SIST ETS 300 392-10-4 E2:2003

• Abstract:

  Analysis of predicted needs for digital trunked systems in Europe; definition of services to be provided; analysis of spectrum req ments; characteristics of relevant interfaces Contains: TETRA 03.60 to 03.85

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.070.10 - Terrestrial Trunked Radio (TETRA)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Mandate: T-172-1A
• Ref Project: ETSI ETS 300 392-10-4 ed.2 (2000-02) - Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 10: Supplementary services stage 1; Sub-part 4: Call Forwarding (CF)

SIST ETS 300 392-10-4 E2:2003 is the Slovenian adoption of ETS 300 392-10-4 Edition 2 from ETSI for Terrestrial Trunked Radio (TETRA) Voice plus Data (V+D). It specifies stage 1 supplementary services for Call Forwarding - Call Forwarding Unconditional (CFU), Call Forwarding Busy (CFB), Call Forwarding on No Reply (CFNRy), and Call Forwarding on Not Reachable (CFNRc) - plus the Forwarding Counter (FC) used to limit repeated forwarding during call set-up. The document is aimed at TETRA network planners, service providers, and implementers who need the user-visible behavior of call forwarding for circuit-mode services and SDS.

What does SIST ETS 300 392-10-4 E2:2003 specify?

SIST ETS 300 392-10-4 E2:2003 specifies how TETRA supplementary call forwarding services work at stage 1, meaning the service seen by users and network operators rather than protocol details. It covers CFU, CFB, CFNRy, CFNRc, and FC, and it applies to circuit mode V+D services and to Short Data Service (SDS) where stated.

The document also states what is not covered: Man Machine Interfaces and charging principles are outside its scope, and Selective Call Forwarding is not included.

The structure is straightforward:

• Clauses 1-3 set the scope, references, definitions, symbols, and abbreviations.
• Clause 4 gives the generic SS-CF specification shared by the forwarding services.
• Clauses 6-10 give the service-specific parts for CFU, CFB, CFNRy, CFNRc, and CFU for SDS.
• Clause 5 gives the overall SDL view of SS-CF.
• Annex A is a bibliography.

What are the key requirements of SIST ETS 300 392-10-4 E2:2003?

The most important requirement is that call forwarding is provided per ITSI, GTSI, or External Number, and may apply to all basic services or only selected ones. In practice, this means the same user can have different forwarding settings for speech and data, and a served user can keep originating calls while incoming calls are redirected.

SS-CF activation can be permanent or controlled by an authorized user, and the served user can enable or disable that authorized-user control. This matters because organizations can allow a dispatcher or other authorized user to manage forwarding, while still keeping the served user in control of who may do that.

The document requires a Forwarding Counter (FC) whenever repeated forwarding needs to be limited. FC starts from an initial value, increases at each accepted forwarding, and stops the call if the forwarding limit is reached. In practice, this prevents endless forwarding loops.

For forwarded calls, the network must notify both the forwarded-to user and the calling user according to the subscription options. The forwarded-to user can receive the original served user identity, the forwarding cause, the last forwarding number, or the last forwarding cause, while the calling user is told that forwarding happened. This is what makes forwarded calls understandable to both sides.

CFU applies to all basic circuit-mode V+D services, and also to SDS in its SDS-specific part. CFNRy uses an alerting timer in the range stated by the document and only applies when the call is alerted but not answered in time. CFNRc is the separate case where the user is not reachable, which is different from no reply because no alerting occurs.

Interactions are important in real deployments. CF takes precedence over Call Waiting (SS-CW) in several cases, interacts with Calling/Connected Line Identification Presentation and Restriction, and is constrained by Barring of Outgoing Calls (BOC) and Barring of Incoming Calls (BIC). The document also gives rules for Pre-emptive Priority Call, Call Completion services, and Mobility, so implementers can avoid conflicts between supplementary services.

What terms does SIST ETS 300 392-10-4 E2:2003 define?

• Additional network feature (ANF) - A capability beyond a basic service that is provided by the Switching and Management Infrastructure (SwMI), but not directly to a user.
• Served user - The user for whom the supplementary service is invoked.
• Forwarded-to user - The user to whom the call is redirected.
• Authorized user - The user allowed to define, activate, deactivate, and sometimes interrogate the service.
• Forwarding Counter (FC) - The counter that records how many forwarding events a call has encountered.
• Switching and Management Infrastructure (SwMI) - The TETRA network equipment, excluding subscriber terminals, that enables communication.
• Terrestrial Trunked Radio (TETRA) - The trunked radio system family this standard belongs to.
• Short Data Service (SDS) - The data service for which the CFU-for-SDS part of the document is written.

Who uses SIST ETS 300 392-10-4 E2:2003?

TETRA network operators and service providers use this standard to define how call forwarding is offered and controlled. SwMI vendors and system integrators use it to implement the user-facing behavior of forwarding, notifications, and service interactions. Quality managers, buyers, and test teams use it to check which forwarding cases, timers, identities, and precedence rules a TETRA implementation must support. Authorized users such as dispatchers may also use the service management functions described in the document.

What changed in SIST ETS 300 392-10-4 E2:2003 from the previous edition?

This second edition was redrafted from the latest published text of ECMA-173 to make it self-contained and easier to read. It adds TETRA-specific behavior, including group-call aspects and user situations not addressed in ECMA-173, and it distinguishes No Reply from Not Reachable because of the radio nature of TETRA links. The foreword also notes that SS-CD is not specified, and the document includes the Forwarding Counter.

Which standards are used with SIST ETS 300 392-10-4 E2:2003?

• ECMA-173 - The call diversion model used as a basis for this ETS.
• ITU-T Recommendation I.210 - Provides the service-description principles used for supplementary services.
• ITU-T Recommendation Z.100 - Defines Specification and Description Language (SDL), used for the dynamic models.
• ETS 300 392-2 - Defines TETRA Air Interface (AI) and the basic services that SS-CF relates to.
• CCITT Recommendation Q.9 - Provides vocabulary for switching and signalling terms.

What does the SIST ETS 300 392-10-4 E2:2003 document contain?

The document contains the generic SS-CF rules, four service-specific forwarding parts, and an SDS-specific forwarding part. It also includes SDL diagrams for SS-CF and FC, which are useful for implementation and verification work. Table 1 describes subscription options, and Table 2 lists mobility cases for serving, called, and forwarded-to users. Annex A provides supporting bibliography for related call-forwarding and TETRA work.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Radijska oprema in sistemi (RES) - Vseevropski prizemni snopovni radio (TETRA) - Govor in podatki (V+D) - 10. del: Dopolnilne storitve stopnje 1- 10-04. del: Izsmeritev klicaTerrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 10: Supplementary services stage 1; Sub-part 4: Call Forwarding (CF)33.070.10Prizemni snopovni radio (TETRA)Terrestrial Trunked Radio (TETRA)ICS:Ta slovenski standard je istoveten z:ETS 300 392-10-4 Edition 2SIST ETS 300 392-10-4 E2:2003en01-december-2003SIST ETS 300 392-10-4 E2:2003SLOVENSKI
STANDARD
EUROPEANETS300392-10-4TELECOMMUNICATIONFebruary2000STANDARDSecondEditionSource:TETRAReference:RE/TETRA-03001-10-04ICS:33.020Keywords:CF,data,radio,speech,stage1,supplementaryservice,TETRATerrestrialTrunkedRadio(TETRA);VoiceplusData(V+D);Part10:Supplementaryservicesstage1;Sub-part4:CallForwarding(CF)ETSIEuropeanTelecommunicationsStandardsInstituteETSISecretariatPostaladdress:F-06921SophiaAntipolisCEDEX-FRANCEOfficeaddress:650RoutedesLucioles-SophiaAntipolis-Valbonne-FRANCEInternet:[e-mail]-http://www.etsi.orgTel.:[phone]-Fax:[phone]CopyrightNotification:Nopartmaybereproducedexceptasauthorizedbywrittenpermission.Thecopyrightandtheforegoingrestrictionextendtoreproductioninallmedia.©EuropeanTelecommunicationsStandardsInstitute2000.Allrightsreserved.SIST ETS 300 392-10-4 E2:2003

Page2ETS300392-10-4:February2000Whilsteverycarehasbeentakeninthepreparationandpublicationofthisdocument,errorsincontent,typographicalorotherwise,mayoccur.Ifyouhavecommentsconcerningitsaccuracy,pleasewriteto"ETSIStandardsMakingSupportDept."attheaddressshownonthetitlepage.SIST ETS 300 392-10-4 E2:2003

Page3ETS300392-10-4:February2000ContentsForeword.71Scope.92Normativereferences.93Definitions,symbolsandabbreviations.103.1Definitions.103.2Symbols.123.3Abbreviations.123.3.1Supplementaryserviceabbreviations.124SS-CFGenericSpecification.124.1Description.134.1.1Generaldescription.134.1.2Applicability.134.2Procedures.134.2.1Provision/Withdrawal.134.2.2Normalprocedures.144.2.2.1Activation/deactivation/definition/registration/interrogation.144.2.2.1.1Activation/deactivation.144.2.2.1.2Enable/Disable.154.2.2.1.3Registration.164.2.2.1.4Interrogation.164.2.2.2Invocationandoperation.174.2.2.2.1Forwarded-touserCnotification.174.2.2.2.2CallinguserAnotification.174.2.3Exceptionalprocedures.184.2.3.1Activation/Deactivation.184.2.3.2Interrogation.184.2.3.3Invocationandoperation.194.3InteractionswithothersupplementaryservicesandANFs.194.3.1CallingLineIdentificationPresentation(SS-CLIP).194.3.2ConnectedLineIdentificationPresentation(SS-COLP).194.3.3Calling/ConnectedLineIdentificationRestriction(SS-CLIR/SS-COLR).194.3.4CallCompletiontoBusySubscriber(SS-CCBS).204.3.5CallCompletiononNoReply(SS-CCNRy).204.3.6Callreport.204.3.7Talkingpartyidentification.204.3.8Listsearchcall.204.3.9Shortnumberaddressing.204.3.10Areaselection.204.3.11Accesspriority.204.3.12Callwaiting.214.3.13Callhold.214.3.14Lateentry.214.3.15Transferofcontrol.214.3.16Prioritycall.214.3.17Pre-emptivePriorityCall.214.3.18Includecall.214.3.19Adviceofcharge.214.3.20Barringofoutgoingcalls.214.3.21Barringofincomingcalls.214.3.22Ambiancelistening.224.3.23Dynamicgroupnumberassignment.224.3.24InteractionwithANFMobility.224.4Inter-workingconsiderations.23SIST ETS 300 392-10-4 E2:2003

Page4ETS300392-10-4:February20005SS-CFoverallSDL.236SS-CFUSpecificSpecification.276.1Description.276.1.1Applicability.276.2InteractionwithothersupplementaryservicesandANFs.276.2.1CallWaitingSS-CW.276.2.2CallForwardingBusy(SS-CFB).276.2.3CallForwardingNoReply(SS-CFNRy).286.2.4CallForwardingnotReachable(SS-CFNRc).286.2.5Pre-emptivePriorityCall.286.2.6Callauthorizedbydispatcher.286.2.7Discreetlistening.287SS-CFBSpecificSpecification.287.1Description.287.1.1Generaldescription.287.1.2Applicability.287.2Procedures.297.2.1Provision/withdrawal.297.2.2Normalprocedures.297.2.2.1Activation/deactivation.297.3InteractionwithothersupplementaryservicesandANFs.297.3.1CallCompletiontoBusySubscriber(SS-CCBS).297.3.2CallCompletiononNoReply(SS-CCNR).297.3.3Pre-emptiveprioritycall.297.3.4CallForwardingUnconditional(SS-CFU).307.3.5CallForwardingNoReply(SS-CFNRy).307.3.6CallForwardingNotReachable(SS-CFNRc).307.3.7Callwaiting.307.3.8Discreetlistening.308SS-CFNRySpecificSpecification.308.1Description.318.1.1Generaldescription.318.1.2Applicability.318.2Procedures.318.2.1Provision/Withdrawal.318.2.2Normalprocedures.318.2.2.1Activation/Deactivation.318.2.2.2Invocationandoperation.318.2.3Exceptionalprocedures.318.2.3.1Activation/Deactivation.318.3InteractionwithothersupplementaryservicesandANFs.328.3.1CallCompletiontoBusySubscriber(SS-CCBS).328.3.2CallCompletiononNoReply(SS-CCNR).328.3.3CallForwardingUnconditional(SS-CFU).328.3.4CallForwardingBusy(SS-CFB).328.3.5CallForwardingNotReachable(SS-CFNRc).328.3.6Callauthorizedbydispatcher.328.3.7Callwaiting.328.3.8Pre-emptiveprioritycall.339SS-CFNRcSpecificSpecification.339.1Description.339.1.1Generaldescription.339.1.2Applicability.339.2Procedures.339.2.1Provision/withdrawal.339.2.2Normalprocedures.339.2.2.1Activation/deactivation/registration/interrogation.339.2.2.2Invocationandoperation.339.2.3Exceptionalprocedures.34SIST ETS 300 392-10-4 E2:2003

Page5ETS300392-10-4:February20009.2.3.1Activation/Deactivation.349.3InteractionswithothersupplementaryservicesandANFs.349.3.1Interactionswithothersupplementaryservices.349.3.2InteractionwithCallWaiting(SS-CW).349.3.3InteractionwithANFMobility.349.4Inter-workingconsiderations.3410SS-CFUforSDSSpecification.3410.1Description.3410.1.1Generaldescription.3410.1.2Applicability.3510.2Procedures.3510.2.1Provision/withdrawal.3510.2.2Normalprocedures.3510.2.2.1Activation/deactivation/registration/interrogation.3510.2.2.1.1Enable/Disable.3610.2.2.1.2Registration.3610.2.2.1.3Interrogation.3710.2.2.2Invocationandoperation.3710.2.3Exceptionalprocedures.3710.2.3.1Activation/Deactivation.3710.3InteractionswithothersupplementaryservicesandANFs.3710.3.1Interactionswithothersupplementaryservices.3710.3.2InteractionwithANFMobility.3710.4Inter-workingconsiderations.38AnnexA(informative):Bibliography.39History.40SIST ETS 300 392-10-4 E2:2003

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Page7ETS300392-10-4:February2000ForewordThisEuropeanTelecommunicationStandard(ETS)hasbeenproducedbytheTerrestrialTrunkedRadio(TETRA)ProjectoftheEuropeanTelecommunicationsStandardsInstitute(ETSI).ThisETSisamulti-partstandardandwillconsistofthefollowingparts:Part1:"Generalnetworkdesign";Part2:"AirInterface(AI)";Part3:"InterworkingattheInter-SystemInterface(ISI)";Part4:"Gatewaysbasicoperation";Part5:"PeripheralEquipmentInterface(PEI)";Part6:"LineconnectedStation(LS)";Part7:"Security";Part9:"Generalrequirementsforsupplementaryservices";Part10:"Supplementaryservicesstage1";Part11:"Supplementaryservicesstage2";Part12:"Supplementaryservicesstage3";Part13:"SDLmodeloftheAirInterface(AI)";Part14:"ProtocolImplementationConformanceStatement(PICS)proformaspecification".TranspositiondatesDateofadoptionofthisETS:21January2000DateoflatestannouncementofthisETS(doa):30April2000DateoflatestpublicationofnewNationalStandardorendorsementofthisETS(dop/e):31October2000DateofwithdrawalofanyconflictingNationalStandard(dow):31October2000SIST ETS 300 392-10-4 E2:2003

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Page9ETS300392-10-4:February20001ScopeThisETSspecifiesthesupplementaryservicesCallForwardingUnconditional(CFU),CallForwardingBusy(CFB),CallForwardingonNoReply(CFNRy)andCallForwardingonNotReachable(CFNRc)whichareapplicabletovariousbasicservicessupportedbyTETRASwMIs.BasicservicesarespecifiedinETS300392-2[4].SS-CFU,SS-CFB,SS-CFNRyandSS-CFNRcaresupplementaryserviceswhichapplyduringcallestablishmentprovidingaforwardingofanincomingcalltoanotherdestinationthantheoriginaldestinationdefinedbythecallinguserunderdifferentconditions(busy,noreplyornotreachable)orundernocondition(unconditional).Supplementaryservicesspecificationsareproducedinthreestages,accordingtothemethoddescribedinITU-TRecommendationI.210[2].Thepresentdocumentcontainsthestage1specificationsofSS-CFU,SS-CFB,SS-CFNRyandSS-CFNRc.Thestage1descriptionsspecifythesupplementaryservicesasseenbyusersofnetworks.ThisETSisapplicabletocircuitmodeTETRAV+Dtele-servicesandbearerservices.ThisETSisalsoapplicabletoTETRAShortDataService(SDS).ManMachineInterfacesandchargingprinciplesareoutsidethescopeofthisETS.SelectiveCallForwardingisoutsidethescopeofthisETS.NOTE1:SelectiveCallForwardingmaybeconsideredforfurtherimprovementsofTETRASS-CFatalaterstage.ThissecondeditionofthisETSwaspresentedasadeltadocumenttothefirsteditionofECMA-173[1].ThissecondeditionhasbeenredraftedbasedonthelatestpublishedtextofECMA-173[1]asaselfcontaineddocumentsoastobemorereadable.AdditionstoECMA-173[1]havebeenmadetotakeintoaccountparticularTETRAspecificssuchasgroupcallsandtoincludeuserrequirementsandsituationsnotaddressedinECMA-173[1].NOTE2:ContrarytoECMA-173[1],thisETSdoesnotspecifySS-CD(CallDeflection)whichisnotpresentlysupportedbyTETRA.NOTE3:ContrarytoECMA-173[1],thisETSdistinguishesbetweenNoReplyandNotReachablebecauseoftheradionatureoftheTETRAlinks.ThisStandardspecifiesalsotheForwardingCounter(FC),whichisapplicabletovariousbasicservicessupportedbyTETRANetworks.BasicservicesarespecifiedinETS300392-2[4].FCcountsthenumberofforwardingthatacallhasbeenforwardedandallowstolimitthenumberofforwardingthatacallrequestmayencounterduringcallestablishment,e.g.toprotectthenetworkagainstindefinitelooping.Thereisnouserinvolvedintheprovisionoroperationofforwardingcounter.2NormativereferencesThisETSincorporatesbydatedandundatedreference,provisionsfromotherpublications.Thesenormativereferencesarecitedattheappropriateplacesinthetextandthepublicationsarelistedhereafter.Fordatedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisETSonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthepublicationreferredtoapplies.[1]ECMA-173(1997):"PrivateIntegratedServicesNetwork(PISN)-Specification,FunctionalModelandInformationFlows-CallDiversionSupplementaryServices(CFSD)".[2]ITU-TRecommendationI.210(1993):"PrinciplesoftelecommunicationservicessupportedbyanISDNandthemeanstodescribethem".SIST ETS 300 392-10-4 E2:2003

Page10ETS300392-10-4:February2000[3]ITU-TRecommendationZ.100(1993):"CCITTSpecificationanddescriptionlanguage(SDL)".[4]ETS300392-2(1995):"TerrestrialEuropeanTrunkedRadio(TETRA);VoiceplusData(V+D);Part2:AirInterface(AI)".[5]CCITTRecommendationQ.9(1988):"Vocabularyofswitchingandsignallingterms".3Definitions,symbolsandabbreviations3.1DefinitionsForthepurposesofthisETS,thefollowingtermsanddefinitionsapply:Additionalnetworkfeature:additionalnetworkfeature(ANF)isacapability,overandabovethatofabasicservice,providedbyaSwMI,butnotdirectlytoaSwMIuser.Authorizeduser:userwhoisresponsibleforthedefinition,activationanddeactivationoftheservice.Theauthorizedusermayalsointerrogatetheservice.Affecteduser:userwhoissubjecttotheoperation.Busy:TETRAdestinationisconsideredtobebusyifeithera"networkdetermineduserbusy"ora"userdetermineduserbusy"conditionexists.Call,basiccall:callorbasiccallisaninstanceoftheuseofabasicservice.Connectednumber:numberoftheuserthatanswers(UserC).Forwarded-tonumber:forwarded-tonumberisthenumbertowhichacallisforwarded.Forwarded-touser:forwarded-touseristheusertowhichacallisforwarded.Forwarding:forwardingistheredirectionofacall,onbehalfofacalleduserandpriortoconnect,toanumberdifferentfromthenumberofthatcalleduser.Forwardingcause:forwardingcausecontainsthereasonfortheforwarding:CFU,CFB,CFNRy,CFNRc.Forwardingcounter:counterforthenumberofforwardinginvolvedinacallorsignallingconnectionduringtheestablishmentphase.Forwardingnumber:forwardingnumberisthenumberoftheserveduser.Forwardinguser:userforwhichthecallforwardingisinvoked;itmaybethecalleduserfirstandthenanyofthesuccessiveforwarded-tousers(seealsolastforwardinguser).Forwardswitching:networkrouteingalgorithmwhichperformstheforwardingbyjoiningtogetherthefirstconnectionfromUserA'snodetoUserB'snodeandasecond,newconnectionfromUserB'snodetoUserC'snode.Lastforwardinguser:lastforwardinguseristheserveduserfromthepointofviewoftheforwarded-touserforaparticularstageofcallforwarding.Inthecaseofacallsubjecttoasinglestageofcallforwarding,UserBisthelastforwardinguserfromthepointofviewofUserC.Inthecaseofacallsubjecttomultiplestagesofcallforwarding,userB1isthelastforwardinguserfromthepointofviewofuserB2,userB2isthelastforwardinguserfromthepointofviewofuserB3,etc.TheserveduserforthefinalstageofcallforwardingisthelastforwardinguserfromthepointofviewofUserC.LineStation(LS):physicalgroupingthatcontainsallthefixedequipmentthatisusedtoobtainTETRAservicesthroughaline.SIST ETS 300 392-10-4 E2:2003

Page11ETS300392-10-4:February2000MobileStation(MS):physicalgroupingthatcontainsallofthemobileequipmentthatisusedtoobtainTETRAservices.Bydefinition,amobilestationcontainsatleastoneMobileRadioStack(MRS).Originalcallednumber:originalcallednumberisthenumberofUserB(incaseofmultiplecallforwardinguserB1).Originalcalleduser:originalcalleduseristhefirstserveduserofacallwhichissubjecttooneormorestagesofcallforwarding,i.e.UserBorB1.Partialre-routeing:networkrouteingalgorithmwhichperformsthecallforwardingbyreplacingaparticularpartoftheconnectionfromUserA'snodetoUserB'snodebyanotherconnectionfromUserA'snodetoUserC'snode.Signallingconnection:connectionusedtoexchangeinformationbetweenpeersupplementaryserviceprotocolcontrolentitiesindependentlyofabasiccall.Supplementaryservice:anyserviceprovidedbyanetworkinadditiontoitsbasicserviceorservices(definedinCCITTRecommendationQ.9[5]).Asupplementaryservicemodifiesorsupplementsabasictelecommunicationservice.Consequently,itcannotbeofferedtoacustomerasastandaloneservice.Itmustbeofferedtogetherwithorinassociationwithabasictelecommunicationservice(extractfromITU-TRecommendationI.210[2]).SwitchingandManagementInfrastructure(SwMI):alloftheTETRAequipmentforaVoiceplusData(V+D)networkexceptforsubscriberterminals.TheSwMIenablessubscriberterminalstocommunicatewitheachotherviatheSwMI.SwMInumber:SwMInumberisanumberbelongingtoaSwMInumberingplan.Re-routeing:networkrouteingalgorithmwhichperformsthecallforwardingbyreplacingtheconnectionfromUserA'snodetoUserB'snodebyanotherconnectionfromUserA'snodetoUserC'snode.Serveduser:serveduseristheuserofaparticularSwMInumberwhoisrequestingthatcallstohisnumberbeforwarded.Thisusermayalsobereferredtoastheforwardinguserorthecalleduser.Tele-service:typeoftelecommunicationsservicethatprovidesthecompletecapability,includingterminalequipmentfunctions,forcommunicationbetweenusersaccordingtoagreedprotocols.Serveduser:userforwhomthesupplementaryserviceisinvoked.User:entityusingtheservicesofatelecommunicationsnetworkviaanexternallyaccessibleserviceaccesspoint.Unlessotherwisenoted,theworduseristobeunderstoodasindividualorgroup.NOTE1:Ausermaybeapersonoranapplicationprocess.Userapplication:applicationprocesswhichactsasauser(seedefinitionofuserjustabove).UserA:userAisthecallinguserofacallwhichissubjecttocallforwarding.UserB:userBistheserved(forwarding)userofacallwhichissubjecttocallforwarding.UserB1,userB2,userB3,etc.:thesearetheserved(forwarding)usersofacallwhicharesubjecttomultiplestagesofforwarding.B1isthefirstserveduser,B2isthesecondserveduser,B3isthethirdserveduser,etc.NOTE2:B2isalsotheforwarded-touserwithrespecttothefirststageofcallforwarding,B3isalsotheforwarded-touserwithrespecttothesecondstageofcallforwarding,etc.UserC:userCistheforwarded-touserwithrespecttothefinalstageofcallforwarding.SIST ETS 300 392-10-4 E2:2003

Page12ETS300392-10-4:February20003.2SymbolsForthepurposesofthisETS,therearenoadditionalsymbolsexceptedthesymbolsusedintheSDLrepresentation(ITU-TRecommendationZ.100[3]).3.3AbbreviationsForthepurposesofthisETS,thefollowingabbreviationsapply:ANFAdditionalNetworkFeatureCDCallDeflectionFCForwardingCounterGTSIGroupTETRASubscriberIdentityISDNIntegratedServicesDigitalNetworkISIInterSystemInterfaceITSIIndividualTETRASubscriberIdentityLSLineStationMSMobileStationSDLSpecificationandDescriptionLanguageSDSShortDataServiceSSSupplementaryServiceNOTE:TheabbreviationSSisonlyusedwhenreferringtoaspecificsupplementaryservice.SwMISwitchingandManagementInfrastructureTETerminalEquipmentTETRATerrestrialEuropeanTrunkedRadioV+DVoicePlusData3.3.1SupplementaryserviceabbreviationsBICBarringofIncomingCallsBOCBarringofOutgoingCallsCADCallAuthorizedbyDispatcherCCBSCallCompletiontoBusySubscriber(TETRA)CCNRCallCompletiononNoReply(TETRA)CFCallForwardingCFBCallForwardingonBusyCFNRCallForwardingonNoReply(genericforbothCFNRyandCFNRc)CFNRcCallForwardingonNotReachableCFNRyCallForwardingonNoReplyCFUCallForwardingUnconditionalCLIPCallingLineIdentificationPresentationCLIRCalling/ConnectedLineIdentificationRestrictionCOLPCOnnectedLineIdentificationPresentationCOLRCOnnectedLineIdentificationRestrictionCRCallReportCWCallWaitingDLDiscreetListeningICIncludeCallPPCPre-emptivePriorityCallSNAShortNumberAddressing4SS-CFGenericSpecificationThisgenericspecificationregroupsallelementscommontothefourCallForwardingprocedures(CFU,CFB,CFNRyandCFNRc).Eachcallforwardingprocedurehasthenitsowndedicatedpart.SS-CFUforSDSisdescribedinanotherspecificpart.FCshallbeinvokedinconjunctionwithacallforwardingrequestwhenitisdesiredtolimitthenumberofforwardingthatthecallcanencounter.Themaximumnumberofforwardingthatthecallcanencounterisnetworkdependent,intherange1to31.SIST ETS 300 392-10-4 E2:2003

Page13ETS300392-10-4:February20004.1Description4.1.1GeneraldescriptionSS-CFenablesaservedusertohavethenetworkredirect,toeitheranotherITSIortoanotherGTSI,callswhichareaddressedtotheserveduser'sITSI/GTSI/ExternalNumber.SS-CFmayoperateonallcallsorjustthoseassociatedwithspecifiedbasicservices.Theserveduser'sabilitytooriginatecallsisunaffectedbySS-CF.SS-CFisprovidedonaperITSI/GTSI/ExternalNumberbasis.Themaximumnumberofforwardingforasinglecallisanetworkimplementationoption.Whencountingthenumberofforwarding,alltypesofforwardingshallbeincluded.NOTE1:Notseentotheuser,themechanismoftheForwardingCounterallowstocountthenumberofforwardingofthecallresourceandofthesignalingconnection.NOTE2:ThemechanismoftheTransitCounterisseparatebutsimilartotheForwardingCountermechanism.CallforwardingofanindividualcallmaybeeithertoanITSIortoaGTSI;individualandgroupcallsmaybeforwardedtoeitheranITSIoraGTSI(i.e.theCommunicationTypeasdefinedinETS300392-2[4]subclause14.8.2maychangeduetoforwarding).Inthecaseoftheset-upofagroupcall,theinvocationofSS-CFbyanindividualmemberofthegrouphasnoeffectonthegroupcallset-upandthegroupcallshallnotbeforwardedtoanonmemberofthegroup.NOTE3:Asaresultofcallforwarding,theoriginalTETRAcallmaybeforwardedtoanexternalnumber.4.1.2ApplicabilitySS-CFisapplicabletoallbasicTETRAV+Dcircuitmodeservicesasdefinedinsubclause11.3.4ofETS300392-2[4](speechanddata).FCisapplicabletoallbasicservicesdefinedinETS300392-2[4].4.2Procedures4.2.1Provision/WithdrawalProvisionandwithdrawalofSS-CFshallbebypre-arrangementwiththeserviceprovider.SS-CFsubscriptionshallbeonaperITSI/GTSI/ExternalNumberbasis.ForeachITSI/GTSI/ExternalNumber,thesupplementaryservicemaybesubscribedtocollectivelyforallbasicservicessubscribedtoatthatITSI/GTSI/ExternalNumberorforonlysomeofthebasicservicessubscribedtoatthatITSI/GTSI/ExternalNumber.ThesubscriptionoptionsandvaluesofferedbytheoriginatingSwMIareanimplementationmatter.Astage3standardshallsupporttheoptionsandvaluesspecifiedintable1.ASwMImayofferlessoptionsandvaluesthanthosespecifiedintable1.SubscriptionoptionsapplyseparatelytoeachbasicservicesubscribedtooneachITSI/GTSI/ExternalNumber.Foreachsubscriptionoptiononlyonevalueistobeselected.DifferentsubscriptionoptionsmaybeappliedtodifferentservicesforthesameITSI/GTSI/ExternalNumber,e.g.SS-CFforVoicemayhavedifferentsubscriptionoptionthanSS-CFforDataforthesameITSI/GTSI/ExternalNumber.SubscriptionoptionsforonecallforwardingsupplementaryservicemaybedifferentfromcorrespondingsubscriptionoptionsforanothercallforwardingsupplementaryservicesforthesameITSI/GTSI/ExternalNumber.Anyforwarded-tousershallbeabletodeactivateselectivelycallforwardingforwhichthatuserisaforwarded-touser;thisdeactivationshallbepossibleonlyfortheservicesandthecallforwardingproceduresthataffecttheforwarded-touser.SIST ETS 300 392-10-4 E2:2003

Page14ETS300392-10-4:February2000ContrarytoECMA-173[1],inthecaseofTETRA,theserveduserdoesnotobtainanindicationthatSS-CFiscurrentlyactivatedwhenplacinganoutgoingcallandthisisnotasubscriptionoption.ContrarytoECMA-173[1],theserveduser/forwardinguserdoesnotreceivenotificationthatacallhasbeenforwarded;thisappliesalsotoalltheintermediateservedusers/forwardingusers.Table1:SubscriptionoptionsSubscriptionOptionsValuePermanentactivation-Yes-NoCallinguserreceivesnotificationthatcallhasbeenforwarded-Yeswithoutforwarded-toITSI/GTSI/ExternalNumber(note)ServeduserreleaseshisITSI/GTSI/ExternalNumbertoforwarded-touser-No-YesNOTE:ForTETRA,notactuallyasubscriptionoption.FCshallbegenerallyavailableforallcallsthatinvolvemultiplecallforwarding.NOTE:"Local"aswellas"remote"needstobecounted;localcallsarewithinaSwMI;localcallsmayencountercallforwardingandneedtobeaccountedforaswell.4.2.2Normalprocedures4.2.2.1Activation/deactivation/definition/registration/interrogation4.2.2.1.1Activation/deactivationWithintheTETRAnetworkenvironment,theactivationupondefinitionshallbeused.SS-CFmaybeeitherpermanentlyactivatedoractivated/deactivatedunderusercontrol.Ifactivation/deactivationisunderusercontrol,theSwMImayprovideforactivation/deactivationbyanyauthorizeduser(serveduserornot).InthecaseofSS-CFinvolvingaserveduserbeingaservedgroup,SS-CFmaybepermanentlyactivatedforthatgroupGTSIormaybeactivated/deactivatedbyanauthorizedusermemberornotofthegroup.Amemberofagroupshallnotbeabletoactivate/deactivateSS-CFforthegroupheismemberofunlessheisanauthorizeduser.Incasethereisonlyoneauthorizeduser,itshallbetheserveduser;inothercases,theotherauthorizedusersaredifferentfromtheserveduserandtheservedusermayhavelimitedauthorizedusercapability.Anyauthorizedusermayactivateand/ordeactivateSS-CFfortheserveduser.NOTE1:Criteriaforattributionsofauthorizeduserstatusshallbeimplementationdependent(e.g.dispatchersmaybeauthorized).AnyauthorizedusershallbeabletoactivateSS-CFseparatelyforeachbasicserviceforwhichSS-CFissubscribedtoandtherebyrequestadifferentforwarded-toITSI/GTSI/ExternalNumberforeachbasicserviceforwhichSS-CFissubscribedto;anyauthorizedusershallalsobeabletoactivateSS-CFforallbasicservicesforwhichSS-CFissubscribedto(inwhichcaseasingleITSI/GTSI/ExternalNumbershallbeusedasforwarded-tonumberforallbasicservices).SIST ETS 300 392-10-4 E2:2003

Page15ETS300392-10-4:February2000AnyauthorizedusermayactivateSS-CFattheservedusersuchthattheactivating(e.g.authorizeduser)userbecomestheforwarded-touser.Theserveduser(andonlytheserveduser)shallbeabletoenableandtodisableauthorizeduseractivation/deactivation.Theintendedforwarded-touserwhoisalsoauthorizedusershallbeabletoactivateSS-CFregardlessofwhetherSS-CFisalreadyactiveornot.Theservedusermaydisableanauthorizeduseractivationatanytime.Anyforwarded-tousershallbeabletobecomeanauthorizeduserforthedeactivationofSS-CFforthebasicservicesandtheforwardingproceduresforwhichthisuserisdefinedasaforwarded-touser.Theservedusershallnotbeabletodisablethatdeactivationcapabilitybytheforwarded-touser.Theauthorizedforwarded-tousermaydeactivateSS-CFattheserveduser.Thisshallnotbedependentonwhethertheserveduserhasenabledauthorizeduseractivation.Theforwarded-tousermaybedefinedasatemporaryauthorizeduser;theforwarded-tousershalllosethisauthorizedusercapabilityassoonasSS-CFisdeactivatedinthisway,andshallnotregainthecapabilityifSS-CFisactivatedagaintoadifferentforwarded-touser.Theforwarded-touser,atthesametimeasdeactivatingSS-CFasdescribedabove,maybeabletoactivateSS-CFfromtheservedusertoanotherforwarded-touser(i.e.changethedestinationofSS-CF).Theforwarded-tousershalllosethisauthorizedusercapabilityassoonasSS-CFisreactivatedinthisway.Thenewforwarded-tousershallgainthisauthorizedusercapability.Whenanactivation/deactivationprocedureisperformedsuccessfullybyanauthorizeduser,theserveduserandtheactivating/deactivatingauthorizedusershallbenotified.ThenotificationtotheservedusershallincludetheITSI/GTSI/ExternalNumberoftheforwarded-touserandthebasicservices.NOTE2:Theauthorizedusergetsthesamenotificationaspartoftheactivationprocedure.Itshallbepossible,thattheserveduseractivatesSS-CFandtheauthorizeduserdeactivatesSS-CFandviceversa.Itshallbepossible,thattheauthorizeduserwhodeactivatesSS-CFbedifferentfromtheauthorizeduserwhoactivatedSS-CFandvice-versa.NOTE3:Theuseofapasswordfacilityforauthorizeduseractivationasanimplementationoptionisnotexcluded.4.2.2.1.2Enable/DisableTheserveduser(andonlytheserveduser)shallbeabletoenable/disableanyauthorizeduseractivationwhentheauthorizeduserisdifferentfromtheserveduser.Theservedusershallbeabletoenable/disableanyauthorizeduserdeactivationiftheauthorizeduserisnottheforwarded-touserforthatSS-CFprocedureandforthosebasicservices.ToactivateSS-CF,theauthorizedusershall:1)definetheforwarded-touserITSI/GTSI/ExternalNumber;2)indicatethecircuitmodeforwhichitapplies(i.e.ifSS-CFappliestospeechcallsand/ortodatacalls);thiscorrespondsinfacttothedefinitionproceduredefinedinsubclause14.3.1.5ofETS300392-1[3].NOTE:Verificationthattheforwarded-touserITSI/GTSI/ExternalNumberexistsandthatthespecifiedbasicserviceissubscribedtoatthatITSI/GTSI/ExternalNumbermaybecarriedoutbeforeacceptingtheSS-CFactivationrequest.ThisverificationisoutsidethescopeofthisETS.Theserviceprovidershallreturnnotificationofacceptanceoftherequest.NotificationofacceptanceshallincludetheITSI/GTSI/ExternalNumberoftheforwarded-tousertowhomtheSS-CFisactive.Intheabsenceofanyoftheparametersintheactivationprocedure(e.g.theforwarded-toITSI/GTSI/ExternalNumber),defaultparametersalreadyknowntotheSwMImaybeused.Intheabsenceofbasicserviceinformationprovidedbytheuser,theactivationwillbevalidforallbasicservices.SIST ETS 300 392-10-4 E2:2003

Page16ETS300392-10-4:February2000ItshallbepossibletodeactivateSS-CFbymeansofanexplicitrequestfordeactivation.Anexplicitrequestfordeactivationshallbetreatedasfollows:-ifdeactivationofSS-CFforanindividualbasicserviceisrequested,itshallbeacceptedonlyifSS-CFisalreadyactivatedforthatbasicservice;-ifdeactivationofSS-CFcollectivelyforallbasicservicesisrequested,itshallresultinthediscardingofanyforwarded-toITSI/GTSI/ExternalNumbersforindividualbasicservicesandanyforwarded-toITSI/GTSI/ExternalNumbercollectivelyforallbasicservices.ItshallbepossibletodeactivateSS-CFbyactivatingSS-CFtoadifferentforwarded-toITSI/GTSI/ExternalNumber.ArequestforactivationofSS-CFwhenSS-CFisalreadyactivatedshallbetreatedasfollows:-ifactivationofSS-CFforanindividualbasicserviceisrequested,itshallbeacceptedonlyifSS-CFisnotalreadyactivatedcollectivelyforallbasicservicesand,ifSS-CFisalreadyactivatedforthatindividualbasicservice,shallresultintheoverwritingoftheexistingforwarded-toITSI/GTSI/ExternalNumber;-ifactivationofSS-CFcollectivelyforallbasicservicesisrequested,itshallresultinthediscardingofanyexistingforwarded-toITSI/GTSI/ExternalNumbersforeachbasicserviceandtheoverwritingofanyexistingforwarded-toITSI/GTSI/ExternalNumbercollectivelyforallbasicservices.ContrarytoECMA-173[1],inthecasewhereafirstcallforwardingrequesttoafirstfunctionalentityfails,itshallnotbepossibletorequestasecondcallforwardingagainstasecondfunctionalentity.FCshallbeinvokedinconjunctionwithacallforwardingrequest.Wheninvoked,theforwardingcountershallbesettoaninitialvalueandthenincrementedeachtimethatthecallforwardingrequestisaccepted.Theinitialvalueshallbezerounlessanyknowledgeavailableaboutthehistoryofthecall(e.g.routetaken,inter-working,diversions)isusedtochooseahigherinitialvalue.FCshallterminatewhenthecallrequestreachesitsdestination,isreleased,orleavestheTETRANetwork.4.2.2.1.3RegistrationRegistrationofinformationisperformedbysubscriptionand/oronactivationofSS-CF.Therearenoseparateregistrationprocedures.4.2.2.1.4InterrogationTheSwMImayprovideinterrogationtotheserveduserandtoanyauthorizeduser;theforwarded-tousermaybedefinedasatemporaryauthorizeduser.InthecaseofSS-CFinvolvingaserveduserbeingaservedgroup,SS-CFinterrogationmaybeoperatedbyanyauthorizedusereitherinsideoroutsidethegroup.AmemberofaservedgroupshallnotbeabletointerrogateSS-CFforthegroupheismemberofunlessheisanauthorizeduser.Ifinterrogationisprovided,aSwMIshallsupportinterrogationonaperITSI/GTSI/ExternalNumberbasisforallbasicservicesand/orforauserspecifiedbasicservice.TheSwMIresponsetoaninterrogationrequestshallprovidethefollowinginformationtotheuser:-activatedordeactivatedstateofthesupplementaryservice;-ifactivated:-forwarded-toITSI/GTSI/ExternalNumber;-whetheractivatedforallbasicservicesoranindividualbasicserviceandtheidentityoftheindividualbasicservice.Asadditionalinformation,theinterrogationmayprovideinformationtotheserveduser,whetheractivationbyanauthorizeduserhasbeenenabled.SIST ETS 300 392-10-4 E2:2003

Page17ETS300392-10-4:February2000WhereinterrogationisforallbasicservicesforwhichSS-CFissubscribedtoandSS-CFhasbeenactivatedseparatelyformorethanonebasicservice,theaboveinformationshallberepeatedforeachactivation(e.g.twice,onceforspeechandoncefordata).Ifinterrogationbyauserdifferentfromtheserveduserisprovided,itshallbepossiblefromthefollowingusers:-anyauthorizedusermayinterrogateSS-CFconditionsontheserveduser.Authorizationshallbeimplementationdependent(e.g.dispatchersmaybeauthorized);-theforwarded-tousermayinterrogateSS-CFattheserveduser(butonlyforthoseoptionsforwhichheistheforwarded-touser).TheauthorizeduserinterrogationrequestandresponseshallincludetheinformationasspecifiedfortheserveduserinterrogationandadditionallytheITSI/GTSI/ExternalNumberoftheserveduser.4.2.2.2InvocationandoperationAllincomingcallsindicatingabasicserviceforwhichSS-CFisactiveshallbeforwardedwithoutbeingpresentedtotheserveduser(exceptedforSS-CFNRy).Oncethecallforwardinghasbeeninitiated,theoriginalcalleduserBshallnotbeabletoparticipateinthatforwardedcallregardlessofthefactthattheoriginalcondition,whichleadtotheinitiationofforwarding,disappeared(e.g.userBbusybecomesnonbusyforSS-CFB,userBNotReachablebecomesReachableforSS-CFNRc).-Thefollowingfigure1clarifiestheSS-CFprocedures.AssumethatAcallsB1,whoforwardsthecalltoB2,.,Bm,.,Bx.ThefinalreceiverofthecallisC.ABBBC1mx.Figure1:SS-CFoperation4.2.2.2.1Forwarded-touserCnotificationTheforwarded-tousershallreceiveanindicationthatthecallhasbeenforwardedwiththeappropriateforwardingcause.Accordingtotheserveduser'ssubscriptionoption,theforwarded-tousermayreceive:-theoriginalserveduser'sITSI/GTSI/ExternalNumber;-thecausefortheoriginalforwarding;-thelastforwardingnumberBx;-thecauseforthelastforwarding.Theforwardingcauseshallindicatewhichcallforwardingsupplementaryinvocationleadtotheforwarding(CFU,CFB,CFNRy,CFNRc).4.2.2.2.2CallinguserAnotificationThecallingusershallreceiveanotificationthatthecallhasbeenforwarded.Forsingleforwarding,anotificationshallbesenttothecallinguserindicatingthatcallhasbeenforwarded.SIST ETS 300 392-10-4 E2:2003

Page18ETS300392-10-4:February2000Formultipleforwarding,notificationsshallbesenttothecallinguserdependingonthesubscriptionoptionsoftheservedusersasfollows:-anotificationshallbesenttoUserAasaresultoftheforwardingatuserB1.ForwardingatsuccessiveservedusersB2,B3,etc.eachshallalsoresultinanotificationtoUserA,butonlyifboth:-thealertingstatehasbeenreachedattheserveduser;and-noneoftheservedusershasthe"No"option(inthecaseofinterworking).TheITSI/GTSI/ExternalNumberofUserCshallbesenttoUserA,butonlyifSS-COLRisnotinvokedbyUserC.NOTE1:EachuserB1,B2,…,Bn-1,Bnarefirstforwarded-touserswhobecomesuccessivelyserveduserswiththeirownsubscriptionoptions.NOTE2:Thisdoesnotapplytoeitherdirectsignalingoperationortogroupcall.NOTE3:UserAMS/LSmayreceiveanD-ALERTwithoneorigin(userBalerting)followedbyaD-CONNECTfromadifferentsource(C).4.2.3Exceptionalprocedures4.2.3.1Activation/DeactivationSS-CFforallbasicservicesandSS-CFforparticularbasicservicescannotbeactivatedsimultaneously.IftheSwMIcannotacceptanactivationrequest,theactivating(authorized/served)usershallreceiveanotificationthatSS-CFactivationwasunsuccessful.Possiblecausesforrejectionaree.g.:-serviceoroptionnotsubscribedto;-authorizedusernotenabledforactivationofSS-CF;-insufficientinformation;-forwarded-toITSI/GTSI/ExternalNumberisaspecialservicecode;-forwarded-toITSI/GTSI/ExternalNumberistheserveduser'sITSI/GTSI/ExternalNumber;-forwarded-toITSI/GTSI/ExternalNumberisaninvalidITSI/GTSI/ExternalNumber;-basicservicetowhichrelevanceisrequestedisnotsubscribedto;-incorrectserveduser'sITSI/GTSI/ExternalNumber;-conflictingsituationwithothersupplementaryservices(e.g.SS-BOC).IftheSwMIcannotacceptadeactivationrequest,thedeactivating(authorized/served)usershallreceiveanotificationthatSS-CFdeactivationwasunsuccessful.Possiblecausesforrejectionaree.g.:-serviceoroptionnotsubscribedto;-insufficientinformation;-servicenotactivated;-incorrectserveduser'sITSI/GTSI/ExternalNumber.IfthenetworkdeactivatesSS-CFwithouttheserveduserhavingrequesteddeactivation(e.g.whenanexceptionalconditionoccurs),theserveduserwillreceivenotificationalongwiththecause.Thenotificationofanunsuccessfulactivation/deactivationrequestshallbesenttotheactivating/deactivating(authorized/served)useronly.4.2.3.2InterrogationIftheSwMIcannotacceptaninterrogationrequest,theinterrogatingusershallreceiveanotificationthatSS-CFinterrogationwasunsuccessful.Possiblecausesforrejectionaree.g.:-serviceoroptionnotsubscribedto;-insufficientinformation;-basicservicetowhichrelevanceisrequestedisnotsubscribedto.SIST ETS 300 392-10-4 E2:2003

Page19ETS300392-10-4:February20004.2.3.3InvocationandoperationSS-CFshallnotbeinvokedonacalltotheserveduserifthecallusesabasicserviceforwhichSS-CFhasnotbeenactivated.Incaseswhereacallingusernormallyreceives,aspartofnotification,theITSI/GTSI/ExternalNumberoftheforwarded-touser,thelastforwardinguserortheoriginalcalleduserandthisITSI/GTSI/ExternalNumberisunavailable(e.g.duetonumberpresentationrestriction,orinter-working),theuserwhowouldhavebeengiventhenumbershallreceiveanindicationofthereasonwhynonumberisgiven.WithinaSwMIthetotalnumberofallforwardingforeachcallshallbelimited.Themaximumnumberofsuchforwardingforeachcallshallbeanimplementationoption.Whencountingthenumberofforwarding,alltypesofforwardingshallbeincluded.Ifthelimitisreachedandanattemptismadetoforwardthecallanadditionaltime,thecallingusershallrece
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