USER DESCRIPTION 208/1553-HSC 103 12/14 Uen A
UserDescription,GSM-UMTSCellReselectionandHandover
Copyright
CopyrightEricssonAB,2008.AllRightsReserved.
Disclaimer
Nopartofthisdocumentmaybereproducedinanyformwithoutthewrittenpermissionofthecopyrightowner.
Thecontentsofthisdocumentaresubjecttorevisionwithoutnoticeduetocontinuedprogressinmethodology,designandmanufacturing.
Ericssonshallhavenoliabilityforanyerrorordamagesofanykindresultingfromtheuseofthisdocument.
Trademark List
Ericsson isatrademarkownedbyTelefonaktiebolagetLMEricsson.
AllotherproductorservicenamesmentionedinthisUserDescriptionaretrademarksoftheirrespectivecompanies.
Contents
1 Introduction1.1 General1.2 ReadersGuide1.3 MainChangesinEricssonBSS08A1.4 MainChangesinEricssonBSS08B1.5 MainChangesinEricssonBSS09A2
Capabilities
3
Technical Description
3.1 General3.2 Measurements3.3 Inter-RATfunctions3.4 RelatedStatistics4
Engineering Guidelines
4.1 Multi-RATMSCapabilities4.2 SystemInformation4.3 CellReselectiontoUMTS4.4 Intersystemcellselectionaftercallrelease4.5 InterSystemHandover5
Parameters
5.1 General5.2 MainControllingParameters5.3 ValueRangesandDefaultsValues6
Concepts
Glossary
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Reference List
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1 Introduction
1.1General
ThisuserdescriptiondescribesanumberoffeaturesrelatedtohandoverbetweenGSMandUMTS.ThefeaturesdescribedareGSM-UMTSCellReselectionandHandover,SmoothGSMtoWCDMAUnloading,HandoverwithUsageofServiceIndicator,CombinedCellReselectionTriggeringGSMtoWCDMA,CombinedHandoverTriggeringGSMtoWCDMAandOptimizedthroughputatGSMtoWCDMACellChange(basedonNC2).
ThefeatureGSM-UMTSCellReselectionandHandoverallowsend-userswithMulti-RAT(RadioAccessTechnology)GSM/WCDMAMobileStationstoroambetweenUTRAN(UMTSTerrestrialRadioAccessNetwork)andGSMradioaccessnetworkwithoutlossofservice(providedtheserviceissupportedinbothnetworks).Itgivessupportformobilityinidlemode(GSMtoUTRAN),forhandoverofcircuitswitchedconnections(GSMtoUTRAN),andforcellreselectionforpackedswitchedservice(GPRS/EGPRStoUTRAN).
ThefeatureSmoothGSMtoWCDMAUnloadinghelpsassuringresourceavailabilityinGSMcellsandlimitshandoverloadathighloadsituations.
ThefeatureHandoverwithUsageofServiceIndicatorgivessupportforservicebasedhandovers,whichmeanstheMSCcangivepreferencetowhichradioaccessnetworktouseforaconnection,GSMorWCDMA.TheServiceIndicatorisusedbytheBSCwhendecidingonCShandoverfromGSMtoWCDMA
ThefeatureCombinedCellReselectionTriggeringGSMtoWCDMAprovidesthepossiblitytodefineathresholdforCPICHRSCPmeasurementstobeusedatcellreselection.ThethresholdforCPICHRSCPmeasurementsassuresasufficientdownlinksignalstrength,whichinturnincreasesthepossiblityforthemobiletoreachthenetworkintheuplink.
ThefeatureCombinedHandoverTriggeringGSMtoWCDMAprovidesthepossibilitytodefineaCPICHRSCPthresholdusedtocontrolthemeasurementreportingofUTRANcellsforMSsbeinginconnectedmodeorforMSsbeinginNC2mode.NoUTRANcellswillbeincludedinthemeasurementreportsfromtheMSunlessthenonreportingradioentity(CPICHRSCP)haveavalueabovethedefinedCPICHRSCPthreshold.
ThefeatureOptimizedthroughputatGSMtoWCDMACellChangeimprovesend-userperformancebypreventingacellreselectionfromaGSMcelltoaWCDMAcellwhichinsomeinstancescanhaveoutagetimesof10|20secondsontheend-userapplicationlevel.
ThisdocumentonlydescribestheBSSfunctionality,notUTRANparts,ofcircuitandpacketswitchedintersystemcellreselectionandhandover.OnlyWCDMAFDD(FrequencyDivisionDuplex)issupported.
ThefeatureFastReturntoWCDMAafterCallReleaseisintroducedtodecreasethePagingOutageTime.Withthefeaturemulti-RATmobilescanberequestedtoselectaWCDMAcelldirectlyafterthecallreleaseandhencepreventingthemobiletofirstselectaGSMcellandthenre-selectaWCDMAcell.
ThefeatureQueuingofWCDMACallsinBSSmakesitpossibletoprovideenhancednetworkaccessibilityinGSMtoprioritizedsubscriberscomingfromtheWCDMAnetworkviathedirectedretryprocedure.
1.2ReadersGuide
ThisdocumentdescribestheGSMandUMTSinterworkingfromaBSSperspective.UMTSdetailscanbefoundinthedocumentationdescribingtheWCDMARadioAccessNetworkproduct.
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1.3MainChangesinEricssonBSS08A
Nochanges.
1.4MainChangesinEricssonBSS08B
Nochanges.
1.5MainChangesinEricssonBSS09A
ThefeatureQueuingofWCDMACallsinBSShasbeenintroduced.ThefeatureFastReturntoWCDMAafterCallReleasehasbeenintroduced.
2Capabilities
WiththefeatureGSM-UMTSCellReselectionandHandover,anoperator(ortwooperators)ofbothaGSMandaUTRANsysteminanareacanusethesenetworkstocomplementeachother.Forexample,thealreadybuiltoutcoverageofGSMcanbeused,sothatend-userswithMulti-RATMSswillexperiencegoodcoveragealsoinareaswherethereisnoUTRANcoverageusingtheUMTStoGSMcellreselectionandhandoverfunctionality.Thiswillincreasetheserviceperceivedbyend-usersaswellasthecombinednetworkcapacity.
WiththefeatureHandoverwithUsageofServiceIndicator,thefeatureGSM-UMTSCellReselectionandHandoverisextendedwithamechanismthatenablestheMSCtoaffectwhichradioaccessnetwork,GSMorWCDMA,preferablyshallserveaCSconnection.
WiththefeatureSmoothGSMtoWCDMAUnloading,thefeatureGSM-UMTSCellReselectionandHandoverisextendedwiththepossibilitytolimitthemaximumnumberofhandoverstoperformpersecondtoUTRAN.OnlythenumberofhandoversthataretriggeredbecauseofhightrafficloadintheGSMcellarelimited.Furthermore,incominghandoversfromUTRAN,willberejectedincaseofhightrafficloadintheGSMcell.ThesemechanismshelpstoassuretheresourceavailabilityintheGSMnetwork.
WiththefeatureCombinedCellReselectionTriggeringGSMtoWCDMA,cellreselectionisimprovedtodecreasethenumberofping-pongcellreselections.ThatisachievedbyaddingathresholdforCPICHRSCPmeasurementstoassureasufficientdownlinksignalstrength,whichinturnincreasesthepossiblityforthemobiletoreachthenetworkintheuplink.
WiththefeatureCombinedHandoverTriggeringGSMtoWCDMA,theIRAThandoverbehaviourisimprovedbyavoidinghandoverattemptstoweakUTRANcells.ThatisachievedbyaddingareportingthresholdfornonreportingradioentityoftheUTRANcells.SinceCPICHEc/NoisthereportingradioentitythenonreportingradioentityisCPICHRSCP.AnMSwillonlyincludeaUTRANcellinthemeasurementreportsincasetheCPICHRSCPvalueoftheUTRANcellisabovethedefinedthresholdvalue.ThisassuresthatUTRANhandovercandidateshaveasufficientdownlinksignalstrength,whichinturnincreasesthepossiblityforthemobiletoreachthenetworkintheuplink.
WiththefeatureOptimizedthroughputatGSMtoWCDMACellChange,end-userperformanceisimprovedforGPRS/EDGE/WCDMAsubscribers.Inparticular,thisfeaturereducestheimpactondownloadtimesbyprohibitingacellreselectionfromaGSMcelltoaWCDMAcell,andthusavoidingthelongoutagetimes,whenanMSisinpackettransfermode.
WiththefeatureFastReturntoWCDMAafterCallRelease,thePagingoutagetimecanbedecreasedsincethemulti-RATmobilescanberequestedtoselectaWCDMAcelldirectlyatthecallreleasewhichpreventsthemobiletofirstselectaGSMcellandthenre-selectaWCDMAcell.
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ThefeatureQueuingofWCDMACallsinBSSmakesitpossibletoprovideenhancednetworkaccessibilityinGSMtoprioritizedsubscriberscomingfromtheWCDMAnetworkviathedirectedretryprocedure.
3TechnicalDescription
3.1General
ThefeatureGSM-UMTSCellReselectionandHandoverprovidesthebasicmechanismsforhandoverandcellreselectionfromGSMtoUMTS.Parameterscanbesettocontrolwhenamulti-RATMSinidleorconnectedmodeshallstartmeasuringonUTRANcells,seeSection3.2.AUTRANcellwillonlybeconsideredasacandidateforcellreselectionorahandoverifthesignalqualityinthetargetcellisgoodenough.PrioritizingofUMTSorGSMcanbecontrolledbyseveralparameters.CellreselectionandtheoptionalfeatureCombinedCellReselectionTriggeringGSMtoWCDMaredescribedinSection3.3.2.Forhandover,thetrafficloadoftheGSMcellcaninadditiontotheradiocriteriabeusedasacriterionforhandoverstowardsUMTS,seeSection3.3.4.
WiththeoptionalfeatureCombinedHandoverTriggeringGSMtoWCDMAitisfurtherpossibletocontroliftheMSshallincludeUTRANcellsinthemeasurementreportssenttothenetwork.OnlyUTRANcellswithCPICHRSCPvaluesaboveagivenCPICHRSCPthresholdwillbeincludedinthemeasurementreports.
IncasetheurgencycriteriaintheGSMcellarefulfilled,seeReference[4],handovertoUTRANmaybetriggeredregardlessofthetrafficloadintheGSMcell.
WiththefeatureHandoverwithUsageofServiceIndicator,thefeatureGSM-UMTSCellReselectionandHandoverisextendedwithamechanismfortheMSCtocontrolinwhichsystem(GSMorUMTS)aconnectionpreferablyshallbeserved.IftheMSCindicatesthataconnectionshallnotbehandedovertoUTRAN,BSSnevertriggersahandovertoUTRAN.IftheMSCindicatesthataconnectionshouldnotbehandedovertoUTRAN,BSSonlytriggersahandovertoUTRANincaseanyurgencycriterionisfulfilledintheGSMcellandwhenthesignalqualityinthetargetcellisgoodenough.IncasetheMSCindicatesthatahandovershouldbeperformed,BSStriggersahandovertoUTRANwhenthesignalqualityinthetargetcellisgoodenough.
WiththefeatureSmoothGSMtoWCDMAUnloading,thefeatureGSM-UMTSCellReselectionandHandoverisextendedwiththepossibilitytolimitthemaximumnumberofhandoverstoperformpersecondtoUTRAN.OnlythenumberofhandoversthatistriggeredbecauseofhightrafficloadintheGSMcellislimited.Furthermore,incominghandoversfromUTRAN,willberejectedincaseofhightrafficloadintheGSMcell.
WiththefeatureOptimizedthroughputatGSMtoWCDMACellChange,end-userperformanceisimprovedforGPRS/EDGE/WCDMAsubscribers.Inparticular,thisfeaturereducestheimpactondownloadtimesbyprohibitingacellreselectionfromaGSMcelltoaWCDMAcell,andthusavoidingthelongoutagetimes,whenanMSisinpackettransfermode.ThisfeatureisbasedonNC2,seeReference[3].
ThefeatureFastReturntoWCDMAafterCallReleaseisintroducedtodecreasethePagingoutagetime.Withthefeaturemulti-RATmobilescanberequestedtoselectaWCDMAcelldirectlythecallreleaseandhencepreventingthemobiletofirstselectaGSMcellandthenre-selectaWCDMAcell.
ThefeatureQueuingofWCDMACallsinBSSmakesitpossibletoprovideenhancednetworkaccessibilityinGSMtoprioritizedsubscriberscomingfromtheWCDMAnetworkviathedirectedretryprocedure.
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3.2Measurements
BesidesmeasurementsonsurroundingGSM/GPRS/EGPRScellsaMulti-RATMSalsoperformsmeasurementsonUTRANneighbouringcells.ThesemeasurementsareperformedinadifferentwaythanforGSMcellsandmaybelessfrequentlythanmeasurementsonGSM.IngeneralUTRANmeasurementsaredoneduringsparetime,thatis,GSMmeasurementshavepriorityandUTRANmeasurementsaredoneifthereistimeleft.
InordertoreduceunnecessarymeasurementsandtooptimizeMulti-RATMSbatteryconsumption,theGSMnetworkcontrolswhenthemeasurementsonUTRANcellsshallbeperformedwiththeparametersQSIandQSC.TheparametersQSIandQSCdefinethresholdsandalsoindicatewhetherthesemeasurementsshallbeperformedwhenthesignalstrength(SS)oftheservingcellisbeloworabovethethreshold.ItcanbeusedtoavoidunnecessarymeasurementsonUTRANcellsanddoesnotcontrolthebehaviourofMulti-RATMSsintermsofmakingdecisionsforcellreselectionandhandover.QSIisusedforidleandpacketswitchedmodesandbroadcastonBCCHandPBCCH(ifenabled),whileQSCisusedforactivemode,sentonSACCH.
Afterchangingfromidletoactivemode,QSCisnotimmediatelyknown,asitissentonSACCH.Forthatperiodthemeasurementcontrolisdefined,withthecellparameterQSCI,broadcastonBCCH.ItispossibletochoosewhetherUTRANmeasurementswillbeperformedaccordingtotheknownQSIvalue(QSCI=0)oralways(QSCI=1),untilthefirstQSCvalueisread.
Therearefourdifferentscenariostochoosefrom.ParametersQSIandQSCaresetperGSMcellanddefineboththescenarioandthenecessarythreshold,atthesametime:
UTRANneighbouringcellsaremeasuredonlywhenthesignalstrengthoftheGSMservingcellisabovethethresholdsetbyQSIandQSC.
1.
UTRANneighbourcellsaremeasuredonlywhenthesignalstrengthoftheGSMservingcellisbelowthethresholdsetbyQSIandQSC.
2.
UTRANneighbourcellsarealwaysmeasured.3.
UTRANneighbourcellsarenevermeasured.Thiscanbeusedtoturnoffthecellreselection/handovertoUMTS,percell,evenifCOEXUMTSisONfortheBSC.
4.
InordertounderstandthepurposeofQSIandQSC,twoexamplesareshowninFigure1andFigure2.
WhenQSI/QSC=5,UTRANcellmeasurementsareperformedwhentheSSoftheservingGSMcellisbelowthethresholdof-78dBm,seeFigure1.
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Figure1ExampleQSI/QSC=5,UTRANMeasurementsArePerformedwhentheSignalStrengthintheServingCellIsbelow-78dBm.
WhenQSI/QSC=11,themeasurementsareperformedwhenthesameSSisabovethethresholdof-66dBm,seeFigure2.
Figure2ExampleQSI/QSC=11,UTRANMeasurementsArePerformedWhentheSignalStrengthintheServingCellIsabove-68dBm.
Example1:IfanUTRANcellshouldservepurelytoextendthecoverageforMulti-RATMSsinGSM,itislogicaltosetQSI/QSCvaluesfrom0-6,sinceit'sonlyneededtomakecellreselectionandhandoverstoUMTSwhentheGSMcoveragefallslow.
Example2:IfanUTRANcellisco-sitedwithaGSMcell,thereisacertaincorrelationbetweensignalstrengthsofthetwosystems.IftheGSMisforexampleusing900MHzbanditisveryprobablethattheGSMsignalstrengthwillalwaysbehigherthantheUTRANsignal,foranumberofdBs.Therefore,thereisnopointinmeasuringUTRANcellsinlowGSMsignalconditionsandvalues8-14canbeselectedaccordingly.
WheninCSactiveorpackettransfermodeaGSM/GPRS/EGPRSMScontinuouslymeasuresthesignalstrengthoftheservingcellandallneighbouringcells(BCCHcarriers)asindicatedintheBAlist.Besides,theGSM/GPRS/EGPRSMSshallattempttodecodetheBSICofasmanyneighbouringcellsbelongingtotheBAlistaspossible,andasaminimumatleastonceevery10secondsduringthesocalledsearchframes.TheMSistypicallyquitebusywithperformingGSM/GPRS/EGPRSmeasurementandthereisnotmuchtimeleftforUTRANmeasurements.Inthiscase,theMSmayperformthemeasurements,oncellsbelongingtothe3Gneighbouringcelllist,duringsearchframesthatarenotrequiredforBSICdecoding.IfindicatedbytheparameterSPRIO,aMulti-RATMSmayuseupto25searchframesper13secondsevenwithoutconsideringtheneedforBSICdecodingintheseframes.ThisimpliesmoretimeforUTRANmeasurements,butinthesamewaylesstimeforBSICdecoding.
3.3Inter-RATfunctions
3.3.1 PLMN Selection
WhenaMulti-RATMSispoweredonoruponrecoveryfromlackofcoverage,itimmediatelyattemptstomakecontactwithaPublicLandMobileNetwork(PLMN).ThePLMNmaybeselectedeitherautomaticallyormanuallysimilartoaGSMonlyMS(seeReference[2]).ThePLMNselectionprocedureissomewhatdifferentforaMulti-RATMSsinceaPLMNcouldsupportmorethanoneaccesstechnology.ItwillfirsttrytoselectandregistertothelastregisteredPLMNifoneexists.AMulti-RATMSstartsitssearchusingthelastusedRAT.If
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informationaboutthelastusedRATisnotavailable,theMulti-RATMSstartsitssearchusingGSMaccesstechnology.IfthereisnolastregisteredPLMN,orifitisunavailable,theMulti-RATMSwilltrytoselectanotherPLMNeitherautomaticallyormanuallydependingonitsoperatingmode,seeReference[10].TheautomaticmodeusesalistofPLMNsandRATsinanorderofprioritywhereasthemanualmodeleavesthedecisiontotheend-userandonlyshowstheavailablePLMNsusingallsupportedRATs.
IfaPLMNisselectedusingGSMaccesstechnologythefollowingcellselectionandcellreselectionproceduresaredescribedinReference[2].Multi-RATproceduresinUTRANarenotdescribedinthisdocument.
3.3.1.1AutomaticMode
Inautomaticmode,ifnolastregisteredPLMNexistsorisavailabletheMSwillselectaPLMN,ifitisavailableandallowed,inthefollowingorder:
HomePLMN.TheMulti-RATMSshallsearchfortheHomePLMNusingallaccesstechnologiesitiscapableofandstartitssearchusingthe"accesstechnologiesprioritylist"storedintheSubscriberIdentityModule(SIM).IfnoaccesstechnologyinformationisavailableintheSIMthemobileshallstartitssearchusingGSMaccesstechnology.
1.
EachPLMNinthe"usercontrolledPLMNlist"storedintheSIMinpriorityorder.TheMulti-RATMSshalltryfindeachPLMNusingthe"accesstechnologiesprioritylist"storedforeachPLMNintheSIM.IfnoaccesstechnologyinformationisavailableontheSIMthemobileshallstartitssearchusingGSMaccesstechnology.
2.
EachPLMNinthe"operatorcontrolledPLMNlist"storedintheSIMinpriorityorder.TheMulti-RATMSshalltryfindeachPLMNusingthe"accesstechnologiesprioritylist"storedforeachPLMNintheSIM.IfnoaccesstechnologyinformationisavailableontheSIMthemobileshallstartitssearchusingGSMaccesstechnology.
3.
OtherPLMN/accesstechnologycombinationswithreceivedhighqualitysignalinrandomorder.ForGSMcellshighqualitycellsarecellswithsignallevelabove-85dBm.ForWCDMAcellshighqualitycellsarecellswithCPICHRSCPlevelabove-95dBm.TheMulti-RATMSshallsearchusingallaccesstechnologiesitiscapableofbeforeselectingPLMN.
4.
AllotherPLMN/accesstechnologycombinationsinorderofdecreasingsignalstrength.TheMulti-RATMSshallsearchusingallaccesstechnologiesitiscapableofbeforeselectingPLMN.
5.
3.3.1.2ManualMode
Inmanualmode,theMulti-RATMSwillfirsttrytoselecttheregisteredPLMNorhomePLMNifnolastregisteredPLMNexists.IfthisregistrationfailsoriftheuserhasinitiatedaPLMNreselectiontheMulti-RATMSwillindicatetotheuserallavailablePLMNsusingallsupportedaccesstechnologies.TheusercanthenselectadesiredPLMNwhichcausestheMStoinitiatearegistrationonthisPLMN.IftheselectedPLMNisnotallowed,anindicationtotheusertoselectanotherPLMNwillbegiven.
Note:AnMulti-RATMSmayindicateaccesstechnologytotheuser(manufacturerdependent).IftheaccesstechnologyisnotdisplayedthehighestaccesstechnologyaccordingtotheaccesstechnologyinformationprioritylistintheSIMisused.
3.3.2 Inter System Cell Reselection
3.3.2.1CellReselectiontoGSM
ThereisnosignificantimpactofcellreselectionfromUMTStoGSMontheBaseStationSystem.Ingeneral,cellreselectionfromUMTStoGSM/GPRS/EGPRSisintroducedwithaslittlechangeaspossibletotheGSMstandard.
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ThecellreselectionisinitiatedinUTRANandnotdescribedhere.Inshort,foranintersystemcellreselectiontooccurtheestimatedqualityofthecurrentlyusedUTRANfrequencymustbebelowacertainthresholdandtheestimatedqualityofthetargetGSMcellmustbeaboveacertainthreshold.SeeReference[15]foradescriptionofUMTStoGSM/GPRS/EGPRScellreselectioninEricssonWCDMARAN.
WhenaMulti-RATMSmovesintoacellbelongingtoanotherLA/RAatcellreselectionfromUMTStoGSM/GPRS/EGPRSitperformsLA/RAUpdateRequest,whenaccessingtheGSMnetworkusingexistingsignalingprocedurestoindicateitspresenceaccordingtoSection3.3.5andSection3.3.6.ThetargetBSCwillnotdistinguishifthemobilecamefromaGSMorUTRANcellbeforethecellreselection.
3.3.2.2CellReselectiontoUMTS
ThisalgorithmisvalidforMSsinNC0orNC1mode.ForMSsinNC2mode,refertoReference[3].
TobeabletoperformintersystemcellreselectionfromGSMtoUMTS,aMulti-RATMSlistenstoadefinedlistofUMTSneighbours.ThislistisbroadcastonBCCH(andPBCCHifenabled).AsimilaralgorithmtotheoneforGSMcellreselectionisusedforGSMtoUTRANcellreselection.Nevertheless,thereisadifferencewhenitcomestotheevaluationofsignalstrengthandqualityforGSMandUMTSmeasurements.Thereasonforthisisthecompletelydifferentmodulationtechniqueused.Therefore,amappingofUMTSsignalstrengthisperformed,insuchawaythatitcanbecomparedtoGSMsignalstrengthvalues.ThesamealgorithmandbehaviourappliesforintersystemcellreselectioninGPRS/EGPRSReadystate,GPRS/EGPRSStandbystateandCSidlemode.
ThealgorithmforintersystemcellreselectiontoUMTSiscontrolledbythenetworkwiththeparametersFDDQMINandFDDQOFF.
FDDQMINistheminimumqualityofaUTRANcellforcellreselection.Thisparametershouldnotbeusedtocontrolthecellreselection,butprovideasufficientqualityofthecandidateUTRANcell.
FDDQOFFisthekeyparametertocontrolthebehaviourofintersystemcellreselection.ItdefinesanoffsetbetweensignalqualityofUTRANandGSMcells.
LowervaluesoftheparameterFDDQOFFcanbeusedtooff-loadtheGSMsystem.Thismeansthatbothpotentialtraffic(Multi-RATMSsinCSidlemodeandGPRS/EGPRSpacketidlemode)andresourceoccupyingtraffic(Multi-RATMSsinGPRS/EGPRSpackettransfermode)willselectaUTRANcellthatfulfillstheintersystemcellreselectioncriteria.
HighervaluesoftheparameterFDDQOFFcanbeusedtokeepMulti-RATMSsintheGSMsystem,forexampleifanUMTStoGSMoff-loadprioritysettingisappliedintheUMTSsystem.
ThevaluesoftheGSMsignalstrengthandtheUTRANCPICHRSCParenotofthesamekindandthereforenoteasilycomparable.ThebalancebetweenthesetwoshouldbesetwiththeoffsetFDDQOFF.
TheBSSparametersFDDQMINandFDDQOFFmustbesetincorrelationtothecorrespondingUTRANparameterstoavoidunwantedbehaviour,suchas|ping-pong|effect.
NotethatthesettingoftheparameterQSIindirectlyrestrictsthecontrolofcellreselection,sincenocellreselectionwillbemadewithoutUTRANmeasurements.
IfthefollowingcriteriaarefulfilledaMulti-RATcapableMSwillreselectasuitableUTRANcell(seeReference[11]):
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CPICHEc/No>FDDQMIN (1)
and
CPICHRSCP>RLA(s+n)+FDDQOFF (2)
foraperiodof5seconds.(s+n=servingandneighbouringGSMcells)
CPICHEc/NoisthereceivedenergyperchipontheCommonPilotChannel(CPICH)dividedbythepowerdensityintheband.ThisquantitymeasuresthequalityoftheneighbouringUTRANcells(roughlycomparabletoasignaltonoiseratiomeasure).Tofulfillthefirstcriterion,itmustexceedthethresholdparameterFDDQMINsetintheBSCandbroadcasttoMulti-RATMSsontheBCCHandPBCCH(ifenabled).
CPICHRSCPisameasureofthesignalstrengthforaUTRANcell.Tofulfillthesecondcriterion,itmustexceedtheRLA(measuredsignalstrength)forboththeservingcellandthe6strongestnon-servingGSM/GPRS/EGPRScellswithanoffsetdefinedbytheparameterFDDQOFF.IfmorethanoneUTRANcellfulfillsthesecriteria,theMulti-RATMSselectstheonewithhighestCPICHRSCP.
RLA(ReceivedLevelAverage)istheaverageofthereceivedsignallevelsmeasuredindBmforallmonitoredGSMfrequenciesintheBAlist.TheaveragingisbasedonatleastfivemeasurementsamplesperRFcarrierspreadover3to5seconds,themeasurementsamplesfromthedifferentRFcarriersbeingspreadevenlyduringthisperiod(seeReference[8]).RLA=RLA_CforGSMattachedMulti-RATMSsandRLA=RLA_PforGPRS/EGPRSattachedMulti-RATMSs.
CellreselectionbacktoUTRANshallnotoccurwithin5secondsafterapreviouscellreselectionfromUTRAN.Ifacellreselectionoccurredwithintheprevious15seconds,anadditionaloffsettoFDDQOFFisincreasedby5dBbythemultiRATMS.
NotethatifthecriteriaforintersystemcellreselectiontoUMTSarefulfilled,theMulti-RATcapableMSreselectsaUTRANcellevenifthecriteriaforselectingaGSM/GPRS/EGPRScellisfulfilled.AGPRS/EGPRSMulti-RATMSusesthesamecellreselectionalgorithminpacketidlemode(noongoingpackettransfer)andinpackettransfermode.
3.3.2.3CombinedCellReselectionTriggeringGSMtoWCDMA
WiththefeatureCombinedCellReselectionTriggeringGSMtoWCDMA,amulti-RATmobilewillreselectaUTRANsuitablecellifcellreselectioncriteria(2),alongwith(3)and(4)belowarefulfilled:
CPICHEc/No>FDDQMIN - FDDQMINOFF (3)
and
CPICHRSCP>FDDRSCPMIN - min((P_MAX-21 dBm),3dB) (4)
Withcriterion(3),therequirementofsignalqualitycanbemadelessrestrictiveformulti-RATmobilesthatsupportssignalstrengthcriterion(4).P_MAXisthemaximumRFoutputpoweroftheMS(dBm)inUTRANFDD.
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3.3.2.4OptimizedthroughputatGSMtoWCDMACellChange
ThisfeatureisactivatedbysettingtheparameterNCPROFavalueof1.
ThisfeatureonlyaffectsMSsinpackettransfermodehavingDL/ULTBFwithpayloaddata.ThisfeaturewillnotaffectanMSinDTMmode,i.e.whentheMSisbothinpackettransfermodeandcircuitswitcheddedicatedmode.
Thisfeaturewillengagewhenthefloowingcriteriaarefulfilled:
ThereisatleastoneWCDMAneighbouringcelltotheservingcell.1.
AdownlinkTBFwithpayloaddatahasbeenestablished.2.
TheTBFsession(UL,DLorboth)islongerthan2seconds.3.
ThecurrentRPloadpermitsanotherMSinNC2mode.4.
TheMSisnotinDTMmode5.
FromthetimeatestablishmentofthedownlinkTBFwithpayloaddata,adelaytimeof2secondsisappliedbeforeaffectingtheMSasstatedincriteria(3)above.ThereasontohaveadelayistofilterouttheshortTBFsessionsandtominimizetheloadonthesignallingchannel.
Oncethecriteriaabovearefulfilled,theMSisorderedtoNC2modeandthenetworkcellreselectionalgorithmisinitiated.ThenetworkcellreselectionalgorithmissimilartothecellreselectionalgorithmintheMSasdescribedinReference[8]andSection3.3.2.2andisdescribedmoreindetailinReference[3].
AfteranMSisinstructedtoperformacellreselectiontoanewcell,itisthenorderedtoleaveNC2asdescribedinReference[14].AftertheMShasenteredthenewcell,itwillnotbeabletochangetoanothercellduringthefirst5seconds.DuringthisperiodoftimetheMSmaybeorderedtoNC2againinthenewcellbeforeitcanmakeanydecisionregardingcellchange,forexample,toaWCDMAcell.
3.3.3 Inter system cell selection after call release
WhenthefeatureFastReturntoWCDMAafterCallReleaseisactivated,theBSCmightrequesttheMStoselectaWCDMAcelldirectlyafterthereleasewithoutfirstselectingtheservingGSMcell.ThatisdonebyincludingtheIE"CellselectionindicatorafterreleaseofallTCHandSDCCH"intheCHANNELRELEASEmessage.TheBSCdoesnotindicateanyindividualWCDMAcellbutonlyindicatesthefrequencynumber(s),theUARFCN(s).
IftheGSMcellhasbeenconfiguredwithanActiveUTRANMeasurementFrequencyList,theBSCwilldirectamobiletoUTRANwhenthefollowingcriteriaarefulfilled:1.Thefeatureisactivated2.ThemobileshallnotbecomeaVGCSlistener3.TheparameterQSChasnotbeensetto|never|4.MShasreportedmeasurementsonaUTRANcellwhileindedicatedmode(thereisUTRANcoverage)
TheBSCwillonlyrequestthemobiletoselectafrequencyreportedbythemobileinthemeasurementreport.
IftheGSMcellhasonlybeenconfiguredwithanIdleUTRANMeasurementFrequencyListorQSCissetto|never|,themobilewillnotreportanymeasurementsonUTRANcellsandtheBSCwilldirectthemobiletoUTRANwhenfollowingcriteriaarefulfilled:1.Thefeatureisactivated.2.ThemobileshallnotbecomeaVGCSlistener.3.TheMSisamulti-RATmobile
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SincethemobiledoesnotincludeanyWCDMAcellsinanymeasurementwhennoActiveUTRANMeasurementFrequencyListhasbeendefinedortheQSCparameterissetto15(=never),theBSCwillinthiscaserequestthemobiletoselectafrequencyincludedfromtheIdleUTRANMeasurementFrequencyList.
Inthelatterscenario,whenthereisnoActiveUTRANMeasurementFrequencyListortheQSCissetto15(=never),thereisariskthatthemobilewillbere-directedtoWCDMAeventhoughthereisnoWCDMAcoverage.ThemobilewillthenunsuccessfullysearchforWCDMAcellsandafterawhileselectaGSMcell.Insuchacase,thePagingoutagetimewillinsteadincrease.ThereforeitisrecommendedtoturnoffthefeatureinGSMcellswheretheUTRANcoverageispoorandwhennoActiveUTRANMeasurementFrequencyListhasbeenconfigured.
IftheparameterQSIissetto15(=never),meaningthatmobileshouldnotmeasureonWCDMAcellswhileinidlemode,thefeaturecouldbeturnedoffinordertonotrequestthemobiletoselectaWCDMAcell.
ThemobilewillberequestedtoselectaWCDMAcellalsoiftheCSconnectionofaDTMcallisreleased.TheinterruptofthepacketdatatransferwillbeshorterifthemobileinsteadisrequestedtoenterNC2inGSM.WiththeparameterFASTRET3GNC2itispossibletochangethebehaviorsothatthemobileisnotrequestedtoselectaWCDMAcellifthefeatureOptimizedthroughputatGSMtoWCDMACellChangeisactiveandtheCSconnectionofaDTMcallisreleased.
3.3.4 Inter System Handover
3.3.4.1HandovertoGSM
ThebasisforUMTStoGSMhandoverdecisionsisimplementedintheRadioNetworkController(RNC)intheUTRANsystem.ThealgorithmforUMTStoGSMhandoverinitiationinEricssonWCDMARANisdescribedinReference[16].Inshort,thehandovercriterionisbasedonthefollowingevent:estimatedqualityofthecurrentlyusedUTRANfrequencyisbelowacertainthresholdandtheestimatedqualityofthetargetGSMcellisaboveacertainthreshold.
DuringhandoverexecutiontheBSCisinformedviatheMSCthatanintersystemhandoverisrequired.ThetargetBSCallocatesresourcesandorderstheMulti-RATMStoaccessthetargetGSMcellviatheservingRNC.TheBSCwillnotdistinguishbetweenincomingintra-orintersystemhandovers.
WiththefeatureSmoothGSMtoUMTSUnloading,incomingintersystemhandoverswillbetreateddifferently,seeSection3.3.4.4.
3.3.4.2HandovertoUMTS
ThischapterdescribesthebasichandovermechanismprovidedbythefeatureGSM-WCDMACellReselectionandHandover.Thesebasicmechanismismodified/complementedbyotherfeatures,describedinSection3.3.4.3,Section3.3.4.4andSection3.3.4.5.
Incircuitswitchedactivemode(speechanddata),aMulti-RATMSismeasuringneighbouringUTRANcellsandreportingtotheBSSthroughmeasurementreports.TobeabletoperformintersystemmeasurementsalistofUTRANneighboursissenttotheMulti-RATMSontheSACCH.TheselistscanbethesameasthelistbroadcastonBCCHtoMulti-RATMSsinidlemode,butitisalsopossibletosetthemseparatelyinordertohavedifferentUMTSneighboursinidleandactivemode.Afterchangingfromidletoactivemode,thelastlistreceivedoverBCCHisused(thatis,Idle3G-BA),untilanewoneisreceivedoverSACCH(thatis,active3G-BA).TheMulti-RATmobileisinformedonhowmanyUMTScells(0-3)thatshallbereportedinthemeasurementreport.ThisissetbyparameterFDDMRR.BSSinformsthemobilewhichmeasurementreporttouse,MeasurementReportorEnhanced
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MeasurementReport.Belowfollowsabriefdescriptionofhowthemobilescomposethedifferentmeasurementreports.
Measurementreporttypeis|MeasurementReport|
WhentheMeasurementReportisused,themulti-RATMSwillcomposethelistasfollows:
1.AddMIN(FDDMRR,numberofvalidUTRANcells)UTRANcellstothetopofthelist.
2.AddMIN((6-numberofaddedUTRANcells),numberofvalidGSMcells)GSMcellstothelist.
3.Ifthereismorespaceinthemeasurementreport,addremainingvalidUTRANcells.
NotethatifmultipleGSM-bandsareused,therewillbefewpositionsinthemeasurementreportforcellsfromthosebands,sinceonlysixcellscanbereportedinthemeasurementreport.FormoreinformationonMultibandoperation,seeReference[6].
AlsonotethatifFDDMRRissetto0andifthenumberofvalidGSMcellsarenotenoughtofillthelist,UTRANcellsmaybereported.
UTRANneighbouringcellsarereportedreusingthefieldsdefinedforGSMneighbouringcellsmeasurements.
ForGSMneighbourcells,theRXLEVfieldisasusualcodedasthebinaryrepresentationofthereceivedsignalstrengthontheneighbouringcell.ForUTRANneighbourcells,theRXLEVfieldisinsteadcodedasthebinaryrepresentationofCPICHEc/No(definedinReference[8]).
ForGSMneighbourcells,theBCCH-FREQfieldisasusualcodedasthebinaryrepresentationofthemeasuredcell'spositionintheBAlist.ForUTRANneighbourcells,theBCCH-FREQfieldisalwayscodedas31(binary).ThismeansthatthemaximumnumberofGSMneighbouringcellsisreducedfrom32to31incellshavingUTRANneighbouringcellsdefined.
AUTRANcellisuniquelyidentifiedwithitsfrequencyandscramblingcodecombinationsothereisnoequivalenttoBSICforGSMcells.InthefieldwhereBSICisusuallyreportedforGSMcells,thebinaryrepresentationofthemeasuredUTRANcell'spositionintheactive3G-BAlistiscoded.
Measurementreporttypeis|EnhancedMeasurementReport|
WhentheEnhancedMeasurementReportisusedthemulti-RATMSwillcomposethelistinthefollowingpriortyorder:
1.Fromservingband,addMIN(3,numberofvalidGSMcells)GSMcellstothelist.
2.Fromeachnon-servingband,addMIN(MBCR,numberofvalidGSMcells)GSMcellstothelist.
3.AddMIN(FDDMRR,numberofvalidUTRANcells)UTRANcellstothelist.
4.IfpossibleaddremainingGSMcellsandUTRANcells.ThecellstoincludeareselectedbytheMS.ThecellsarerankedbycomparingRXLEVforGSMcellswithCPICHRSCPforUTRANcells.
NotethatthereisariskthatthemobilewillnotreportthenumberofUTRANcellsasindicatedbyFDDMRR.HoweverwhenUTRANcellsarereported,theBSCwillalwaysevaluateMIN(FDDMRR,numberofvalidUTRANcells)numberofUTRANcellswhenproducingthefinalhandovercandidatelist.
UponreceivingthemeasurementsfromaMulti-RATMS,theBSCisperformingthelocatingalgorithminordertocreateacandidatelistforhandovers.MeasuredUTRANandGSMcellsareprocessedseparately.ThisisdonebyfilteringouttheUTRANcellmeasurementsbeforeapplyingtheGSMlocatingalgorithm.
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TheGSMlocatingalgorithmismodifiedinordertoprocessbothUTRANandGSMneighbouringcells,asshownontheFigure3.
Figure3ModifiedLocatingAlgorithm.MeasurementfromUMTSandGSMCellsAreProcessedSeparatelyandUTRANCellsAreAddedtotheGSMList
TheexistingGSM-GSMlocatingalgorithmiskeptintact.Paralleltothat,aGSM-UMTSalgorithmranksUTRANneighbourcellsandaddspossiblecandidatestothecompletecandidatelist.ForfilteringGSMmeasurements,differentfilterscanbeused,seeReference[4].ForUTRANcellmeasurements,astraightaveragefiltercanonlybeusedwithafixedsetofparameter.
ThekeyparametersthatcontrolhandoversfromGSMtoUMTSareQSCandMRSL.ThefirstparametercontrolswhentheMulti-RATMSshouldmeasureonUMTS-frequencies,thesecondistheUTRANqualitycriterionwhichisvalidatedinBSS.
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AllUTRANcellstobeaddedtothecandidatelistmustfulfillthequalitycriterion:
CPICHEc/No>=MRSL (5)
wherethethresholdparameterMRSLissetintheBSC.
Othercriteriathatmustbefulfilledarerelatedtoeitherloadorurgency.AUTRANcellwillbeahandovercandidateonlyifanyorbothoftheurgencyorloadcriteriaarefulfilledinadditiontothequalitycriterion(5).Theurgencycriteriamaybeduetolargetimingadvance,baddownlinkqualityorbaduplinkquality.TheurgencycriteriaaredescribedinmoredetailinReference[4].Theloadcriterionisdescribedbelow.
PercentageofidleTCHintheservingcell
(always),ortovalues8-14ifthecellsareco-sited.ThisisbecausenoGSMsignallevelcriterionisneeded.
Example2:ItisonlywantedtoextendUMTScoveragewithGSM.ISHOLEVshouldbethansetto99inordertoprioritizeUMTSallthetime.BothQSCandQSIshouldbesetto7,or8-14ifthecellsareco-sited. FDDQOFFcanbe-infsinceallMSsaretobethrownbacktoUMTSinidlemodeaswell.
IftheGSMistobeextendedwiththeUMTScoverage,QSChastobeusedasathresholdbelowwhichUTRANmeasurementscanstart.InthatcaseISHOLEVshouldbesetto99.
3.3.4.3HandoverwithUsageofServiceIndicator
WiththefeatureHandoverwithUsageofServiceIndicator,thehandovercriteriaprovidedwithGSM-UMTSCellReselectionandHandoveraremodifieddependingonthevalueoftheServiceIndicator.TheServiceIndicatorisaBSSinternalparameterthatindicateswhethertheMSChasanypreferenceoninwhichsystem,GSMorWCDMA,aCSconnectionshallbeserved.ItwillhavethevalueasreceivedintheInformationElement|ServiceHandover|intheBBSMAPmessagesHandoverRequestandAssignmentRequestorthevalue|nopreference|iftheMSChasomittedtheInformationElement|ServiceHandover|.The|ServiceHandover|InformationElementmayhavethevalues|HandovertoUTRANshouldbeperformed|,|HandovertoUTRANshouldnotbeperformed|or|HandovertoUTRANshallnotbeperformed|.
IftheMSCindicatesthattheconnectionshallnotbehandedovertoUTRAN,BSSnevertriggersahandovertoUTRAN.IftheMSCindicatesthataconnectionshouldnotbehandedovertoUTRAN,BSSonlytriggersahandovertoUTRANincaseanyurgencycriterionisfulfilledintheGSMcell.IncasetheMSCindicatesthatahandovershouldbeperformed,BSStriggersahandovertoUTRANwhenthesignalqualityinthetargetcellisgoodenough,regardlessofthetrafficload.
TheServiceIndicatorisvalidperCSconnectionbutmaybechangedduringacall.Regardlessofusedhandovercriteria,allvalidneighbouringUTRANcellsaresortedinorderofdecreasingCPICHEc/No.AfinalcandidatelistiscreatedbypossiblyaddingUTRANcellstotheGSMcandidatecellsaccordingtothetablebelow.
Non-urgencyHO UrgencyHO
Noload Load Noload Load
Nopreference G UG GU UG
Should UG UG UG UG
shouldnot G G GU GU
shallnot G G G G
Table2CellorderinthefinalhandovercandidatelistwhenServiceIndicatorisused."Load"and"Noload"isi
Legend:G-onlyGSMcellsinthecandidatelist,UG-UTRANcellsareaddedonthetopofthecandidatelist,GU-UTRANcellsareaddedatthebottomofthecandidatelist.|Load|indicatesthattheloadcriterion(6)isfulfilled.|Urgency|indicatesthatanyoftheurgencycriteriaisfulfilled.
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Example1.IftheServiceIndicatorhasthevalue|HandovertoUTRANshallnotbeperformed|,theurgencycriterionforTimingAdvanceisfulfilled,andtheloadcriterion(6)isfulfillednohandovertoUTRANwilltakeplacesincethefinalhandovercandidatelistwillnotcontainanyUTRANcells.
Example2.IftheServiceIndicatorhasthevalue|HandovertoUTRANshouldbeperformed|andtheloadcriterion(6)isNOTfulfilled,handovertoUTRANwillbetriggeredifthereareanyUTRANcellsthatfulfillthequalitycriterion(5).
3.3.4.4SmoothGSMtoWCDMAUnloading
WiththefeatureSmoothGSMtoWCDMAUnloading,themaximumnumberofhandoverstoperformpersecondtoUTRANissetwiththeparameterMAXISHO,definedperGSMcell.WhenthenumberofhandovershavereachedthevaluesetbyMAXISHO,UTRANcellsarenotincludedinthecandidatelistproducedbyLocating.OnlythenumberofhandoversthataretriggeredbecauseofhightrafficloadintheGSMcell(loadcriterion(6)fulfilled),areexcludedandcounted.HandoversforconnectionswiththeServiceIndicatorwithavalueotherthan|Nopreference|,arenotcountednorexcluded.Neitherarehandoversduetourgencyexcludedorcounted.
IncominghandoversfromUTRANwithoutServiceIndicatorandwhichhascausevalues"DirectedRetry"or"Reduceloadinservingcell'willberejectedincaseofhightrafficloadintheGSMcell,thatiswhenloadcriterion(6)isfulfilled.
3.3.4.5CombinedHandoverTriggeringGSMtoWCDMA
WiththefeatureCombinedHandoverTriggeringGSMtoWCDMAitispossibletocontrolthemeasurementreportingofUTRANneighbouringcells.Theparameter FDDREPTHR2definesathresholdforthenonreportingradioentityoftheUTRANcells.NoUTRANcellswillbeincludedinthemeasurementreportsfromtheMSunlessthenonreportingUTRANradioentityisabovethedefinedthreshold.SinceUTRANcellsarereportedusingtheradioentityCPICHEc/No,theparameterFDDREPTHR2isrelatedtotheUTRANradioentityCPICHRSCP.
ThethresholdparameterFDDREPTHR2assuresasufficientdownlinksignalstrengthoftheUTRANcell,whichinturnincreasesthepossibilityforthemobiletoreachtheUTRANcellintheuplink.
ThethresholdparameterFDDREPTHR2isusedbyMSsbeinginconnectedmodeaswellasMSsbeinginNC2mode.
3.3.4.6QueuingofWCDMACallsinBSS
ThefeatureQueuingofWCDMACallsinBSSmakesitpossibletoprovideenhancednetworkaccessibilityinGSMtoprioritizedsubscriberscomingfromtheWCDMAnetworkviathedirectedretryprocedure.DirectedretryisusedduringcallsetupinWCDMAtosendthecalltoGSMduringcongestionintheWCDMAnetwork.PriorityandqueuinginformationissentfromthecorenetworktoBSSaspartofthedirectedretryprocedure.IncaseofcongestioninthetargetGSMcell,thehighprioritysubscriberisthenqueuedinBSS,togetherwithotherhighprioritysubscribers,accordingtotheirpriorityandtimeofarrivalinBSSuntiltherearefreeresourcesintheGSMcelloruntilatime-out(after10seconds)inBSS.
ThisfeatureworksasdescribedevenifthefeatureSmoothGSMtoWCDMAUnloadingisenabled.
Formoredetailsaboutthisfeature,seeReference[1]
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3.3.5 Location Area Update Procedure
Tomakeitpossiblefortheend-usertoreceiveacall,thenetworkmustknowwheretheMSislocated.TokeepthenetworkupdatedonthelocationoftheMS,thesystemisinformedbytheMS.ThisiscalledLocationUpdating(seeReference[2]).
AnoperatorcanconfigureGSMandUMTScellstobemembersofthesameregistrationarea(thatis,sameLAI)andtheMulti-RATMSdoesnotneedtoperformlocationupdatejustbecausethemobilehaschangedfromaUMTStoaGSMcell.AMulti-RATMSinitiatesnormallocationupdatingwhenitdetectsthatithasenteredanewlocationarea.WhentheMulti-RATMSislisteningtothesysteminformationtransmittedontheservingcell,itwillcomparethebroadcastLocationAreaIdentity(LAI)withtheonestoredintheMulti-RATMS.IfthebroadcastLAIdiffersfromtheonestored,alocationupdatingtypenormalwillbeinitiatedandthenewLAIwillbestoredintheMulti-RATMS.
IfaGSM-UMTShandoverhasoccurredtoanewLAduringacall,LocationUpdatingisperformedafterthecallhasfinished.
3.3.6 Routing Area Update Procedure
AnoperatorcanconfigureGSMandUMTScellstobemembersofthesameregistrationarea(thatis,sameRAI).DuringanintersystemcellreselectionfromGPRS/EGPRStoUMTSorUMTStoGPRS/EGPRS,differentproceduresarefolloweddependingonthemobilitymanagementstate(thatis,StandbyorReadystate)andtheNetworkOperationMode.
GenerallythesameproceduresareusedatintersystemcellreselectionbetweenGPRS/EGPRSandUMTSasforGPRS/EGPRScellreselection(seeReference[3]).AMulti-RATMSinitiatesaroutingareaupdatewhenitdetectsthatithasenteredanewroutingarea.
Inshort,thefollowingrelationsbetweenGPRS/EGPRSandUMTSmobilitymanagementstatesapplies:
UMTSPS-ConnectedStatecorrespondstoGPRS/EGPRSReadyState.
UMTSPS-IdleStatecorrespondstoGPRS/EGPRSStandbyState.
WhenaMulti-RATMSinUMTSPS-ConnectedStatechangestotheGSMradioaccess,orinGPRS/EGPRSReadyStatechangestotheUMTSradioaccess,theMulti-RATMSinitiates|RAupdate|procedureindependentofwhethertheRAhaschangedornot.
WhenaMulti-RATMSinUMTSPS-IdleStatechangestotheGSMradioaccess,orinGPRS/EGPRSStandbyStatechangestoUMTSradioaccess,theMulti-RATMSinitiates|RAupdate|procedureonlyiftheRAchanges.
IftheRAdoesnotchangewhenaMulti-RATMSinUMTSPS-IdleStatechangestoGPRS/EGPRSStandbyState(orviseversa),theMulti-RATMSshallinitiate|SelectiveRAupdate|procedure.ThismeansthattheMulti-RATMSonlyperformsaRAUpdatewhenuplinkdataorsignallingisrequiredorwhenitgetspaged(seeReference[9]).
TheGPRS/EGPRSMulti-RATMSperformsa|CombinedLA/RAUpdate|ifthenetworkoperatesinNetworkOperationModeIandiftheMulti-RATMSisbothPSandCSattached(Reference[9]).
3.4RelatedStatistics
3.4.1 Impact on Legacy Counters
None.
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3.4.2 Statistics for Performance Management
ThereareanumberofcountersperUTRANcellrelationintheobjectNUCELLRELCNT.
Countersrelatedtohandoverperformanceontheairinterface
Thenumberofhandovercommandssenttomobilestation,withtheneighbouringUTRANcellastargetcell(HOVERCNTUTRAN).
ThenumberofsuccessfulhandoverstotheneighbouringUTRANcell(HOVERSUCUTRAN).
ThenumberofhandoverattemptstotheneighbouringUTRANcellwhentheMSreturnedtotheoldchannel(HORTTOCHUTRAN).
ThenumberofhandovercommandssenttomobilestationduetourgencyintheGSMcell,withtheneighbouringUTRANcellastargetcell(URGHOVERUTRAN).
Thenumberofsuccessfulhandoverattempts,duetourgencyintheGSMcell,totheneighbouringUTRANcell(SUCURGHOUTRAN).
CountersrelatedtohandoverproceduresontheA-interface
ThenumberofhandoverrequiredsenttotheneighbouringUTRANcell(HOREQCNTUTRAN).
CountersrelatedtothefeatureHandoverwithUsageofServiceIndicator
NumberofhandoverattemptstoaneighbouringUTRANcellbecausetheServiceHandovervalueissetto|HandovertoUTRANshouldbeperformed|(HOATTSHOULDUTRAN).
CountersrelatedtothefeatureOptimizedthroughputatGSMtoWCDMACellChange
ThenumberofTBFspercellwherecellreselectiontoUTRANwasavoidedatleastoncewhileinNC2(IRATPREV).
CountersrelatedtothefeatureFastReturntoWCDMAafterCallRelease
ThenumberoftimeswhenthemessageCHANNELRELEASEissentwiththeIE"CellselectionindicatorafterreleaseofallTCHandSDCCH"
4EngineeringGuidelines
4.1Multi-RATMSCapabilities
ItisimportanttousetheEarlyClassmarksendingtoassurethatthesystemknowsabouttheMulti-RATcapabilities.WithEarlyclassmarksending(settingofparameterECSC=YES),theMulti-RATMSwillthensendClassmarkChangeassoonaspossibleaftercallsetup.Inthismessage,MSClassmark3isincluded,inwhichtheMulti-RATcapabilitiesofthemobilearedescribed.
4.2SystemInformation
TheUTRANcellstobemonitoredforintersystemcellreselectionaredefinedinthe3GneighbouringcelllistbroadcastonBCCH(SystemInformationType2quater).IfalsoaPBCCHexists,the3GneighbouringcelllistisbroadcastonPBCCH(PacketSystemInformationType3quater).The3Gneighbouringcelllistmaycontainupto64UTRANneighbours.
TheSI2quaterandPSI3quatermessagesareonlybroadcastifanyUTRANneighbouringcellsexistandtheexchangepropertyCOEXUMTSissettoON.
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SI2quatermaybesentoneitherBCCHnormalorBCCHextended(seeReference[12]).IfnotallinformationfitsintooneSI2quatermessage,theremaininginformationwillbesentinotherinstancesofthismessage.
WhenSI2quaterissent,AGBLKisrecommendedtobesetto1inthefollowingcases:
SI2bisandSI2teraresent.
GPRS/EGPRSisactiveandSI2bisissent.
GPRS/EGPRSisactiveandSI2terissent.
ThisisbecauseSystemInformation2quaterwillsharethesameresourcesasSystemInformation13and/orSystemInformation2teronBCCHnormalimplyinglongercyclefortheseSystemInformationtobebroadcast.Thiscouldimpactcellselection/reselectionperformance.WhenAGBLK=1,eitherSI2quaterorSystemInformation13areplacedonBCCHextendedintheabovecases.However,useofBCCHextendedimpliesreductionofthepagingcapacitysinceBCCHextendedsharestheresourcewithPCHandAGCH,seefurtherReference[2].
4.3CellReselectiontoUMTS
4.3.1 Camping Strategy for a Combined WCDMA/GSM Network
Thechoiceofsystemforidlemodecampingisimportant.TheMulti-RATMSshouldcamponthesystemwhereitisexpectedtosetupitsservicesandwhereitwillbepaged.InorderfortheMulti-RATMStobeabletoaccessUTRANspecificservicesitneedtocamponUTRAN.Therecommendedstrategyistherefore:
|camponUTRANwheneverthereisUTRANcoverage.
OutsideUTRANcoveragetheMulti-RATMSwillcamponGSM,togetaccesstostandardGSMservices.OnceaUTRANcellisselected/reselectedtheparametersettinginUTRANshouldtrytokeeptheUEinUTRANaslongasthequalityandreceivedsignalstrengthoftheUTRANcellisgoodenough.
TheGSMparametersettingsrecommendedinthisengineeringguidelineenablethecampingstrategydescribedabove.
4.3.2 Cell Selection
ItistheinitialprocessofthePLMNselectionthatdecideswhatPLMNwillbechoseninitially.ThisprocesswilldependontheMStype,aswellasbothoperatorcontrollableandusercontrollabledatastoredontheSIMcard,suchaspreferredPLMNandRAT(seeSection3.3.1andReference[10]).Thattypeofdatacannotbecontrolledbythecellreselectionparameters,assentbytheGSMnetworkinsysteminformationmessages.
4.3.3 Cell Reselection to UMTS
ItisimportanttocoordinatetheparametersinGSMandUTRANtoachievethewantedinterRATcellreselectionbehaviourandthusasmoothco-existence.ForextensiveinformationonthecellreselectionalgorithmfromUTRANtoGSMandcorrespondingparameters,parameterrangesanddefaultvalues,seeReference[15].
TherecommendedcellreselectionparametersettinginthefollowingsubchaptersarecoordinatedwiththecorrespondingparameterrecommendationsforUTRANtoGSMcellreselectionfoundinReference[15].
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4.3.3.1MeasurementsonUTRANNeighbouringCells
TheparameterQSIcontrolswhenthemulti-RATMSshallperformmeasurementsonUTRANneighbouringcells.
ToenablecellreselectiontoUTRANinareaswithgoodGSMcoverageitisnecessarytomeasureonUTRANalsowhenGSMcoverageisgood.TherecommendationisthatGSMcellsthathaveUTRANneighbourcellsshouldhavetheQSIvaluesettoalways.
4.3.3.2CellReselectionAlgorithm
WhenanMSisinNC0orNC1mode,thealgorithmforcellreselectionfromGSMtoWCDMAiscontrolledwiththeparametersFDDQMINandFDDQOFF.FDDQMINdefinestheminimumqualityoftheaWCDMAcellforcellreselection,measuredinCPICHEc/No.ThisparameterisusedtoassureasufficientqualityofthecandidateWCDMAcell.FDDQOFFsetsanoffset,positiveornegative,betweensignalqualityofGSMcellsandthedefinedWCDMAneighbours.Thecellreselectioncriteriaare:
CPICHEc/No>FDDQMIN (1)
and
CPICHRSCP>RLA(s+n)+FDDQOFF (2)
WhereRLA(s+n)istheaveragedreceivedsignallevel[dBm]forboththeservingGSMcellanditsstrongestGSMneighbours.
Foramulti-RATMSjustenteredGSMaping-pongbacktoUTRANisprohibitedbyatimer.Themulti-RATMSmustfulfilthetwocellreselectioncriteriaaboveforaperiodof5secondsafterthecellreselectiontoGSMandanadditionaloffsetof5dBwillbeaddedtoFDDQOFFduring15seconds.
ToachievethepreferredcampingbehaviourtheMulti-RATMSshouldcamponUTRANwhenthereisUTRANcoverage.ThismeansthatanegativevaluemustbesetforFDDQOFFifcellreselectionshallbepossiblewhenGSMcoverageisgood.AdrawbackwouldbethatcellreselectiontoaweakUTRANcellcouldbemadewhenGSMcoverageisgood.UsingahighersettingofFDDQMINpreventssucheffect.AsettingofFDDQMINasbelow,
FDDQMIN>qQualMin+sRatSearch+ahysteresis,
preventsthemulti-RATMSfrommakingcellreselectiontoaweakUTRANcell.ThisFDDQMINparametersettingwillalsomakesurethatthemulti-RATMSwillnotstarttomeasureontheGSMcellsimmediatelyincasetheMShasmadeacellreselectiontoUTRAN.qQualMinandsRatSearcharetheUTRANparametersthatdefinetheminimumqualitylevelthatisrequiredforaUTRANcellandatwhichpointthemeasurementonGSMcellsshallstart,seeReference[15].ItshallbenotedthattheqQualMinandsRatSearchparametersarerelatedtotheidlemode,Cell_FachstateandURA_PCHstateinWCDMA.AnothercaseisifapackettransferisongoingandifthepackettransferisgoingtocontinueusingadedicatedchannelontheWCDMAside.AsettingofFDDQMINasbelow,
FDDQMIN>usedFreqThresh2dEcno+ahysteresis
preventsthemulti-RATMSfromstartingmeasurementsonGSMcellsimmediatelyincasetheMShasmadeacellreselectiontoWCDMAandendeduponadedicatedchannelinWCDMA.
TherecommendedparametersettingofFDDQMINandFDDQOFFarethefollowing:
FDDQMIN=-10dB
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FDDQOFF=-inf
ThisparametersettingwillgiveacellreselectionalgorithmthatbasisthecellreselectiononthequalityoftheUTRANcellonly,thissincethecellreselectioncriteria2abovewillbefulfilledforallUTRANneighbours.
4.3.3.3CombinedCellReselectionTriggeringGSMtoWCDMA
Multi-RATmobilesthatsupportRSCPevaluationbeforetriggeringacellreselectiontoWCDMA,willevaluateUTRANcellsaccordingtocellreslectioncriteria(2),(3)and(4)below:
CPICHRSCP>RLA(s+n)+FDDQOFF (2)
CPICHEc/No>FDDQMIN - FDDQMINOFF (3)
and
CPICHRSCP>FDDRSCPMIN-min((P_MAX-21), 3dB) (4)
TherecommendedsettingsofFDDQOFFandFDDQMINareasdescribedinSection4.3.3.2.
TheparameterFDDQMINOFFhasapositivevalueandwilldecreasetheminimaldownlinkqualityCPICHEc/N0requiredforacellreselectiontotheUTRANcellandwiththesameargumentsasinSection4.3.3.2,thefollowingsettingisrecommendedforFDDQMINOFFincombinationwithFDDQMIN:
FDDQMIN - FDDQMINOFF>qQualMin+sRatSearch+ahysteresis
DuetotherecommendedsettingofqQualMInandsRATSearch,FDDQMINOFFcaneithertakethevale0or2dBandtherecommendedsettingofFDDQMINOFFis:
FDDQMINOFF=0dB.
TheabsoluteminimumCPICHRSCPvaluetoreselectaUTRANcellisgivenbytheselectionparameterqRxLevMininUTRAN.AsettingofFDDRSCPMINasbelow,
FDDRSCPMIN>qRxLevMin+sHcsRat+ahysteresis
preventsthemulti-RATmobiletotriggerareselectiontoaweakUTRANcell.ThisFDDRSCPMINparametersettingwillalsomakesurethatthemulti-RATMSwillnotstarttomeasureontheGSMcellsimmediatelyincasetheMShasmadeacellreselectiontoUTRAN.qRxLevMinandsHcsRataretheUTRANparametersthatdefinetheminimum|signalstrength|(CPICHRSCP)thatisrequiredforaUTRANcellandatwhichpointthemeasurementonGSMcellsshallstart,seeReference[15].
ItshallbenotedthattheqRxLevMinandSHcsRatparametesarerelatedtotheidlemodeandtheCellFachstateinWCDMA.AnothercaseisifapackettransferisongoingandifthepackettransferisgoingtocontinueusingadedicatedchannelontheWCDMAside.AsettingofFDDRSCPMINasbelow,
FDDRSCPMIN>usedFreqThresh2dRscp+ahysteresis
TherecommendedsettingofFDDRSCPminis:
FDDRSCPMIN=|102dBm
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Notethatforamobilewiththemaximumoutputpowerof21dBm,thecellreselectionwillbeperformedatthislevelbutforamobilewiththemaximumpoweroutputof24dBm,thecellreselectionwillbeperformedat|105dBm.
4.3.3.4OptimizedthroughputatGSMtoWCDMACellChange
SincethisfeatureisbasedonNC2,itisimportantthattheparametersforNC2areconfiguredproperlytothenetwork,seeReference[3].
4.3.4 Cell Reselection from UMTS to GSM
ForinformationoncellreselectionfromUTRANtoGSMandcorrespondingparameters,ranges,anddefaultvalues,seeReference[15].
4.4Intersystemcellselectionaftercallrelease
WhenthereisnoActiveUTRANMeasurementFrequencyListdefined,thereisariskthatthemobilewillbere-directedtoWCDMAeventhoughthereisnoWCDMAcoverage.ThemobilewillthenunsuccessfullysearchforWCDMAcellsandafterawhileselectaGSMcell.Insuchacase,thePagingoutagetimewillinsteadincrease.ThereforeitisrecommendedtousecommandRLRWEtoturnoffthefeatureinGSMcellswheretheUTRANcoverageispoorandwhennoActiveUTRANMeasurementFrequencyListhasbeenconfigured.
Iftheparameter QSIissetto15(=never),meaningthatmobileshouldnotmeasureonWCDMAcellswhileinidlemode,itisrecommendedtoturnoffthefeature(commandRLRWE)intheGSMcellinordertonotrequestthemobiletoselectaWCDMAcellaftercallrelease.
IfashorterpacketdatatransfertimehashigherprioritythanashorterPagingoutagetime,theparameterFASTRET3GNC2shouldbesetto1(=no-redirect)sothatthemobileisnotrequestedtoselectaWCDMAcellwhenthefeatureOptimizedthroughputatGSMtoWCDMACellChangeisactiveandaCSconnectionofaDTMcallisreleased.
4.5InterSystemHandover
4.5.1 General
ItisimportanttocoordinatetheparametersinGSMandUTRANtoachievethewantedintersystemhandoverbehaviourandthusasmoothco-existence.TherecommendedhandoverparametersettinginthefollowingsubchapteriscoordinatedwiththecorrespondingUTRANhandoverparametersettingfoundinReference[16].
4.5.2 Handover to UTRAN
Thefollowinghandoverparametersettingisrecommended:
1.SPRIO=Yes,motivation:securethatMulti-RATmobileshaveenoughtimefor3GmeasurementsalsoforthecasethentheMulti-RATmobileisbusywithmeasurementonGMSneighbours.
2.FDDMRR=1incasetheGSMcellhasGSMneighboursindifferentGSMbands(thatis,GSM900and1800band),motivation:minimizetheimpactonthemeasurementofGSMneighbours.
FDDMRR=2incasetheGSMcellhasneighbourswithinoneGSMband.Motivation:minimizeimpactonGSMmeasurementsbutallowmore3Gneighbourstobereportedcomparedtothecaseabove.
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3.QSC/ISHOLEV(alternative1,GSMusedtoextendUTRANcoverageandoff-loadGSMsystematcertaintrafficloadthreshold):
SetQSC=7(always)orQSC=8(above-78dBm)forUTRANcellco-sitedwithGSMcell.SetISHOLEV=wantedtrafficloadatwhichthehandoverUTRANshallstart.
4.QSC/ISHOLEV(alternative2,GSMusedtoextendUTRANcoverage):
SetQSC=7(always)orQSC=8(above-78dBm)forUTRANcellco-sitedwithGSMcell.SetISHOLEV=99.
5.QSC/ISHOLEV(alternative3,GSMtobeextendedwithUTRANcoverage):
SetQSC=1(below-94dBm)SetISHOLEV=99.
6. QSCI=1(always).
7.MRSL=30(-9dB)Motivation:thevalueoftheMRSLparametershallbesetsothatahandovertoUTRANisnotimmediatelyfollowedbya|ping-pong"handoverbacktoGSMandtoavoidstartingGSMmeasurementsdirectlywhenenteringUTRAN.ThisisachievediftheMRSLparameterhasthefollowingrelationtotheUTRANparameterusedFreqThresh2dEcno:
MRSL>usedFreqThresh2dEcno+ahysteresis.
Thesettingto-9dBfulfillstherelationsaboveusingthedefaultsettingoftheUTRANparameterusedFreqThresh2dEcno.
TheUTRANparameterusedFreqThresh2decno definestheEc/NothresholdwhenstartingtomeasureonGSMcells.
UTRANmayalsostartmeasurementsifmeasuredCPICHRSCP,whichisameasureofthedownlinksignalstrength,isbelowUsedFreqThresh2dRscp.SinceitmayaccurthatthemeasuredsignalqualityCPICHECN0isgoodbutthesignalstrengthweak,therecommendedMRSLsettingabovemayhavetobeadjustedtoahighervaluetopreventping-ponghandovers.
Theevent3aisusedinUTRANtotriggertheexecutionofahandoverfromUTRANtoGSM,forfurtherinformationseeReference[16].Themeasurementevent3aisdefinedasfollows:theestimatedqualityofthecurrentlyusedUTRANfrequencyisbelowacertainthresholdandtheestimatedqualityoftheGSMsystemisaboveacertainthresholdinthesametimeinterval.
4.5.3 Combined Handover Triggering GSM to WCDMA
InadditiontotherecommendedparametersettinginSection4.5.2thefollowingparametersettingsarerecommended:
1.FDDREPTHR2=16(-100dBm).Motivation:thevalueoftheFDDREPTRH2parametershallbesetsothatahandovertoUTRANisnotimmediatelyfollowedbya|ping-pong|handoverbacktoGSMandtoavoidstartingGSMmeasurementsdirectlywhenenteringUTRAN.ThisisachievediftheFDDREPTHR2parameterhasthefollowingrelationtotheUTRANparameterusedFreqThresh2dRscp:
FDDREPTHR2>usedFreqThresh2dRscp+ahysteresis.
Therecommendedsettingto-100dBmfulfillstherelationsaboveusingthedefaultsettingoftheUTRANparameterusedFreqThresh2dRscp.
TheUTRANparameterusedFreqThresh2dRscpdefinestheCPICHRSCPthresholdwhenstartingtomeasureonGSMcells.
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4.5.4 Handover to GSM
ForfurtherinformationregardingthehandoveralgorithmfromUTRANtoGSM,seeReference[16].
4.5.5 Smooth GSM to WCDMA Unloading
Thefollowingparametersettingsarerecommended:
MAXISHO=2,Motivation:therateatwhichloadvariesinacellpersecondisnormallyrelatedtothecellsize.Assumingacellwith20channelsandameanholdingtimeof90seconds,callsareinaveragesetupwitharateof20calls/90s,thatis,lessthanonecallpersecond.Therefore,tokeeptheloadlevelclosetoISHOLEV,alimitationof2handoverspersecondshouldbesufficient.Notethataslongastherearemulti-RATMSsinthecell,theloadwillvaryaroundthevaluesetbyISHOLEV.
5Parameters
5.1General
ThefeatureGSM-UMTSCellReselectionandHandoverisactivatedperBSCwiththeexchangepropertyCOEXUMTS.InadditionthefeaturesCombinedCellReselectionTriggeringGSMtoWCDMAandCombinedHandoverTriggeringGSMtoWCDMAcanbeactivatedwiththisexchangeproperty.
ThefeatureHandoverwithUsageofServiceIndicatorisactivatedperBSCwiththeexchangepropertySBHOACTIVE.
ThefeatureSmoothGSMtoWCDMAUnloadingisactivatedperBSCwiththeexchangepropertyCOEXUMTSLSH.
UTRANFDDneighbouringcellsareidentifiedwithafrequencyandscramblingcodecombination.Inidlemode,themeasurementfrequency(MFDDARFCN)andscramblingcodeMSCRCODEfortheneighbouringUTRANcellsaredefinedwithintheparameterUMFI.ThisparameterisalsousedtodefineifdiversityisappliedornotforanUTRANcell.Upto64UTRANneighbouringcellsmaybedefinedperGSMcell.Inactivemode,withinthedefinitionofneighbouringcellrelations,severalparametersaredefiningoneneighbouringUTRANcell:RadioFrequencyChannelNumber(FDDARFCN),ScramblingCode(SCRCODE),CellIdentity(UTRANID)andtheMinimumReportedSignalLevelforCPICHEc/No(MRSL).UTRANIDconsistsoftheRNCIdentity(RNCID),CellIdentitywithintheRNC(CI),MCC,MNCandLAC.
ThefeatureNC2isactivatedpercellusingthecommandRLNMI.TheNC2profileisselectedviatheparameterNCPROF.
5.2MainControllingParameters
5.2.1 Feature Controlling Parameters
COEXUMTS
isusedtoenablethefeaturesGSM-UMTSCellReselectionandHandover,CombinedCellReselectionTriggeringandCombinedHandoverTriggeringGSMtoWCDMA.TheparameterisaBSCexchangeproperty.
0OFF;GSM-UMTSCellReselectionandHandoverandCombinedCellReselectionTriggeringGSMtoWCDMAarenotactivated.
1ON;GSM-UMTSCellReselectionandHandoverisactivated
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2ONADDINFO;GSM-UMTSCellReselectionandHandoverandCombinedCellReselectionTriggeringGSMtoWCDMAareactivated
3ONADDINFO;GSM-UMTSCellReselectionandHandoverandCombinedHandoverTriggeringGSMtoWCDMAareactivated
4ONADDINFO;GSM-UMTSCellReselectionandHandover,CombinedCellReselectionTriggeringGSMtoWCDMAandCombinedHandoverTriggeringGSMtoWCDMAareactivated
COEXUMTSLSH
isusedtodetermineifrejectionofincominghandoversfromUTRANandlimitationofthenumberofoutgoinghandoverstoUTRANduetoloadinGSMisallowed(=ON)ornot(=OFF)intheBSC.TheparameterisaBSCexchangeproperty.
0OFF
1ON
FASTRET3G
showstheactivationstatusofthefeatureFastReturntoWCDMAafterCallRelease(activated/deactivated/printedwiththecommandsRLRWI/RLRWE/RLRWP).
Active
Inactive
FASTRET3GNC2
controlswhethertoredirectDTMcallsaftercallreleasewhenthefeatureOptimizedthroughputatGSMtoWCDMACellChangeisactive.TheparameterisaBSCexchangeproperty.
0re-direct
1donotre-direct
NCPROF
indicateswhichNC2profileistobeactivatedinacellwhenanMSisinNC2mode.Thedefaultvalueis1whichactivatesthefeatureOptimizedthroughputatGSMtoWCDMACellChange.Thevaluerangeis1|255,where2|255areundefined.
SBHOACTIVE
isusedtodetermineifhandoverwithusageofServiceIndicatorisallowed(=ON)ornot(=OFF)intheBSC.TheparameterisaBSCexchangeproperty.
0OFF
1ON
5.2.2 Parameters for Inter System Cell Reselection to UMTS
FDDQMINdefinestheminimumthresholdforthe|quality|measureEc/NoforcellreselectiontoUTRAN.ThisparameterisdefinedperGSMcellandappliesforallitsUTRANneighbours.
FDDQMINOFFdefinesanoffsettothethresholdFDDQMIN.ThisparameterisdefinedperGSMcellandappliesforallitsUTRANneighbours.
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FDDQOFFdefinestheminimumthresholdforthe|quality|measureEc/NoforcellreselectiontoUTRAN.ThisparameterisdefinedperGSMcellandappliesforallitsUTRANneighbours.
FDDRSCPMINdefinestheminimumthresholdforthe|signalstrength|measureCPICHRSCPforcellreselectiontoUTRAN.ThisparameterisdefinedperGSMcellandappliesforallitsUTRANneighbours.
QSIdefinesifthemonitoringofUMTScellswillbeperformedifthesignallevelisbelow(0-6)orabovethethreshold(8-14),always(7)ornever(15).ThisparameterisdefinedperGSMcell.
UMFI
(MFDDARFCN-MSCRCODE-DIVERSITY)definesthefrequency,scramblingcodeanddiversityinformationforaUTRANneighbouringcell.
MFDDARFCNindicatestheabsoluteRFchannelnumberoftheneighbouringUTRANcelltobemeasuredonbyMulti-RATMSs.SeveralfrequencybandsexistandtheabsoluteRFchannelnumberrepresentsthecenterfrequencywithinthefrequencyband.AllowedfrequencybandsandabsoluteRFchannelnumbersaredescribedindetailinReference[13].
MSCRCODEisthescramblingcodefortheneighbouringcell.Thescramblingcodehas512values.
DIVERSITYindicatesifdiversityisappliedfortheUTRANcell,ornot.
ThisparameterisdefinedperGSMcell.
5.2.3 Parameters for Inter System Handover to UMTS
COEXUMTSTINTisusedtocontrolthetimeintervalbetweentrafficloadchecking.ThisparameterisaBSCexchangeproperty.
FDDARFCN
indicatestheabsoluteRFchannelnumberoftheneighbouringUTRANcellinGSMactivemode.SeveralfrequencybandsexistandtheabsoluteRFchannelnumberrepresentsthecenterfrequencywithinthefrequencyband.AllowedfrequencybandsandabsoluteRFchannelnumbersaredescribedindetailinReference[13].ThisparameterisdefinedperUTRANcell.
FDDMRRdefinesthenumberofUTRANcellsthatthemobileshouldincludeinmeasurementreports.ForadetaileddescriptionseeSection3.3.4.2.ThisparameterisdefinedperGSMcell.
ISHOLEVdefinesthetrafficloadthresholdoftheservingGSMcellthatneedstobeexceededinordertoevaluateUMTSmeasurementsforhandovers.ThisparameterisdefinedperGSMcell.
MAXISHO
definesthemaximumnumberofallowedhandoverstotriggertoUTRANpersecond.OnlyhandoversthataretriggeredbecauseoftrafficloadintheGSMcellarecountedorlimited.ThisparameterisdefinedperGSMcell.
MRSLdefinesaminimumthresholdforthe"quality"measureEc/NoforhandoverstoUTRAN.ThisparameterisdefinedperUTRANcell.
FDDREPTHR2
definesathresholdforthenonreported|signalstrength|measureCPICHRSCPofUTRANcells.TheMSincludesaUTRANcellinthemeasurementreportsonlyifthenonreportingthresholdisexceeded.ItshallbenotedthatthereportingentityinthemeasurementreportsisCPICEc/No.ThisparameterisdefinedperGSMcell.
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SCRCODEisthescramblingcodefortheneighbouringUTRANcellinactivemode.Thescramblingcodehas512combinations.ThisparameterisdefinedperUTRANcell.
SPRIO indicatesif3GcellsmaybesearchedwhenBSICdecodingisrequired.ThisparameterisdefinedperGSMcell.
UTRANIDUTRANIDpresenttheIdentityoftheneighbouringUTRANcellinactivemode.ItconsistsoftheRNCIdentity(RNCID),CellIdentitywithintheRNC(CI),MCC,MNCandLAC.ThisparameterisdefinedperUTRANcell.
QSCdefinesifthemonitoringofUMTScellswillbeperformedifthesignallevelisbelow(0-6)orabovethethreshold(8-14).always(7)ornever(15).ThisparameterisdefinedperGSMcell.
QSCI
definesthecontrolofUTRANmeasurementafterenteringactivemode,beforereadingthefirstQSC.InthatperiodUTRANmeasurementscanalwaysbeperformed(=1)oraccordingtoQSIvalue(=0).ThisparameterisdefinedperGSMcell.
GPRSPRIO
GPRSPRIOisaBSCcellparameterthatcontrolswhetheron-demandPDCHsshallberegardedasidleorbusywhentrafficload(percentageofidlechannels)iscalculatedinthecell(seeparameterdescriptioninReference[7]).
5.3ValueRangesandDefaultsValues
Parameter name Default value
Recommended value
Value range Unit
COEXUMTS 0(OFF) - 0(OFF),1(ON),2(ONADDINFO),3(ONADDINFO),4(ONADDINFO)
COEXUMTSLSH 0(OFF) - 0(OFF),1(ON)
FASTRET3GNC2 0(re-direct)
0 0(re-direct)
1(donotre-direct)
SBHOACTIVE 0(OFF) - 0(OFF),1(ON)
NCPROF 1 1 1(OptimizedthroughputatGSMtoWCDMACellChange)
Values2|255areundefined.
-
Table3FeatureControllingParameters
Parameter name Default value
Recommended value
Value range Unit
Table4ParametersforInterSystemCellReselectiontoUMTS
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UMFI(MFDDARFCN-MSCRCODE-DIVERSITY)
- - MFDDARFCN:0to16383MSCRCODE:0to511
DIVERSITY:DIV,NODIV
FDDQMIN 0(-20dB) 5(-10dB) 0to7(-20dB,-6dB,-18dB,-8dB,-16dB,-10dB,-14dB,-
12dB)
dB
FDDQMINOFF 0(0dB) 0(0dB) 0to7(0to14dBinstepsof2dB)
dB
FDDQOFF 8(0dB) 0(-inf) 0to15(-inf,-28dBto+28dBinstepsof4dB)
dB
FDDRSCPMIN 6(-102dBm)
6(-102dBm) 0to15(-114dBmto|84dBminstepsof2dBm)
dBm
QSI 15(never) 7(always) 0to6(below-98dBmto-74dBminstepsof4dBm)7(always)8to14(above-
78dBmto-54dBminstepsof4dBm)15(never)
dBm
Parameter name Default value
Recommended value
Value range Unit
COEXUMTSTINT 1000 1000 100to1000 ms
FDDARCN - - 0to16383
SCRCODE - - 0to511
UTRANID(RNCID-CI-MCC-MNC-LAC)
- - RNCID:0to4095CI:0to65535MCCMNCLAC
MRSL - 30(-9dB) 0to49
(0:MRSL
GSM Candidate List Alistofcandidatesforhandover,asaresultoftheGSMpartofthelocatingalgorithm.ByaddingtheUMTSneighboursonthetop,afinallistiscreated.
CPICH RSCP AMulti-RATMSmeasuresReceivedSignalCodePoweronneighbouringUTRANcellsinordertoevaluateintersystemcellreselectioncandidates.RSCPistheaveragepowerofthereceivedsignalafterdespreadingandcombining.
Home PLMN ThePLMNwheretheMCCandMNCofthePLMNidentitymatchtheMCCandMNCoftheIMSI.
Idle Mode Inthismode,themobilestationisnotallocatedanydedicatedchannel.ItlistenstotheCCCHandtheBCCH.
Inter System Cell Reselection Cellreselectionbetweennetworksusingdifferentradioaccess,forexampleGSMandUMTS.
Multi-RAT MS UserequipmentthatcanobtainservicefromGSMandoneormoredifferentRATssuchasUMTS.
On-demand PDCH APDCHwhichissetupandreleaseddynamicallydependingontheneedforpacketdatatrafficinthecell.ANon-demandPDCHmaybePDCHpre-empted.
Paging outage time ThePagingOutageTimeisreferredtoasthetimewhenanMScannotbereachedbyapagingmessage
PSI 3quater SysteminformationmessageonPBCCHusedbyMulti-RATMSsinGPRS/EGPRSReadyandStandbystates.
Packet Idle Mode Inthismode(onlyapplicableformobilestationssupportingGPRS/EGPRS),mobilestationisnotallocatedanyradioresourceonapacketdataphysicalchannel.ItlistenstothePBCCHandPCCCHor,ifthenetworkdoesnotprovidethose,totheBCCHandtheCCCH.
Packet Transfer Mode Inthismode(onlyapplicableformobilestationssupportingGPRS/EGPRS),themobilestationisallocatedradioresourceononeormorepacketdataphysicalchannels.
PDCH AfullrateTCHordualrateTCHintheCSdomainthatisallocatedbythePSdomaintocarryGPRS/EGPRStraffic.
Registered PLMN ThePLMNtowhichLocationRegistrationhasbeenperformed.
Service Indicator TheServiceIndicatorisaBSSinternalparameterthatindicateswhethertheMSChasanypreferenceoninwhich
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system,GSMorWCDMA,aCSconnectionshallbeserved.ItwillhavethevalueasreceivedintheInformationElement|ServiceHandover|intheBBSMAPmessagesHandoverRequestandAssignmentRequestorthevalue|nopreference|iftheMSChasomittedtheInformationElement|ServiceHandover|.The|ServiceHandover|InformationElementmayhavethevalues|HandovertoUTRANshouldbeperformed|,|HandovertoUTRANshouldnotbeperformed|or|HandovertoUTRANshallnotbeperformed|
SI 2quater SystemInformationmessageonBCCHusedbyMulti-RATMSsinidlemodeandGPRS/EGPRSReadyandStandbymode.
Urgency Handover UrgencyhandoverisahandovertriggeredbecauseanurgencycriteriaisfulfilledintheservingGSMcell.Theurgencycriteriamaybeduetolargetimingadvance,baddownlinkqualityorbaduplinkquality.
UTRAN FDD UTRANhastwomodes,FDDandTDD,foroperatingwithpairedorunpairedbandsrespectively.FDDisaduplexmethodwherebyuplinkanddownlinktransmissionsusetwoseparatedradiofrequencies.
Glossary
BA
BCCHAllocation
BCCH
BroadcastControlChannel
BSC
BaseStationController
CPICH
CommonPilotChannel
CS
CircuitSwitched
EGPRS
EnhancedGPRS
FDD
FrequencyDivisionDuplex
GPRS
GeneralPacketRadioService
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GSM
GlobalSystemforMobilecommunication
IMSI
InternationalMobileSubscriberIdentity
LA
LocationArea
LAC
LocationAreaCode
LAI
LocationAreaIdentity
MCC
MobileCountryCode
MNC
MobileNetworkCode
MS
MobileStation
NCC
NetworkColorCode
PBCCH
PacketBroadcastControlChannel
PDCH
PacketDataChannel
PLMN
PublicLandMobileNetwork
PS
PacketSwitched
RA
RoutingArea
RAT
RadioAccessTechnology
RLA_C
ReceivedLevelAverage(circuitswitched)
RLA_P
ReceivedLevelAverage(packetswitched)
RNC
RadioNetworkController
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RSCP
ReceivedSignalCodePower
SACCH
SlowAssociatedControlChannel
SIM
SubscriberIdentityModule
UMTS
UniversalMobileTelecommunicationsSystem
UTRAN
UMTSRadioAccessNetwork
WCDMA
WidebandCodeDivisionMultipleAccess
ReferenceList
EricssonDocuments[1]UserDescription,EnhancedMulti-LevelPrecedenceandPre-emptionService,(UserDescription)
[2]UserDescription,IdleModeBehaviour,(UserDescription)
[3]UserDescription,GPRS/EGPRSCellReselection,(UserDescription)
[4]UserDescription,Locating,(UserDescription)
[5]UserDescription,DoubleBALists,(UserDescription)
[6]UserDescription,MultibandOperation,(UserDescription)
[7]UserDescription,ChannelAdministration,(UserDescription)
Standards[8]3GPPTS45.008,(GSMSpecification)
[9]3GPPTS23.060,(GSMSpecification)
[10]3GPPTS23.122,(GSMSpecification)
[11]3GPPTS25.304,(GSMSpecification)
[12]3GPPTS45.002,(GSMSpecification)
[13]3GPPTS25.101,(GSMSpecification)
[14]3GPPTS44.060,(GSMSpecification)
WCDMAUserDescriptions[15]UserDescription,IdleModeBehaviourandConnectedModeBehaviourincell_FACHstate,(UserDescription)
[16]UserDescription,WCDMARANHandover,(UserDescription)
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