of Digher =ayer Messages

Control of Ciphering and ntegrity Protection

Measurement Control and Reporting


25/27

Po-er Control 9unctions

RRC manages radio resources* including allocation* deallocation* and configuration of =ogical* Transport* and Physical

Channels* measurement reporting* security procedures* and overall management of the Access 7tratum%

6(+(1 RRC connection Reuest B Setup

The RRC Connection 7etup establishes 7R/s "7ignalling Radio /earers) to carry dedicated signalling%This phase of the call establishment is identical for C7 and P7 calls "both MO and MT) and it is al-ays composed byne>t three messages;

1% RRC Connection Re2uest "RACD* in :=)4% RRC Connection 7etup "9ACD* in #=)'% RRC Connection 7etup Complete "#CD* in :=)

t is important to note that this signalling is also needed -hen the :$ performs Periodic Registration8 =A:8RA:8#etachas part of the Mobility Management% n these cases* the purpose of the RRC connection setup is not to establish a call"C7 or P7)* and therefore* there -ill not be RA/ setup phase%

The RRC connection re2uest contains the :$ identity* optional cell measurement results* and the establishmentcause%


26/27

'GPP T7 4E%''1 %'%1

Radio Resource Control -RRC/ *rotocol Speci.ication -Release D/

7ection% 1(%'%'%11% $7TA/=&7DM$,T CA:7$

Originating Conversational Call*

Originating 7treaming Call*

Originating &nteractive Call*

Originating /ac.ground Call*

Originating 7ubscribed traffic Call*

Terminating Conversational Call*

Terminating 7treaming Call*Terminating &nteractive Call*

Terminating /ac.ground Call*

$mergency Call*

&nter3RAT cell re3selection*

&nter3RAT cell change order*

Registration*

#etach*

Originating Digh Priority 7ignalling*

Originating =o- Priority 7ignalling*

Call re3establishment*

Terminating Digh Priority 7ignalling*

Terminating =o- Priority 7ignalling*

Terminating \cause un.no-n*

M/M7 reception*

M/M7 ptp R/ re2uest

9or speech AMR service* this cause is recorded as either Originating Conversational Call! or TerminatingConversational Call!% 9or P7 service* this cause is recorded as Originating8Terminating nteractive8/ac.ground Call!%7uccessfully establishing the RRC connection is the most challenging part of call setup% This can be attributed to t-ofactors; the admission control implementation and the size of the RRC Connection 7etup message% The latter is themain challenge% #uring admission control implementation* an RRC connection reIect is sent if no resources areavailable for allocation* or if the call should be redirected to a different system or carrier%

After successful resource allocation* the RRC Connection 7etup message\-hich contains 7R/ information includingthe mapping details of dedicated logical* transport* and physical channels\is sent on the 9or-ard Access Channel"9ACD) "over F#o-nlin. 7econdary Common Control Physical ChannelH F#= 7CCPCDH)% This RRC Connection 7etupmessage contains a significant amount of information* and it spans multiple frames -hile not yet operating in closedloop po-er3controlled condition% This ma.es it difficult for the :$ to receive the message* especially if the 7CCPCDpo-er allocation is not set to accommodate lo- geometry%

After the RRC Connection 7etup message is received* the :$ can set up the lo- data rate #CD according to the RRCConnection 7etup message% 9irst* only the P#CCD containing Transmit Po-er Control "TPC) and Pilot bits are sent to

allo- the inner loop po-er control to converge% After-ards* the RRC Connection 7etup Complete message is used toac.no-ledge the setup message and send :$3capability information to the net-or.% At this point* the :$ should havetransitioned from dle state to C$== #CD state% At this time* the connection is po-er3controlled and may supporthandover* depending on the :niversal Terrestrial Radio Access ,et-or. ":TRA,) implementation% /oth featuresimprove the reliability of the connection%

6(7 Core Net=or< Ne&otiation

The lo- data rate #CD facilitates upper layer signaling -ith the ,A7 layer* -hich performs all authentication andsecurity procedures along -ith additional processes in the C, to establish the end3to3end connection%


27/27

To initiate the connection re2uest to the upper layers* MO calls use the Connection Management "CM) 7erviceRe2uest and MT calls use the paging response% n the CM 7ervice Re2uest message* the CM 7ervice Type fieldindicates Mobile originating call establishment! as the cause for a MO AMR call% The Paging Response message doesnot need to carry service information because the ,A7 layer already .no-s -hat service is being set up for the MTcall%

To perform t-o3-ay authentication* the :$ chec.s the Authentication To.en "A:T,) nd the net-or. chec.s the7igned Authentication Response "7R$7)* -hich is calculated from the RA,# number from the net-or.% #epending onthe supported security capabilities* ciphering and integrity protection are s-itched on to enable encryption of user dataand signaling messages%

9or MO calls* the :$ sends main parameters such as bearer capabilities and dialed digits to the net-or. using the CallControl "CC) 7etup message% 9or MT calls* the net-or. uses the 7etup message to send the same* or similar*information to the :$% The ne>t step is similarQ MO calls use Call Proceeding messages ":TRA, to :$)* -hile MTcalls use Call Confirmed messages ":$ to :TRA,) as a =ayer ' ac.no-ledgment%

6(9 Radio Access !earer -RA!/ Setup and Recon.i&uration

After the C, negotiation* the :$ can establish the #CD"s) for the re2uested service% $>isting #CDs also may bereconfigured to meet the re2uirements* depending on the current configuration% /efore sending the R/ 7etupmessage* call admission control must be chec.ed and resource allocation performed for every resource involved in acall%

9or AMR voice* the :$ typically sets up three dedicated logical8transport channels mapped onto one CCTrCh%nformation in the R/ 7etup message is similar to the RRC Connection 7etup;

,A7 =ayer 4% Radio /earer8logical8transport channel mapping

=ayer 4% Channel coding* Radio =in. Control "R=C) parameters* TT* /=$R targets* Transport

9ormat Combination 7et "T9C7)

=ayer 1% 7preading 9actor "79)* O79 code* 7crambling Code* frame offset* po-er control

parameters

At this point* the radio lin. is completely establishedQ ho-ever* the end3to3end connection is not yet fully established;

The Alerting message is sent from the net-or. to the :$ for MO calls* or from the :$ to the net-or.

for MT calls%

The directions for Connect and Connect AC

optimization guidelines - accessibility ericsson - rev01

Documents

s cs s

s ps s

ucs s

ups s

o success rate cs

o success rate ps

setup success rate cssr

cs cssr