SIST EN 300 948 V8.0.1:2003
(Main)Digital cellular telecommunications system (Phase 2+) (GSM); Group Call Control (GCC) protocol (GSM 04.68 version 8.0.1 Release 1999)
- Abstract
Upgrade to Release 1999
- Status
- Published
- Publication Date
- 30-Nov-2003
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-Dec-2003
- Due Date
- 01-Dec-2003
- Completion Date
- 01-Dec-2003
SIST EN 300 948 V8.0.1:2003 is the Slovenian standard that adopts EN 300 948 Version 8.0.1. It specifies the Group Call Control (GCC) protocol used by the Voice Group Call Service (VGCS) on the GSM radio interface, for communication between a Mobile Station (MS) and the network.
What does SIST EN 300 948 V8.0.1:2003 specify?
SIST EN 300 948 V8.0.1:2003 specifies the GCC protocol for GSM Phase 2+ Release 1999 and says that support of the protocol is optional in both the MS and the network. It focuses on one GCC entity in the network and one or more GCC entities in MSs, and it leaves dispatcher protocol specification out of scope.
The document is organized into:
- Scope, references, definitions and abbreviations
- Applicability and main concepts
- Elementary procedures for Group Call Control
- Handling of unknown, unforeseen and erroneous protocol data
- Message functional definitions and contents
- Content coding of information elements
- Annex A with change request history
What are the key requirements of SIST EN 300 948 V8.0.1:2003?
SIST EN 300 948 V8.0.1:2003 defines the GCC behavior as a set of finite-state procedures, message exchanges and timer-driven reactions. In practice, implementers have to match the state model, send the right messages, and clear or retain call context exactly as the protocol states.
State machines and parameters
The MS side uses states such as NULL, MMCONNECTIONPENDING, GROUPCALLINITIATED, GROUPCALLACTIVE, GROUPCALLPRESENT, GROUPCALLCONNECTIONREQUESTED and TERMINATIONREQUESTED. The network side uses NULL, GROUPCALLINITIATED, GROUPCALLACTIVE, GROUPCALLESTABLISHMENTPROCEEDING and TERMINATIONREQUESTED.
The MS also tracks parameters and configuration such as ORIG, COMM, D-ATT and U-ATT. These values determine whether the MS considers itself the originator, whether communication is enabled, and whether the user connection is attached in downlink and uplink.
Call establishment
A group call can be started by the network or by the MS. For mobile-originated setup, the MS uses either SETUP after explicit MM connection establishment or IMMEDIATESETUP with implicit MM connection establishment.
For mobile-terminated setup, the MS can receive a group call indication and move to GROUPCALLPRESENT, then join the call on higher-layer request. This matters because the MS must distinguish between being notified of a call and actually joining it.
Active call handling
In the active state, the MS changes sub-states according to the radio resource connection mode, including separate link, receive mode, send and receive mode, and no channel. The document ties these sub-states to the RR connection state, so implementers must coordinate GCC and RR behavior.
The network may also send SETPARAMETER to request changes in MS parameters, including COMM when the uplink is requested. This is the protocol mechanism for changing how the MS participates in the call.
Release, abort and termination
The standard defines TERMINATIONREQUEST, TERMINATION, and TERMINATIONREJECT. The MS uses TERMINATIONREQUEST to ask for termination of a call it originated, while the network uses TERMINATION to indicate that a call has been or will be terminated.
If termination is rejected or times out, the MS returns to NULL and clears the group call context. This prevents stale call state from being retained after a failed release attempt.
Error and exception handling
Clause 7 defines how the MS handles short messages, unknown transaction identifiers, unknown message types, missing or invalid mandatory information, and semantically incorrect messages. The procedures are ordered by precedence, so receivers know whether to ignore a message or respond with a STATUS message and a cause value.
That behavior is important for interoperability because it gives a defined response to malformed or future-extended messages.
What terms does SIST EN 300 948 V8.0.1:2003 define?
- Group Call Control (GCC) - The Layer 3 protocol that controls group calls between the MS and the network.
- Voice Group Call Service (VGCS) - The service that uses GCC to support voice group calls on the GSM radio interface.
- Mobile Station (MS) - The mobile side of the GCC peer relationship.
- calling user - The GCC entity in the MS that initiates, or has initiated, a group call.
- group call channel - The combined uplink/downlink resource used for one group call in a cell.
- originating Mobile Station - The MS that initiates, or is treated as having initiated, the group call.
- clearing the context related to the group call establishment - Stopping running GCC timers and deleting the related GCC attributes.
Who uses SIST EN 300 948 V8.0.1:2003?
SIST EN 300 948 V8.0.1:2003 is used by GSM radio-interface engineers, MS implementers, network-side protocol developers, and system integrators working with VGCS. It is also relevant to test labs and quality teams that need to verify call setup, termination, status reporting and error handling.
What changed in SIST EN 300 948 V8.0.1:2003 from the previous edition?
Annex A lists the change-request history. The recorded changes include corrections to the GETSTATUS and SETSTATUS procedures, coding of the CallReference IE, the RejectCause in TERMINATIONREJECT, a message-name correction, and the upgrade for Release 1999.
Which standards are used with SIST EN 300 948 V8.0.1:2003?
The document relies on several GSM references:
- GSM01.04 - abbreviations and acronyms used in GSM
- GSM02.68 - Voice Group Call Service (VGCS) Stage 1
- GSM03.03 - numbering, addressing and identification
- GSM03.67 - enhanced Multi-Level Precedence and Pre-emption service
- GSM03.68 - VGCS Stage 2
- GSM04.06 - MS-BSS data link layer
- GSM04.07 - general aspects of mobile radio interface signalling layer 3
- GSM04.08 - mobile radio interface layer 3 specification
What does the SIST EN 300 948 V8.0.1:2003 document contain?
The document contains state diagrams and state tables for MS and network behavior, timer definitions, message definitions, and coding rules for information elements. It gives the functional content of messages such as CONNECT, GETSTATUS, IMMEDIATESETUP, SETPARAMETER, SETUP, STATUS, TERMINATION, TERMINATIONREJECT and TERMINATIONREQUEST.
It also defines how to code CallReference, Callstate, Cause, Originatorindication and Stateattributes. That makes the document useful not only for implementation, but also for interoperability testing and protocol conformance checks.
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Frequently Asked Questions
SIST EN 300 948 V8.0.1:2003 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Digital cellular telecommunications system (Phase 2+) (GSM); Group Call Control (GCC) protocol (GSM 04.68 version 8.0.1 Release 1999)". This standard covers: Upgrade to Release 1999
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SIST EN 300 948 V8.0.1:2003 is classified under the following ICS (International Classification for Standards) categories: 33.070.50 - Global System for Mobile Communication (GSM). The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 300 948 V8.0.1:2003 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.NUPLOMHQMDDigital cellular telecommunications system (Phase 2+) (GSM); Group Call Control (GCC) protocol (GSM 04.68 version 8.0.1 Release 1999)33.070.50Globalni sistem za mobilno telekomunikacijo (GSM)Global System for Mobile Communication (GSM)ICS:Ta slovenski standard je istoveten z:EN 300 948 Version 8.0.1SIST EN 300 948 V8.0.1:2003en01-december-2003SIST EN 300 948 V8.0.1:2003SLOVENSKI
STANDARD
ETSIEN300948V8.0.1(2000-08)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2+);GroupCallControl(GCC)protocol(GSM04.68version8.0.1Release1999)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)2(GSM04.68version8.0.1Release1999)ReferenceREN/SMG-030468Q8KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)ETSI650RoutedesLuciolesF-06921SophiaAntipolisCedex-FRANCETel.:+33492944200Fax:+33493654716SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/88ImportantnoticeIndividualcopiesofthepresentdocumentcanbedownloadedfrom:http://www.etsi.orgThepresentdocumentmaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.Usersofthepresentdocumentshouldbeawarethatthedocumentmaybesubjecttorevisionorchangeofstatus.InformationonthecurrentstatusofthisandotherETSIdocumentsisavailableathttp://www.etsi.org/tb/status/Ifyoufinderrorsinthepresentdocument,sendyourcommentto:editor@etsi.frCopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)3(GSM04.68version8.0.1Release1999)ContentsIntellectualPropertyRights.5Foreword.51Scope.62References.63Definitionsandabbreviations.63.1Definitions.63.2Abbreviations.74Applicability.75Mainconcepts.76ElementaryproceduresforGroupCallControl.86.1Overview.86.1.1General.86.1.2Groupcallcontrolstates.106.1.2.1GroupcallcontrolstatesattheMSsideoftheinterface.106.1.2.1.1AttributesandparametersofGCCintheMS.106.1.2.1.2NULL(U0).106.1.2.1.3MMCONNECTIONPENDING(U0.p).106.1.2.1.4GROUPCALLINITIATED(U1).106.1.2.1.5GROUPCALLACTIVE(U2).116.1.2.1.6GROUPCALLPRESENT(U3).116.1.2.1.7GROUPCALLCONNECTIONREQUESTED(U4).116.1.2.1.8TERMINATIONREQUESTED(U5).116.1.2.1.9Sub-statesoftheGroupcallactivestate.116.1.2.1.10GCCTimersintheMS.126.1.2.1.11Consistencyofparametersandstates.126.1.2.2Groupcallcontrolstatesatthenetworksideoftheinterface.136.1.2.2.1NULL(StateN0).136.1.2.2.2GROUPCALLINITIATED(N1).136.1.2.2.3GROUPCALLACTIVE(N2).136.1.2.2.4GROUPCALLESTABLISHMENTPROCEEDING(N3).136.1.2.2.5TERMINATIONREQUESTED(N4).136.2Proceduresforestablishmentofagroupcall.136.2.1Activationofagroupcallbythenetwork.136.2.2Mobileoriginatedestablishment.136.2.2.1Terminationduringmobileoriginatedestablishment.146.2.2.2Abnormalcases.146.2.3MobileterminatinggroupcallestablishmentintheMS.156.3Proceduresduringtheactivestateofagroupcall.156.3.1Mobilestationproceduresintheactivestate.156.3.1.1Sub-statetransitionsintheMS.156.3.2Networkproceduresintheactivestate.166.4Proceduresforrelease,abortion,andterminationofagroupcall.166.4.1Terminationprocedure.166.4.2Abortandreleaseprocedures.166.5Miscellaneousprocedures.176.5.1Statusprocedures.176.5.1.1Getstatusprocedure.176.5.1.2Setparameterprocedure.177Handlingofunknown,unforeseen,anderroneousprotocoldata.177.1General.177.2Messagetooshort.187.3Unknownorunforeseentransactionidentifier.18SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)4(GSM04.68version8.0.1Release1999)7.4Unknownorunforeseenmessagetype.187.5Non-semanticalmandatoryinformationelementerrors.187.6Unknownandunforeseeninformationelementsinthenon-imperativemessagepart.197.6.1Informationelementsunknowninthemessage.197.6.2Outofsequenceinformationelements.197.6.3RepeatedInformationelements.197.7Non-imperativemessageparterrors.197.7.1SyntacticallyincorrectoptionalInformationelements.197.8Messageswithsemanticallyincorrectcontents.198Messagefunctionaldefinitionsandcontents.208.1CONNECT.218.2GETSTATUS.218.2.1mobileidentity.218.3IMMEDIATESETUP.228.3.1Mobileidentity.228.4SETPARAMETER.228.5SETUP.238.6STATUS.238.6.1Callstate.238.6.2Stateattributes.238.7TERMINATION.248.8TERMINATIONREJECT.248.9TERMINATIONREQUEST.259Contentsofinformationelementsvalueparts.259.1ProtocolDiscriminator.259.2Transactionidentifier.259.3MessageType.259.4Otherinformationelements.269.4.1CallReference.269.4.2Callstate.279.4.3Cause.279.4.4Originatorindication.289.4.5Notused.299.4.6SpareHalfOctet.299.4.7Stateattributes.29AnnexA(informative):ChangeRequestHistory.30History.31SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)5(GSM04.68version8.0.1Release1999)IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinETSISR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinETSISR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbyETSITechnicalCommitteeSpecialMobileGroup(SMG).ThepresentdocumentspecifiestheGroupCallControl(GCC)protocolusedbytheVoiceGroupCallService(VGCS)ontheradiointerfacewithinthedigitalcellulartelecommunicationssystem(Phase2+).ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinTC-SMGandmaychangefollowingformalTC-SMGapproval.ShouldTC-SMGmodifythecontentsofthepresentdocument,itwillberesubmittedforOAPbyETSIwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version8.x.y8IndicatesGSMPhase2+Release1999;xtheseconddigitisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.;ythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification.NationaltranspositiondatesDateofadoptionofthisEN:14July2000DateoflatestannouncementofthisEN(doa):31October2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):30April2001DateofwithdrawalofanyconflictingNationalStandard(dow):30April2001SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)6(GSM04.68version8.0.1Release1999)1ScopeThepresentdocumentspecifiestheGroupCallControl(GCC)protocolusedbytheVoiceGroupCallService(VGCS)ontheradiointerface.2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.• Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.• Foraspecificreference,subsequentrevisionsdonotapply.• Foranon-specificreference,thelatestversionapplies.• Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.• ForthisRelease1999document,referencestoGSMdocumentsareforRelease1999versions(version8.x.y).[1]GSM01.04(ETR350):"Digitalcellulartelecommunicationsystem(Phase2+);Abbreviationsandacronyms".[2]GSM02.68(ETS300925):"Digitalcellulartelecommunicationsystem(Phase2+);"VoiceGroupCallService(VGCS)-Stage1".[3]GSM03.03(ETS300927):"Digitalcellulartelecommunicationsystem(Phase2+);Numbering,addressingandidentification".[4]GSM03.67(ETS300932):"Digitalcellulartelecommunicationsystem(Phase2+);"enhancedMulti-LevelPrecedenceandPre-emptionservice(eMLPP)-Stage2".[5]GSM03.68(ETS300933):"Digitalcellulartelecommunicationsystem(Phase2+);VoiceGroupCallService(VGCS)-Stage2".[6]GSM04.06(ETS300938):"Digitalcellulartelecommunicationsystem;MobileStation-BaseStationSystem(MS-BSS)interfaceDataLink(DL)layerspecification".[7]GSM04.07(ETS300939):"Digitalcellulartelecommunicationsystem(Phase2+);Mobileradiointerfacesignallinglayer3Generalaspects".[8]GSM04.08(ETS300940):"Digitalcellulartelecommunicationsystem(Phase2+);Mobileradiointerfacelayer3specification".3Definitionsandabbreviations3.1DefinitionsDefinitionsusedinthepresentdocumentarealsodefinedinGSM02.68.Forthepurposesofthepresentdocumentthefollowingtermsanddefinitionsapply:attachmentoftheuserconnection:seeGSM04.08,subclause5.2.callinguser:GCCentityintheMobileStation(MS)initiatingorhavinginitiatedagroupcall.SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)7(GSM04.68version8.0.1Release1999)clearingthecontextrelatedtothegroupcallestablishment:allrunningGCCtimersintherelevantGCCentityarestopped,allattributesintherelevantGCCentityaredeleted.downlink:networktomobilestationdirection.groupcall:isusedinthesamesenseas"voicegroupcall".groupcallchannel:combineduplink/downlinktobeallocatedineachcellofthegroupcallareaforaparticulargroupcall.Theuplinkcanbeusedbythepresentlytalkingservicesubscriberonly.AllMSsofthelisteningservicesubscribersinonecellshalllistentothecommondownlink.groupreceivemode:seeGSM04.08.originatingmobilestation:mobilestationinitiatingorhavinginitiatedthegroupcall.(Notethat,incertainsituations,aMSassumestobetheoriginatingMSofagroupcallwithoutactuallybeingtheoriginatingMSofthatgroupcall.NotethattheremaybeoneornoneoriginatingMSforagivengroupcall).uplink:mobilestationtonetworkdirection.3.2AbbreviationsAbbreviationsusedinthepresentdocumentarealsolistedinGSM01.04.Forthepurposesofthepresentdocument,thefollowingabbreviationsapply:GCCGroupCallControl4ApplicabilitySupportofthegroupcallprotocolisoptionalintheMSandinthenetwork.5MainconceptsThepresentdocumentdescribesthegroupcallcontrol(GCC)protocol,whichisoneoftheprotocolsoftheConnectionManagement(CM)sublayer(seeGSM04.07).ThereisingeneralmorethanoneMSengagedinagroupcall.Consequently,thereisingeneralmorethanoneMSwithaGCCentityengagedinthesamegroupcall,andthereisoneGCCentityinthenetworkengagedinthatgroupcall.UnderwhichconditionsaGCCmessageispassedfromlower(sub-)layerstotheGCCentityisdefinedinthespecificationsofthesub-layers.TheMSshallignoreGCCmessagesthatitreceiveswhichweresentinunacknowledgedmodeandwhichexplicitlyspecifyasdestinationamobileidentitywhichisnotamobileidentityoftheMS.HigherlayersandtheMMsub-layerdecidewhentoacceptparallelGCCtransactionsandwhen/whethertoacceptGCCtransactionsinparalleltootherCMtransactions.Thegroupcallmaybeinitiatedbyamobileuserorbyadispatcher.Specificationofaprotocolfordispatchersisoutofthescopeofthepresentdocument.Hence,inthescopeofthepresentdocument,thereare:-oneGCCentityinthenetwork;and-oneormorethanoneGCCentitiesindifferentMSs;engagedinagroupcall,andoneorenoneoftheMSsistheoriginatorofthegroupcall(calledtheoriginatingMSinthepresentdocument).Notethat,incertainsituations,aMSassumestobetheoriginatorofagroupcallwithoutbeingtheoriginator.SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)8(GSM04.68version8.0.1Release1999)TheoriginatoroftheGCCtransactionchoosestheTransactionIdentifier(TI).AMSnotassumingtobetheoriginatorofthetransactionwillchosethetransactionidentifierreceivedfromthenetwork,settingtheTIflagto1+xmod2wherexisthereceivedTIflag.Thepresentdocumentdescribesthegroupcallcontrolprotocolonlywithregardtotwopeerentities,oneinaMS,theotheroneinthenetwork.Thecallcontrolentitiesaredescribedascommunicatingfinitestatemachineswhichexchangemessagesacrosstheradiointerfaceandcommunicateinternallywithotherprotocol(sub)layers.Inparticular,theGCCprotocolusestheMMandRRsublayerspecifiedinGSM04.08.Thisdescriptioninonlynormativeasfarastheconsequentialexternallyobservablebehaviourisconcerned.Forsimplicity,insteadofusingtheterms"GCCentityintheMS"and"GCCentityinthenetwork",thepresentdocumentoftenusestheterms"MS"and"network"ifnoconfusionmayarise.Certainsequencesofactionsofthetwopeerentitiescompose"elementaryprocedures"whichareusedasabasisforthedescriptioninthepresentdocument.Theseelementaryproceduresaredefinedinclause6.ThenetworkshouldapplysupervisoryfunctionstoverifythattheGCCproceduresareprogressingandifnot,takeappropriatemeanstoresolvetheproblems.This,however,isoutofthescopeofthepresentdocument.6ElementaryproceduresforGroupCallControl6.1Overview6.1.1GeneralTheelementaryproceduresmaybegroupedintothefollowingclasses:-groupcallestablishmentprocedures;-groupcallterminationprocedures;-callinformationphaseprocedures;-miscellaneousprocedures.Figure6.1givesanoverviewofthemainstatesandtransitionsontheMSside.SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)9(GSM04.68version8.0.1Release1999)*ifMSassumestobetheoriginatorofthegroupcall.**ifnotinRRconnectedmode.Figure6.1:Overviewgroupcallcontrolprotocol/MSsideSIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)10(GSM04.68version8.0.1Release1999)6.1.2Groupcallcontrolstates6.1.2.1GroupcallcontrolstatesattheMSsideoftheinterfaceTheGCCentityoftheMSisdescribedasanextendedfinitestatemachine.Itperformstransitionsbetween(main)states,andinmainstateGROUPCALLACTIVE(U3)itperformstransitionsbetweensub-states.Ithascertainparametersandattributes,e.g.configurationparametersandbehaviourparameters,whichitsetsandchangesbasedoninteractionwithhigherandlower(sub-)layersandonmessageexchangewithitspeerentity.Ifaconfigurationparameterissettoacertainvalue,theMSshallalsoadapttheconfigurationaccordingly.Behaviourparametersdecideon(partof)thebehaviouroftheGCCentity.WhentheGCCentityintheMSreceivesamessage,itshallfirstanalysewhetheritshallignorethemessage,seeclauses5and7.6.1.2.1.1AttributesandparametersofGCCintheMSForthefollowingbehaviourparameters,thedescriptionisinformative.ParameterDescriptionORIGDependingonthecontext,theMSassumestobetheoriginatorofthecall(ORIG=T)ornottobetheoriginatorofthecall(ORIG=F).COMMDependingonthecontext,theMSassumesthatcommunicationwithitspeerentityisenabledinbothdirections(COMM=T)ornot(COMM=F).ForthefollowingconfigurationparameterstheMSshalladaptitsconfigurationaccordingtotheparametervalueandparameterdefinition.ParameterDefinitionD-ATTD-ATT=TmeansthattheMSattachestheuserconnectionforthegroupcallinthedownlink.D-ATT=FmeansthattheMSdoesnotattachtheuserconnectionforthegroupcallinthedownlink.U-ATTU-ATT=TmeansthattheMSattachestheuserconnectionforthegroupcallintheuplink.U-ATT=FmeansthattheMSdoesnotattachtheuserconnectionforthegroupcallintheuplink.6.1.2.1.2NULL(U0)NogroupcallexistsfortheGCCentity.Whenenteringthestate,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:ORIG=F,COMM=F,D-ATT=F,U-ATT=F.6.1.2.1.3MMCONNECTIONPENDING(U0.p)TheGCCentityhasrequestedtheexplicitestablishmentofanMMconnection.Whenenteringthestate,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:ORIG=T,COMM=F,D-ATT=F,U-ATT=F.6.1.2.1.4GROUPCALLINITIATED(U1)TheGCCentityhasrequestedthepeerentityinthenetworktoestablishagroupcall.Whenenteringthestate,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:ORIG=T,COMM=T,D-ATT=F,U-ATT=F.SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)11(GSM04.68version8.0.1Release1999)6.1.2.1.5GROUPCALLACTIVE(U2)Thegroupcallisestablishedatleastinonecell;dependingonthesub-state,theMShasattachedtheuserconnectionintheuplinkand/ordownlink.Thefollowingsub-statesexist:-separatelink(U2sl);-waitforreceivemode(U2wr);-receivemode(U2r);-waitforsendandreceivemode(U2ws);-sendandreceivemode(U2sr);-nochannel(U2nc).6.1.2.1.6GROUPCALLPRESENT(U3)TheMShasreceivedanotificationaboutanongoinggroupcall.Higherlayersarerequestedtoacceptorrejectthecall.Whenenteringthestate,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:ORIG=F,COMM=F,D-ATT=F,U-ATT=F.6.1.2.1.7GROUPCALLCONNECTIONREQUESTED(U4)TheMShasreceivedanotificationaboutanongoinggroupcall.Higherlayershavedecidedtoacceptthecall.Whenenteringthestate,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:ORIG=F,COMM=F,D-ATT=F,U-ATT=F.6.1.2.1.8TERMINATIONREQUESTED(U5)TheMS(whichassumestobetheoriginatorofthegroupcall)hasbeeninstateU1orU2andhassentaTERMINATIONREQUESTmessagetothenetwork.Whenenteringthestate,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:ORIG=T,COMM=T,D-ATT=T,U-ATT=T.6.1.2.1.9Sub-statesoftheGroupcallactivestateNOTE:Controloftheuserconnectionattachmentisseenasagroupcallcontrolfunction.Thisisareasonwhythesub-statesaredistinguished.6.1.2.1.9.1separatelink(U2sl)AdedicatedonetooneRRconnectionexistsbetweenMSandnetwork.Whenenteringthesub-state,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:COMM=T,D-ATT=T,U-ATT=T.6.1.2.1.9.2waitforreceivemode(U2wr)TheMShasaskedthenetworktoenterreceivemodebutadedicatedone-to-onechannelisstillassigned.Whenenteringthesub-state,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:COMM=T,D-ATT=T,U-ATT=F.6.1.2.1.9.3receivemode(U2r)TheMSusesagroupcallchannel.Whenenteringthesub-state,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:COMM=F,D-ATT=T,U-ATT=F.SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)12(GSM04.68version8.0.1Release1999)6.1.2.1.9.4waitforsendandreceivemode(U2ws)TheMS(whichwasinU2rorU2wr)hasaskedfortheuplink.Whenenteringthesub-state,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:COMM=F,D-ATT=T,U-ATT=T.6.1.2.1.9.5sendandreceivemode(U2sr)TheMShasbeeninformedbyitspeerentitythattheuplinkisgranted.Whenenteringthesub-state,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:D-ATT=T,U-ATT=T.6.1.2.1.9.6nochannel(U2nc)TheGCCentityhasbeeninformedthatnochanneliscurrentlyavailable.TimerTnochannellisrunning.Whenenteringthesub-state,parametersshallbesettothefollowingvalues,andconfigurationshallbeadaptedtothenewvaluesofconfigurationparameters:COMM=F,D-ATT=T,U-ATT=T.6.1.2.1.10GCCTimersintheMSTable6.1specifiesthetimersusedinGCC.Thedenotationofcolumnsisdefinedasfollows:timer::=nameofthetimer;set::=underwhichconditionsthetimerisset(i.e.,started);stopped::=underwhichconditionsthetimerisstopped;runninginstate(s)::=inwhichstate(s)thetimermayberunning;actionatexpiry::=whichactionstheGCCentityshallperformatexpiry;value::=thedurationbetweensettingthetimerandexpiryofthetimer("s"denotes"second(s)""xx-yy"meansthatanyvaluebetweenxxandyyispermitted).Table6.1:SpecificationoftimersusedinGCCtimersetstoppedrunninginstate(s)actionatexpiryvalueTnochannelwhenenteringU2ncwhenleavingU2ncU2ncseesubclause6.3.13sTMM-estwhenenteringU0.pusingtheset-upprocedurewhenenteringU1usingtheimmediateset-upprocedurewhenleavingU0.porU1U0.p,U1seesubclause6.2.15sTtermwhensendingaTERMINATIONREQUESTwhenreceivingaTERMINATIONorTERMINATIONREJECTU5abortgroupcall10sTconnreqwhenenteringstateU4whenleavingstateU4U4abortgroupcall10-30s6.1.2.1.11ConsistencyofparametersandstatesTheMSshallconsiderthefollowingparametervaluesasinconsistentwiththestateorsub-state:ORIG=TisinconsistentwithstatesU3andU4.COMM=TisinconsistentwithstatesU0,U3,U4,andwithsub-statesU2ncandU2rofstateU2.SIST EN 300 948 V8.0.1:2003
ETSIETSIEN300948V8.0.1(2000-08)13(GSM04.68version8.0.1Release1999)AllothervaluesofparametersORIG,COMM,D-ATT,andU-ATTshallnotbeconsideredbytheMSasinconsistentwithastateorsub-state.6.1.2.2Groupcallcontrolstatesatthenetworksideoftheinterface6.1.2.2.1NULL(StateN0)NogroupcallexistsfortheGCCentity.6.1.2.2.2GROUPCALLINITIATED(N1)TheGCCentityhasreceivedtheindicationthatapeerentityinaMSwantstoestablishagroupcallforacertaingroupidentity.6.1.2.2.3GROUPCALLACTIVE(N2)Thegroupcallisestablishedinatleastonecell;theremaybeaMSwhichhasseizedtheuplinkornot;theremaybetalkingdispatchersornot.6.1.2.2.4GROUPCALLESTABLISHMENTPROCEEDING(N3)TheGCCentitywantstoacceptthegroupcall,hasinitiatedestablishmentofcorrespondinggroupcallchannels,and,ifthereisacallinguser.hassentaCONNECTmessagetothecallinguser(ifthereisacallinguser).6.1.2.2.5TERMINATIONREQUESTED(N4)TheGCCentityhasaskedlowersub-layerstoterminatethegroupcallinallcellsandwaitsforaconfirmationthatthegroupcallhasbeenterminatedinallcells.6.2Proceduresforestablishmentofagroupcall6.2.1ActivationofagroupcallbythenetworkTheGCCentityinthenetworkmayinitiatetheactivationofagroupcallwithacertaingroupcallreferenceandpriorityinalistofcellsbyaskinglowerlayerstoestablishthegroupcallwiththatgroupcallreferenceandpriorityinthosecells.Itthenwaitsuntilitisinformedbylower(sub-)layersthatresourceactivationwassufficientlysuccessful,andentersstateN2,GCACTIVE.6.2.2MobileoriginatedestablishmentHigherlayersintheMSmayasktheGCCentityinstateU0,NULL,toestablishagroupcall,eitherusingtheimmediateset-upprocedureorusingtheset-upprocedure.Therequestcontainsagroup-idandmaycontainapriorityindication.Onrequestofhigherlayerstoestablishagroupcallusingtheset-upprocedure,theGCCentityoftheMSbuildsanappropr
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