SIST EN 300 948 V7.0.1:2003
(Main)Digital cellular telecommunications system (Phase 2+) (GSM); Group Call Control (GCC) protocol (GSM 04.68 version 7.0.1 Release 1998)
- Abstract
Upgrade from Phase 2+ to Release 1998
- 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 V7.0.1:2003 is the SIST adoption of ETSI EN 300 948 V7.0.1, a European Telecommunications Standard for the Group Call Control (GCC) protocol in GSM Phase 2+. It specifies how a Mobile Station (MS) and the network set up, control, report on, and end Voice Group Call Service (VGCS) calls over the radio interface. Engineers, terminal and network vendors, and test labs use it to implement compatible GCC behaviour and message coding.
What does SIST EN 300 948 V7.0.1:2003 specify?
SIST EN 300 948 V7.0.1:2003 specifies the GCC protocol used by VGCS on the radio interface within digital cellular telecommunications system Phase 2+. Clause 4 states that support of the protocol is optional in both the MS and the network, so it is a capability standard rather than a universal mandatory feature.
The document is organized into references, definitions and abbreviations, applicability, main concepts, elementary procedures, error handling, message functional definitions, and the coding of information element value parts. Annex A is informative and records the change request history.
What are the key requirements of SIST EN 300 948 V7.0.1:2003?
SIST EN 300 948 V7.0.1:2003 models GCC as a pair of peer entities, one in the MS and one in the network, and treats them as communicating finite state machines. That matters because implementers must follow state transitions, not just message formats.
Main protocol behaviour
- Clause 5 places GCC in the Connection Management (CM) sublayer and states that higher layers and the MM sub-layer decide how parallel transactions are handled. In practice, the GCC implementation must fit into the wider GSM control stack.
- The group call may be initiated by a mobile user or by a dispatcher, but the dispatchers protocol is outside the scope of this document. This keeps the standard focused on radio-interface signalling.
State handling and timers
- Clause 6 defines MS states U0 to U5 and network states N0 to N4, plus sub-states of GROUPCALLACTIVE (U2). The state tells the implementation what it may send or accept at any moment.
- Clause 6 also defines timers Tnochannel, TMM-est, Tterm, and Tconnreq. These timers drive recovery, waiting periods, and abort actions, so they are central to interoperability.
Call establishment, active phase, and release
- Clause 6.2 distinguishes mobile-originated establishment by SETUP or IMMEDIATESETUP and mobile-terminating establishment by notification, join request, and transition into ACTIVE. This tells a terminal when to create an MM connection and when to join an existing group call.
- Clause 6.3 defines how the MS changes sub-state according to the RR mode, including separate link, receive mode, send and receive mode, and no channel. In practice, this controls when the user connection is attached in uplink and downlink.
- Clause 6.4 defines termination, abort, release, TERMINATION, TERMINATIONREQUEST, and TERMINATIONREJECT handling. This is the part implementers use for clean call teardown and for reacting to radio link failure.
Error handling and message exchange
- Clause 7 gives the MS rules for short messages, unknown transaction identifiers, unknown message types, mandatory IE errors, optional IE errors, and semantically incorrect messages. This is important for robust interworking and for future extensions.
- Clauses 8 and 9 define the message set and the coding of the information elements used by those messages.
What terms does SIST EN 300 948 V7.0.1:2003 define?
SIST EN 300 948 V7.0.1:2003 uses a small set of terms that are central to the protocol:
- Group Call Control (GCC) - the Layer 3 protocol that controls group call setup, active operation, and release.
- Voice Group Call Service (VGCS) - the service that uses GCC on the radio interface.
- Mobile Station (MS) - the terminal-side peer entity that sends and receives GCC messages.
- calling user - the GCC entity in the MS that initiates, or has initiated, the group call.
- originating MS - the MS treated as the originator of the group call; in some situations there may be one or none.
- group call channel - the combined uplink/downlink resource allocated per cell for a particular group call.
- Transaction Identifier (TI) - the identifier used to separate transactions; the originator chooses it.
Who uses SIST EN 300 948 V7.0.1:2003?
SIST EN 300 948 V7.0.1:2003 is used by GSM terminal vendors, radio-access network vendors, and protocol stack developers who need GCC interoperability. Test labs and conformance teams use it to check message content, state handling, and error reactions.
It is also relevant to buyers and quality managers for equipment that must support VGCS, because it defines the protocol behaviour expected at the radio interface. Network engineers use it when integrating group call features into GSM systems and when verifying MS-to-network signalling.
What changed in SIST EN 300 948 V7.0.1:2003 from the previous edition?
SIST EN 300 948 V7.0.1:2003 carries the Release 1998 upgrade. Annex A records change requests for corrections, GetStatus procedures, SetStatus procedures, and coding of the CallReference IE, followed by the version update to 7.0.1 for publication.
Which standards are used with SIST EN 300 948 V7.0.1:2003?
SIST EN 300 948 V7.0.1:2003 refers to these companion standards:
- GSM01.04 - abbreviations and acronyms used by the GSM specifications.
- GSM02.68 - VGCS Stage 1 service description.
- GSM03.03 - numbering, addressing, and identification, including group identity.
- GSM03.67 - enhanced Multi-Level Precedence and Pre-emption service, used for priority coding.
- GSM03.68 - VGCS Stage 2, which gives the service and call-control context.
- GSM04.06 - the MS-BSS data link layer.
- GSM04.07 - layer 3 general aspects, including message and IE handling.
- GSM04.08 - layer 3 specification for MM and RR, used here for connection setup, identities, and coding rules.
What does the SIST EN 300 948 V7.0.1:2003 document contain?
SIST EN 300 948 V7.0.1:2003 contains state-machine descriptions, protocol procedures, and message definitions for GCC. Clause 6 gives the MS and network states, sub-states, and timer behaviour, while clause 7 gives error-handling rules for abnormal or unknown protocol data.
Clauses 8 and 9 provide the message formats and the coding of value parts for Protocol Discriminator, Transaction identifier, MessageType, CallReference, Callstate, Cause, Originatorindication, SpareHalfOctet, and Stateattributes. These parts are what developers use when building parsers, encoders, test cases, and interoperability checks.
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Frequently Asked Questions
SIST EN 300 948 V7.0.1:2003 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 7.0.1 Release 1998)". This standard covers: Upgrade from Phase 2+ to Release 1998
Upgrade from Phase 2+ to Release 1998
SIST EN 300 948 V7.0.1:2003 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 V7.0.1:2003 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 7.0.1 Release 1998)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 7.0.1SIST EN 300 948 V7.0.1:2003en01-december-2003SIST EN 300 948 V7.0.1:2003SLOVENSKI
STANDARD
ETSIEN300948V7.0.1(2000-01)EuropeanStandard(Telecommunicationsseries)Digitalcellulartelecommunicationssystem(Phase2+);GroupCallControl(GCC)protocol(GSM04.68version7.0.1Release1998)GLOBALSYSTEMFORMOBILECOMMUNICATIONSRSIST EN 300 948 V7.0.1:2003
ETSIETSIEN300948V7.0.1(2000-01)2(GSM04.68version7.0.1Release1998)ReferenceREN/SMG-030468Q7KeywordsDigitalcellulartelecommunicationssystem,GlobalSystemforMobilecommunications(GSM)ETSIPostaladdressF-06921SophiaAntipolisCedex-FRANCEOfficeaddress650RoutedesLucioles-SophiaAntipolisValbonne-FRANCETel.:+33492944200Fax:+33493654716SiretN°34862356200017-NAF742CAssociationàbutnonlucratifenregistréeàlaSous-PréfecturedeGrasse(06)N°7803/88Internetsecretariat@etsi.frIndividualcopiesofthisETSIdeliverablecanbedownloadedfromhttp://www.etsi.orgIfyoufinderrorsinthepresentdocument,sendyourcommentto:editor@etsi.frImportantnoticeThisETSIdeliverablemaybemadeavailableinmorethanoneelectronicversionorinprint.Inanycaseofexistingorperceiveddifferenceincontentsbetweensuchversions,thereferenceversionisthePortableDocumentFormat(PDF).Incaseofdispute,thereferenceshallbetheprintingonETSIprintersofthePDFversionkeptonaspecificnetworkdrivewithinETSISecretariat.CopyrightNotificationNopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST EN 300 948 V7.0.1:2003
ETSI3ETSIEN300948V7.0.1(2000-01)(GSM04.68version7.0.1Release1998)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 V7.0.1:2003
ETSIETSIEN300948V7.0.1(2000-01)4(GSM04.68version7.0.1Release1998)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.208.2GETSTATUS.218.2.1mobileidentity.218.3IMMEDIATESETUP.218.3.1Mobileidentity.228.4SETPARAMETER.228.5SETUP.228.6STATUS.238.6.1Callstate.238.6.2Stateattributes.238.7TERMINATION.248.8TERMINATIONREJECT.248.9TERMINATIONREQUEST.249Contentsofinformationelementsvalueparts.259.1ProtocolDiscriminator.259.2Transactionidentifier.259.3MessageType.259.4Otherinformationelements.269.4.1CallReference.269.4.2Callstate.269.4.3Cause.279.4.4Originatorindication.289.4.6SpareHalfOctet.299.4.7Stateattributes.29AnnexA(informative):ChangeRequestHistory.30History.31SIST EN 300 948 V7.0.1:2003
ETSI5ETSIEN300948V7.0.1(2000-01)(GSM04.68version7.0.1Release1998)IntellectualPropertyRightsIPRsessentialorpotentiallyessentialtothepresentdocumentmayhavebeendeclaredtoETSI.TheinformationpertainingtotheseessentialIPRs,ifany,ispubliclyavailableforETSImembersandnon-members,andcanbefoundinSR000314:"IntellectualPropertyRights(IPRs);Essential,orpotentiallyEssential,IPRsnotifiedtoETSIinrespectofETSIstandards",whichisavailablefromtheETSISecretariat.LatestupdatesareavailableontheETSIWebserver(http://www.etsi.org/ipr).PursuanttotheETSIIPRPolicy,noinvestigation,includingIPRsearches,hasbeencarriedoutbyETSI.NoguaranteecanbegivenastotheexistenceofotherIPRsnotreferencedinSR000314(ortheupdatesontheETSIWebserver)whichare,ormaybe,ormaybecome,essentialtothepresentdocument.ForewordThisEuropeanStandard(Telecommunicationsseries)hasbeenproducedbytheSpecialMobileGroup(SMG).ThepresentdocumentspecifiestheGroupCallControl(GCC)protocolusedbytheVoiceGroupCallService(VGCS)ontheradiointerfacewithinthedigitalcellulartelecommunicationssystem(Phase2+).ThecontentsofthepresentdocumentissubjecttocontinuingworkwithinTC-SMGandmaychangefollowingformalTC-SMGapproval.ShouldTC-SMGmodifythecontentsofthepresentdocument,itwillberesubmittedforOAPbyETSIwithanidentifyingchangeofreleasedateandanincreaseinversionnumberasfollows:Version7.x.y7IndicatesGSMPhase2+Release1998;xtheseconddigitisincrementedforallchangesofsubstance,i.e.technicalenhancements,corrections,updates,etc.;ythethirddigitisincrementedwheneditorialonlychangeshavebeenincorporatedinthespecification.NationaltranspositiondatesDateofadoptionofthisEN:31December1999DateoflatestannouncementofthisEN(doa):31March2000DateoflatestpublicationofnewNationalStandardorendorsementofthisEN(dop/e):30September2000DateofwithdrawalofanyconflictingNationalStandard(dow):30September2000SIST EN 300 948 V7.0.1:2003
ETSIETSIEN300948V7.0.1(2000-01)6(GSM04.68version7.0.1Release1998)1ScopeThepresentdocumentspecifiestheGroupCallControl(GCC)protocolusedbytheVoiceGroupCallService(VGCS)ontheradiointerface.2ReferencesThefollowingdocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsofthepresentdocument.•Referencesareeitherspecific(identifiedbydateofpublication,editionnumber,versionnumber,etc.)ornon-specific.•Foraspecificreference,subsequentrevisionsdonotapply.•Foranon-specificreference,thelatestversionapplies.•Anon-specificreferencetoanETSshallalsobetakentorefertolaterversionspublishedasanENwiththesamenumber.•ForthisRelease1998document,referencestoGSMdocumentsareforRelease1998versions(version7.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.Forthepurposesofthepresentdocument,thefollowingtermsanddefinitionsapply.attachmentoftheuserconnection:SeeGSM04.08,subclause5.2.callinguser:GCCentityintheMobileStation(MS)initiatingorhavinginitiatedagroupcall.SIST EN 300 948 V7.0.1:2003
ETSI7ETSIEN300948V7.0.1(2000-01)(GSM04.68version7.0.1Release1998)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,thefollowingabbreviationapplies: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-oneormorethanoneGCCentitiesindifferentMSsengagedinagroupcall,andoneorenoneoftheMSsistheoriginatorofthegroupcall(calledtheoriginatingMSinthepresentdocument).Notethat,incertainsituations,aMSassumestobetheoriginatorofagroupcallwithoutbeingtheoriginator.SIST EN 300 948 V7.0.1:2003
ETSIETSIEN300948V7.0.1(2000-01)8(GSM04.68version7.0.1Release1998)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 V7.0.1:2003
ETSI9ETSIEN300948V7.0.1(2000-01)(GSM04.68version7.0.1Release1998)MMConnectionpending0.PGCpresent3Null0GCconnectionrequested4Null0GCinitiated1GCactiveTerminationrequested5States1,2,3,4?L:EST-CNF!H:SETUP-IND(g-id,prio)?L:SETUP-IND(g-id,prio)?H:ABORTREQ!L:JOINGCREQ(g-id)?H:JOINGCREQ?H:SETUP-REQ(g-id,prio)!L:EST-REQ(SETUP)?H:TERM.REQ!L:ABORT-REQ!H:TERM.CNF?H:ABORTREQ!L:ABORTREQ?H:IMMSETUPREQ(g-id,prio)!L:EST-REQ(IMMSETUP)or?TimeoutH!TERMCNF?L:DI(TERMINATION)or?L:DI(TERM.REQ)?H:TERM.REQ!L:DR(TERM.REQ)?H:TERM.REQ*!L:DR(TERM.REQ)?Tnochanceexp!L:ABORTREQ?H:ABORTREQ!L:ABORTREQ!H:JOINGCCNF(mode)?L:JOINGCCNF(mode)?L:DI(CONNECT)!H:SETUP-CNF(mode)[MM-est'd](Explicit)!H:TERM-IND?L:DI(TERMINATION)!L:ABORT-REQ**?L:MM-EST_REJ!H:TERM_CONFFigure6.1:Overviewgroupcallcontrolprotocol/MSside*ifMSassumestobetheoriginatorofthegroupcall**ifnotinRRconnectedmodeSIST EN 300 948 V7.0.1:2003
ETSIETSIEN300948V7.0.1(2000-01)10(GSM04.68version7.0.1Release1998)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 V7.0.1:2003
ETSI11ETSIEN300948V7.0.1(2000-01)(GSM04.68version7.0.1Release1998)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 V7.0.1:2003
ETSIETSIEN300948V7.0.1(2000-01)12(GSM04.68version7.0.1Release1998)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 V7.0.1:2003
ETSI13ETSIEN300948V7.0.1(2000-01)(GSM04.68version7.0.1Release1998)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.6.2.2Mobileoriginatedesta
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