ETSI ETS 300 392-3-1 ed.1 (1999-01)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Prizemni snopovni radio (TETRA) - Govor in podatki (V+D) - 3. del: Medsebojno delovanje na medsistemskem vmesniku (ISI) - 1. poddel: Splošna zasnovaTerrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 1: General design33.070.10Prizemni snopovni radio (TETRA)Terrestrial Trunked Radio (TETRA)ICS:Ta slovenski standard je istoveten z:ETS 300 392-3-1 Edition 1SIST ETS 300 392-3-1 E1:2003en01-december-2003SIST ETS 300 392-3-1 E1:2003SLOVENSKI
STANDARD
EUROPEANETS 300 392-3-1TELECOMMUNICATIONJanuary 1999STANDARDSource: TETRAReference: DE/TETRA-03001-03-1ICS:33.020Key words:TETRA, V+DTerrestrial Trunked Radio (TETRA);Voice plus Data (V + D);Part 3: Interworking at the Inter-System Interface (ISI);Sub-part 1: General designETSIEuropean Telecommunications Standards InstituteETSI SecretariatPostal address: F-06921 Sophia Antipolis CEDEX - FRANCEOffice address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCEInternet: secretariat@etsi.fr - http://www.etsi.orgTel.: +33 4 92 94 42 00 - Fax: +33 4 93 65 47 16Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and theforegoing restriction extend to reproduction in all media.© European Telecommunications Standards Institute 1999. All rights reserved.SIST ETS 300 392-3-1 E1:2003

Page 2ETS 300 392-3-1: January 1999Whilst every care has been taken in the preparation and publication of this document, errors in content,typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to"ETSI Standards Making Support Dept." at the address shown on the title page.SIST ETS 300 392-3-1 E1:2003

Page 3ETS 300 392-3-1: January 1999ContentsForeword.51Scope.72Normative references.83Definitions and abbreviations.93.1Definitions.93.2Abbreviations.104ISI standardization methodology.114.13 stage methodology.114.1.1Stage 1.114.1.2Stage 2.124.1.3Stage 3.124.2Usage of Specification and Description Language (SDL).125Usage of Private Signalling System 1 (PSS1) for TETRA.125.1PSS1 functionality.125.2Protocol stack.135.3Generic Functional Protocol (GFP).136TETRA SwMI roles using ISI.146.1Management configurations.146.1.1Migration and group attachment configurations.146.1.1.1SwMI roles for migration and group attachment.146.1.1.2SwMI databases.146.1.1.3Migration scenarios.156.1.1.4Group attachment scenarios.166.1.2Group linking configurations.166.2Call configurations.186.2.1Group call configuration.186.2.2Individual call configuration.196.2.3Transit.206.2.4User information encoding at the ISI.207Introduction to ISI ANFs.217.1ANF-ISIMM.217.2ANF ISIIC.217.3ANF-ISIGC.217.4ANF-ISISDS.217.5ANF-ISISS.228ISI Generic Functional Protocol (ISI GFP).228.1Protocol model.228.2Services provided by the protocol model entities.238.3Addressing and routeing.248.3.1Addressing.248.3.2Routeing of ROSE APDUs.258.3.2.1Call related ROSE APDUs.258.3.2.2Call unrelated ROSE APDUs.258.3.2.2.1Establishment of a call independentsignalling connection.258.3.2.2.2Use of a call independent signallingconnection already established.278.4Remote Operations Service Entity (ROSE) requirements and operation definition.28SIST ETS 300 392-3-1 E1:2003

Page 4ETS 300 392-3-1: January 19998.4.1General.288.4.2Return-result.328.4.3Return-error.328.4.4Reject.338.5Segmentation Service Entity (SSE).338.5.1Procedures.348.5.1.1Requirements for the segmentation procedure.348.5.1.2Requirements for the re-assembly procedure.348.5.2Segment encoding.358.6Co-ordination function.369Security over the ISI.369.1ITSI authentication.369.2End-to-end encryption.379.3End-to-end key management via ISI.37Annex A (normative):Security - supporting encryption over ISI.38A.1Overview.38A.2Encryption.39A.2.1ISI relation to air interface and end-to-end encryption.39A.2.2Air interface encryption key management via ISI.39A.2.2.1Secret Key of individual subscriber (K).40A.2.2.2Derived Cipher Key (DCK).40A.2.2.3Common Cipher Key (CCK).40A.2.2.4Static Cipher Key (SCK).40A.2.2.5Group Cipher Key (GCK).40Annex B (informative):Maximum length of a ROSE APDU or a SSE segment encoded in a facilityinformation element.41B.1Call unrelated PSS1 FACILITY message.41B.2Call related PSS1 FACILITY message.42B.3ANF-ISIIC PSS1 basic call message.42History.44SIST ETS 300 392-3-1 E1:2003

Page 5ETS 300 392-3-1: January 1999ForewordThis European Telecommunication Standard (ETS) has been produced by the Terrestrial Trunked Radio(TETRA) Technical Committee of the European Telecommunications Standards Institute (ETSI).This ETS consists of 14 parts as follows:Part 1:"General network design";Part 2:"Air Interface (AI)";Part 3:"Interworking at the Inter-System Interface (ISI)";Part 4:"Gateways basic operation";Part 5:"Peripheral Equipment Interface (PEI)";Part 6:"Line connected Station (LS)";Part 7:"Security";Part 9:"General requirements for supplementary services";Part 10:"Supplementary services stage 1";Part 11:"Supplementary services stage 2";Part 12:"Supplementary services stage 3";Part 13:"SDL model of the Air Interface (AI)";Part 14:"Protocol Implementation Conformance Statement (PICS) proforma specification".Transposition datesDate of adoption of this ETS:18 December 1998Date of latest announcement of this ETS (doa):31 March 1999Date of latest publication of new National Standardor endorsement of this ETS (dop/e):30 September 1999Date of withdrawal of any conflicting National Standard (dow):30 September 1999SIST ETS 300 392-3-1 E1:2003

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Page 7ETS 300 392-3-1: January 19991ScopeThis ETS defines the Terrestrial Trunked Radio (TETRA) system supporting Voice plus Data (V+D). Itspecifies:-general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);-the system bearer and mobility management services, and the corresponding air interfaceprotocols;-the inter-working between TETRA networks;-the inter-working of TETRA networks with other networks, via gateways;-the peripheral equipment interface on the mobile station;-the Line Station (LS) interface with TETRA networks;-the security protocols and mechanisms applicable to TETRA networks and to TETRA terminalequipment;-the supplementary services applicable to the basic TETRA tele- or bearer services.This part defines the inter-working between TETRA networks over the corresponding interface, theInter-System Interface (ISI). It comprises the following sub-parts:-ISI general design;-Additional Network Feature - ISI Mobility Management (ANF-ISIMM);-Additional Network Feature - ISI Individual Call (ANF-ISIIC);-Additional Network Feature - ISI Group Call (ANF-ISIGC);-Additional Network Feature - ISI Short Data service (ANF-ISISD);-8 kbit/s encoding of user information at the ISI.This sub-part contains the ISI General Design sub-part.It specifies the general concepts which are the basis of the ISI operation between TETRA systems. Itintroduces the Additional Network Features (ANFs) used at the ISI, and specifies:-the general protocol mechanism, called ISI Generic Functional Protocol (ISI GFP), upon which thedefinition of each ANF is based; and-the security requirements for the ISI.The ISI GFP specification applies to any TETRA Switching and Management Infrastructure (SwMI) whichsupports the ISI. The security requirements for the ISI only apply to SwMIs which support authentication orencryption over the ISI.SIST ETS 300 392-3-1 E1:2003

Page 8ETS 300 392-3-1: January 19992Normative referencesThis European Telecommunication Standard (ETS) incorporates, by dated or undated reference,provisions from other publications. These references are cited at the appropriate places in the text and thepublications are listed hereafter. For dated references, subsequent amendments to or revisions of any ofthese publications apply to this European Telecommunication Standard only when incorporated in it byamendment or revision. For undated references the latest edition of the publication referred to applies.[1]CCITT Recommendation I.130 (1988): "Method for the characterization oftelecommunication services supported by an ISDN and network capabilities ofan ISDN".[2]CCITT Recommendation I.460 (1988): "Multiplexing, rate adaption and supportof existing interfaces".[3]CCITT Recommendation X.209 (1988): "Specification of basic encoding rulesfor Abstract Syntax Notation One (ASN.1)".[4]CCITT Recommendation X.219 (1988): "Remote operations: Model, notationand service definition".[5]CCITT Recommendation X.229 (1988): "Remote operations: Protocolspecification".[6]ITU-T Recommendation Z.100 (1993): "CCITT specification and descriptionlanguage (SDL)".[7]ETS 300 392-1: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);Part 1: General network design".[8]ETS 300 392-2: "Terrestrial Trunked Radio; Voice plus Data (V+D); Part 2: AirInterface (AI)".[9]ETS 300 392-7: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);Part 7: Security".[10]ETS 300 392-9: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);General requirements for supplementary services".[11]ETS 300 395-1: "Terrestrial Trunked Radio (TETRA); Speech CODEC for full-rate traffic channel; Part 1: General description of speech functions".[12]ETS 300 402-1: "Integrated Services Digital Network (ISDN); Digital SubscriberSignalling System No. one (DSS1) protocol; Data link layer; Part 1: Generalaspects [ITU-T Recommendation Q.920 (1993), modified]".[13]ETS 300 402-2: "Integrated Services Digital Network (ISDN); Digital SubscriberSignalling System No. one (DSS1) protocol; Data link layer; Part 2: Generalprotocol specification [ITU-T Recommendation Q.921 (1993), modified]".[14]ISO/IEC 11572 (1997): "Information technology - Telecommunications andinformation exchange between systems - Private Integrated Services Network -Circuit mode bearer services - Inter-exchange signalling procedures andprotocol".[15]ISO/IEC 11582 (1995): "Information technology - Telecommunications andinformation exchange between systems - Private Integrated Services Network -Generic functional protocol for the support of supplementary services - Inter-exchange signalling procedures and protocol".SIST ETS 300 392-3-1 E1:2003

Page 9ETS 300 392-3-1: January 19993Definitions and abbreviations3.1DefinitionsFor the purposes of this ETS, the following definitions apply:call: The instance of the use of a bearer or tele-service.Group TETRA Subscriber Identity (GTSI): A TETRA Subscriber Identity assigned to a group.Location Area (LA): The area within radio coverage of a base station or group of base stations withinwhich a Mobile Station (MS) is allowed to operate.Mobile Network Identity (MNI): The identity that is broadcast by all TETRA base stations to uniquelyidentify the SwMI. It consists of the Mobile Country Code (MNC) and the Mobile Network Code (MNC).Mobile Station (MS): A physical grouping that contains all of the mobile equipment that is used to obtainTETRA services. By definition, a mobile station contains at least one Mobile Radio Stack (MRS).segmentation: The act of generating two or more PDUs derived from an initial one.service user: An abstract representation of the totality of those entities in a single system that make useof a service through a single access point.supplementary service: A supplementary service modifies or supplements a basic bearer service or abasic teleservice. A supplementary service cannot be offered to a customer as a stand-alone service. Itshould be offered in combination with a bearer service or a teleservice.Switching and Management Infrastructure (SwMI): All of the TETRA equipment for a Voice plus Data(V+D) network. The SwMI enables users to communicate with each other via the SwMI.Short Subscriber Identity (SSI): The network specific portion of a TSI. A SSI is only unique within oneTETRA sub-domain (one TETRA network).TETRA Subscriber Identity (TSI): A global TETRA network address that is to identify an individual or agroup subscriber within the domain of all TETRA networks. A valid TSI refers to a TSI that has beenallocated by the network where it is being used.subscriber: A user of a telecommunication service, based on a contract with the provider of the service.The subscriber is identified by an ITSI or GTSI.NOTE 1:The subscriber is able to access the SwMI either through a MS or Line Station.user: An entity using the services of a telecommunications network via an externally accessible serviceaccess point.NOTE 2:A user may be a person or an application process.SIST ETS 300 392-3-1 E1:2003

Page 10ETS 300 392-3-1: January 19993.2AbbreviationsFor the purposes of this ETS, the following abbreviations apply:ACAuthentication CentreACSEAssociated Control Service ElementANFAdditional Network FeatureANF-ISIall Additional Network Features of the Inter-System InterfaceAPDUApplication Protocol Data UnitASN.1Abstract Syntax Notation OneBSBase StationCconditionalCCKCommon Cipher KeyC-LDBControlling Linking DataBaseCMCECircuit Mode Control EntityDCKDerived Cipher KeyECMAEuropean Computer Manufacturers AssociationGFPGeneric Functional ProtocolGFTGeneric Functional TransportGTSIGroup TETRA Subscriber IdentityGCKGroup Cipher KeyG-HDBGroup Home DataBaseG-VDBGroup Visited DataBaseHACHome Authentication CentreHDBHome DataBaseISIInter-System InterfaceITSIIndividual TETRA Subscriber IdentityI-HDBIndividual Home DataBaseI-VDBIndividual Visited DataBaseKauthentication KeyLALocation AreaLSLine StationMmandatoryMCCMobile Country CodeMMMobility ManagementMNCMobile Network CodeMNIMobile Network IdentityMRSMobile Radio StackMSMobile StationNFENetwork Facility ExtensionOoptionalOTAROver The Air Re-keyingPCProtocol ControlPDUProtocol Data UnitPINXPrivate Integrated Network eXchangePISNPrivate Integrated Services NetworkP-LBDParticipating Linking DataBasePSS1Private Signalling System 1ROSERemote Operation Service ElementRSRandom SeedSAPService Access pointSCKStatic Cipher KeySDLSpecification and Description LanguageSDShort DataSSESegmentation Service ElementSSIShort Subscriber IdentitySwMITETRA Switching and Management InfrastructureTETRATErrestrial Trunked RadioTSITETRA Subscriber IdentityVACVisitor Authentication Centre(V)ASSIVisiting Short Subscriber Alias IdentitySIST ETS 300 392-3-1 E1:2003

Page 11ETS 300 392-3-1: January 1999V+DVoice plus DataVDBVisitor DataBase(V)GSSIVisiting Short Subscriber Group Identity4ISI standardization methodology4.13 stage methodologyThe ISI Additional Network Features (ANFs) are standardized using the modelling method defined inCCITT Recommendation I.130 [1].4.1.1Stage 1Stage 1 is a description of the services which the standardized ANF entity provides to the concernedservice users, e.g. SwMI entities in the case of TETRA. The services are visible at the Service AccessPoints (SAPs). The stage 1 description is intended to allow an understanding of the servicesindependently from the implementation.For normal point to point services the service model is shown in figure 1.ANF EntitySAPSwMI-1userSAPSwMI-2userServiceServiceFigure 1: Service Model for Point to Point servicesSIST ETS 300 392-3-1 E1:2003

Page 12ETS 300 392-3-1: January 1999For point to multipoint services the service model is shown in figure 2.SAPSAPSAPuseruseruserSwMI-1SwMI-3SwMI-2ANF EntityServiceServiceServiceFigure 2: Service Model for Point to Multipoint services4.1.2Stage 2Stage 2 identifies the functional capabilities and the information flows needed to support the service asdescribed in stage 1.4.1.3Stage 3Stage 3 gives a precise description of the signalling protocols for the ANF services, i.e. the encoding rulesfor the information flows and the corresponding procedures.4.2Usage of Specification and Description Language (SDL)SDL defined in ITU-T Recommendation Z.100 [6] is used to identify and represent the behaviour of theconcerned ANF in providing services.5Usage of Private Signalling System 1 (PSS1) for TETRA5.1PSS1 functionalityThe TETRA ISI application is built on top of the PSS1 protocol stack for interconnecting Private IntegratedServices network eXchanges (PINXs) to form Private Integrated Services Network (PISN). The PSS1 isthe ISO term, which in ETSI, is also known as QSIG protocols developed by the European ComputerManufacturers Association (ECMA).TETRA uses the standard functionalities defined for PSS1:-signalling for the support of circuit-mode basic services (see note);-generic functional protocol (GFP) originally defined for the support of supplementary services.SIST ETS 300 392-3-1 E1:2003

Page 13ETS 300 392-3-1: January 1999NOTE:The definition of PSS1 basic call in ISO/IEC 11572 [14] is as follows:"The basic call is a single invocation of a basic service. Signalling procedures are usedfor establishing, maintaining and clearing a circuit-mode call at an interface betweentwo PINXs. These signalling procedures are defined in terms of messages exchangedover a signalling carriage mechanism connection within the signalling channel of theInter-PINX link. The result of successful basic call establishment is a connection forthe purpose of user information transfer".5.2Protocol stackFigure 3 shows how the protocols for TETRA ANF which apply at the ISI are built on top of the PSS1protocol stack. The Remote Operation Service Element (ROSE) is used to convey ANF-ISI Protocol DataUnits (PDU).For the TETRA ANF-ISIIC and ANF-ISIGC protocols, figure 3 has to be supplemented with a directinterface to PSS1 protocol control for basic call. In addition, basic call correlation shall be ensured for thedelivery of the corresponding PDUs by ANF-ISIIC and ANF-ISIGC through the protocol stack shown onfigure 3.NOTE:The PSS1 basic call protocol is defined in ISO/IEC 11572 [14].SwMI-1 ITU-T Rec. X.229 [10]SwMI-2ISO/IEC 11582 [4]ISO/IEC 11572 [3]Layer 1TETRA ANFSpecific TETRA operationSpecific TETRA operationITU-T Rec. X.229 [10]ISO/IEC 11582 [4]ISO/IEC 11572 [3]TETRA ANFLayer 1ETS 300 402-1 and 2 [13] [14] (see note)ETS 300 402-1 and 2[13] [14] (see note)NOTE:Layer 2 protocol depends on the type of the inter-connection.Figure 3: PSS1 protocol stack for TETRA5.3Generic Functional Protocol (GFP)The GFP as defined in ISO/IEC 11582 [15] shall be used for all TETRA ANFs of the ISI (ANF-ISI).ROSE operations shall be used to convey ANF-ISI information in facility information elements, asdescribed in clause 8. These facility information elements shall be included in PSS1 messages inaccordance with ISO/IEC 11582 [15]. The specification given in ISO/IEC 11582 [4], subclause 7.1.1.1,when a SwMI can send a PSS1 FACILITY message at the earliest, shall be understood as follows:-such message can be sent by a receiving SwMI after it has sent a PSS1 CALL PROCEEDINGmessage (following reception of a PSS1 SETUP message);-such message can be sent by a source SwMI after it has received one of the following PSS1messages: FACILITY, PROGRESS, ALERTING, CONNECT.SIST ETS 300 392-3-1 E1:2003

Page 14ETS 300 392-3-1: January 1999When the call independent signalling connection is used, it shall be connection oriented.NOTE:This is in line with the choice made for the definition of all existing supplementaryservices of the PSS1 protocols.6TETRA SwMI roles using ISI6.1Management configurations6.1.1Migration and group attachment configurations6.1.1.1SwMI roles for migration and group attachmentIn order to support the individual subscriber and group Mobility Management (MM) functionality in differentSwMIs, the following roles are defined for SwMIs:-home SwMI: The home SwMI performs the individual subscriber and group MM functions related toHome DataBase (HDB). The Mobile Network Identity (MNI) of the home SwMI shall be equal to thatof the subscriber or of the group;-visited SwMI: The visited SwMI performs the individual subscriber and group MM functions relatedto the Visitor DataBase (VDB). The MNI of the visited SwMI may or may not be equal to that of thesubscriber or of the group;-previous visited SwMI: The previous visited SwMI.6.1.1.2SwMI databasesIn order to support the individual subscriber and group MM functionality in the SwMIs, the followingdatabase functionalities are defined for the SwMIs:-the HDB comprises information about the individual and/or group subscribers. It is located in thesubscriber's home SwMI. The HDB is divided into Individual HDB (I-HDB) and Group HDB(G-HDB):-I-HDB contains the location tracking amongst SwMIs, i.e. in which SwMI is an individualsubscriber currently located. In addition, the I-HDB is able to provide the basic and optionallythe supplementary service migration profiles of the individual subscriber at migration;-G-HDB contains the group attachment tracking amongst SwMIs, i.e. in which SwMI(s)subscribers are attached to the group. In addition, the G-HDB is able to generate the basicand optionally the supplementary service migration profiles of the group subscriber at groupattachment;-the VDB comprises temporary information about individual and/or group subscribers. It is located inthe visited SwMI. The VDB is divided into Individual VDB (I-VDB) and Group VDB (G-VDB):-I-VDB contains the Individual TETRA Subscriber Identity (ITSI) and Visiting Short SubscriberAlias Identity ((V)ASSI) association and the location tracking for the individual subscriberwithin the SwMI. In addition, the I-VDB is able to provide the basic and optionally thesupplementary service migration profiles of the migrated individual subscriber;-G-VDB contains the Group TETRA Subscriber Identity (GTSI) and Visiting Short SubscriberGroup Identity ((V)GSSI) association and the group attachment tracking for the visited SwMI,i.e. which subscribers are attached to the group in the visited SwMI(s). In addition, the G-VDBis able to provide the basic and optionally the supplementary service migration profiles of theattached group;SIST ETS 300 392-3-1 E1:2003

Page 15ETS 300 392-3-1: January 1999-the Authentication Centre (AC) in the home SwMI, i.e. Home Authentication Centre (HAC), mayprovide the authentication and Over The Air Re-keying (OTAR) parameters for the migratedindividual subscriber. Similarly, the AC in the visited SwMI, i.e. the Visitor Authentication Centre(VAC), may contain the authentication and OTAR parameters provided by the home SwMI MM forthe migrated individual subscriber. The HAC and the VAC are used in conjunction with the securityservices as described in clause 10.NOTE:For ISI mobility configuration, the ACs (HAC and VAC) are considered as databases.6.1.1.3Migration scenariosThe migration is the act of changing to a new Location Area (LA) in a network (either with different MobileNetwork Code (MNC) and/or Mobile Country Code (MCC)) where the subscriber is not registered, i.e.does not have an I-VDB record.The migration shall take place either:-when an individual subscriber roams from one SwMI to another, i.e. from the previous visited SwMIto the visited SwMI; or-at power on, when the individual subscriber requests registration (migration) in a visited SwMI ofwhich the MNI is different from that of the subscriber.At migration, the home SwMI may or may not coincide with either the visited SwMI or with the previousvisited SwMI.NOTE:In this ETS, the term "coincide" means "to have the same MNI".Figure 4 illustrates the ISI configuration when a subscriber migrates from the previous visited SwMI to thevisited SwMI, and when the home SwMI does not coincide with either the previous visited SwMI or thevisited SwMI.previous visited SwMIvisited SwMIhome SwMIISIISIFigure 4: Migration scenario between SwMIsSIST ETS 300 392-3-1 E1:2003

Page 16ETS 300 392-3-1: January 1999At migration, the home SwMI shall update the subscriber's location information in the I-HDB to be used forthe subscriber's location tracking amongst the SwMIs.The visited SwMI shall create an I-VDB record to be used for the subscriber's location tracking within thevisited SwMI. In addition, the visited SwMI shall create the subscriber's migration profiles and save them inthe I-VDB. The migration profiles shall indicate the subscriber's service authorizations during the migrationin the visited SwMI. The visited SwMI shall also allocate the (V)ASSI for the individual subscriber asdefined in ETS 300 392-1 [7], subclause 7.2.2.If the subscriber was registered prior to the migration, the previous visited SwMI shall remove thesubscriber's information that has been created and save in the previous visited SwMI. This information ise.g. the I-VDB record and the ITSI-(V)ASSI association.A MS/LS may contain more than one TETRA Subscriber Identity (TSI) family and each of those shallmigrate independently.6.1.1.4Group attachment scenariosThe group attachment enables migrated subscribers to participate in group calls if the home SwMI of thegroup and that of the migrated subscriber coincide. As result of the group attachment, the home SwMIshall know to which SwMIs the group call shall be extended and the visited SwMI shall know to whichsubscribers the group call shall be set-up.Figure 5 illustrates the ISI configuration for the group attachment, which shall take place between thehome SwMI (of the group and of the subscriber) and the visited SwMI in which the subscriber is migrated.home SwMIISIvisited SwMIFigure 5: Group attachment scenarioWhen the group is attached for the first time in the visited SwMI, the home SwMI shall update the groupattachment to the G-HDB to be used for the group attachment tracking amongst the SwMIs.The visited SwMI shall create a G-VDB record to be used for the subscribers' group attachment trackingwithin the visited SwMI. In addition, the visited SwMI shall create the migration profiles for the group andsave them in the G-VDB. The migration profiles shall indicate the service authorizations for the group inthe visited SwMI. The visited SwMI shall also allocate the (V)GSSI for the group as defined inETS 300 392-1 [7], subclause 7.2.2.A subscriber may attach to one or more groups and each of those shall be attached independently.6.1.2Group linking configurationsThe group linking shall enable the dynamic linking, i.e. combining, of groups having different SwMIs astheir home SwMIs over the ISI. After the group linking the group calls made to any of the groups shallresult in combined group calls consisting of all the members of the linked groups. The combined groupcall is described in the ETS defining ANF-ISIGC.SIST ETS 300 392-3-1 E1:2003

Page 17ETS 300 392-3-1: January 1999In order to support the group linking functionality in different SwMIs, the following roles are defined forSwMIs:-linking controlling SwMI: The group linking controlling SwMI controls the making of the linking forthe group, i.e. group linking. In addition, the linking controlling SwMI creates the group linkingservice profile to be used for the group linking. The group linking controlling SwMI is the homeSwMI of one of the linked groups;-linking participating SwMI: The group linking participating SwMI participates the group linking inlinking (joining) one group to the group linking. The group linking participating SwMI is the homeSwMI of the linked group;-linking originating SwMI: The group linking originating SwMI originates the request to group linking.The group linking originating SwMI is either the group linking controlling SwMI or the group linkingparticipating SwMI.In addition, the following database functionalities are defined for the SwMIs supporting group linking:-Controlling Linking DataBase (C-LDB): The C-LDB contains the linking tracking for the linkedgroups, i.e. the information which groups are part of the group linking. In addition, the C-LDBcontains the linking service profile for the group linking;-Participating Linking DataBase (P-LDB): The P-LDB contains the linking tracking for one of thelinked groups, i.e. the information whether the group is linked or not. The P-LDB is located in thehome SwMI of the group.From two to several groups may be linked together using group linking. Figure 6 illustrates the ISIconfiguration for group linking when three groups are linked together.linking controlling andlinking participating SwMIISIlinking participating SwMIISIlinking originating andlinking participating SwMIFigure 6: Group linking scenarioSIST ETS 300 392-3-1 E1:2003

Page 18ETS 300 392-3-1: January 1999At group linking, the linking controlling SwMI shall co-ordinate and keep track of the group linking amongstthe linking participating SwMIs. In addition, the linking controlling SwMI shall create the linking serviceprofile for the group linking and save it to the C-LDB.Each of the linking participating SwMIs shall link a group to the group linking and create a P-LDB record tobe used for the group during the group linking.A group can be part of only one group linking at a given time.6.2Call configurationsWhether it is a group call or an individual call, a call is originated by a calling user. The SwMI where thisuser is located is called the originating SwMI. By definition, the originating SwMI is the visited SwMI of thecalling user. It may or may not be its home SwMI.The other possible roles for SwMIs in a group call and in an individual call where an ISI is involved arepresented in the following.6.2.1Group call configurationIn order to support group call processing in different SwMIs, the following roles are defined, in addition tothat of originating SwMI:-controlling SwMI: The controlling SwMI shall be in charge to set up and maintain a call extendingover two or more SwMIs or to deliver a short data service request involving more than one SwMI.The controlling SwMI shall be the group home SwMI;-participating SwMI: The participating SwMI only participates in the call without controlling it. Theparticipating SwMI shall always be the end point of the call, i.e. where the call is terminated.NOTE:Once the originating SwMI has requested the establishment of the call over the ISI tothe controlling SwMI, it does not make anymore actions.Point-to-multipoint call set-up between SwMIs shall be set-up as a logical star configuration where thecontrolling SwMI shall be the centre of the star.When a user sets up a group call, the controlling SwMI shall establish the call. This shall hold regardlessof whether the calling user is located or not in its home SwMI and regardless of whether the calling user isa member of the group or not. Some called users may be located in the controlling SwMI.Figure 7 illustrates the ISI configuration when a group call is initiated between two SwMIs, the originatingSwMI being the home SwMI of the group. The originating SwMI is then also the controlling SwMI.controlling SwMIparticipating SwMIISIoriginating andFigure 7: Group call configurationSIST ETS 300 392-3-1 E1:2003

Page 19ETS 300 392-3-1: January 1999Figure 8 illustrates the ISI configuration when the originating SwMI of a group call is not the group homeSwMI. The originating SwMI becomes then a participating SwMI.controlling SwMIparticipating SwMIISIparticipating SwMIISIoriginating andFigure 8: Group call configuration6.2.2Individual call configurationWhen a SwMI sets up an individual call an ANF-ISIIC shall be invoked to extend this call over the ISI.Figure 9 illustrates the ISI configuration when an individual call is initiated between two SwMIs.originating SwMIterminating
SwMIISIFigure 9: Individual call configurationSIST ETS 300 392-3-1 E1:2003

Page 20ETS 300 392-3-1: January 1999When a user is called, the invoked ANF-ISIIC will first route the call request in the called SwMI, thisrouteing being independent of whether or not the originating SwMI is the home SwMI of the calling user.The invoked ANF-ISIIC will then ensure the adequate routeing of the call to the terminating SwMI in thecalled SwMI. Three possible cases arise for this routeing:-the called SwMI is the called user home SwMI and this user has not migrated; or-the called SwMI is the called user home SwMI and this user has migrated; or-the called SwMI is not the called user home SwMI and this user has migrated (i.e. its home SwMI isthe originating SwMI).By definition, the originating SwMI shall be the controlling SwMI for half duplex operation.6.2.3TransitAdditionally any SwMI shall have a transit capability for the following cases:-forward switching in the case of individual call where the SwMI is the called user home SwMI andwhere the called user has migrated;-call restoration;-specific supplementary operation (e.g. call diversion).NOTE:In addition, a SwMI may act as a standard PISN transit, but this is outside the scope ofthis ETS.6.2.4User information encoding at the ISIWhether in a group call or in an individual call, the user information will be sent over ISI user informationconnections, which will be considered as BQ channels by the PSS1 protocols used to establish thesecalls.It has been assumed that these connections will be digital, their standard data rate being 64 kbit/s.The user information sent in one air interface slot shall be encoded at the ISI into an 8 Kbit/s bit stream.This encoding is defined in other parts of this ETS for both data calls (at 7,2 kbit/s, 4,8 kbit/s or 2,4 kbit/s)or speech calls. It allows to carry stolen frame signalling in-band and to identify precisely such signallingwithin the user information bit stream.As a result, calls which use N slots at the air interface, with N = 2 to 4, shall be multiplexed into N ´ 8kbit/sstreams, which would still be carried by the same 64 kbit/s BQ channel (the corresponding straightforwardmultiplexing being defined in CCITT Recommendation I.460 [2]).As an option 8 kbit/s connections could be considered for BQ channels, N slot calls being handled over theISI as PSS1 multi-rate calls, when this option will have been standardized for 8 kbit/s channels.SIST ETS 300 392-3-1 E1:2003

Page 21ETS 300 392-3-1: January 19997Introduction to ISI ANFsThe following ANFs will be defined for the ISI:-Additional Network Feature - Inter-System Interface Mobility Management (ANF-ISIMM);-Additional Network Feature - Inter-System Interface Individual Call (ANF-ISIIC);-Additional Network Feature - Inter-System Interface Group Call (ANF-ISIGC);-Additional Network Feature - Inter-System Interface Short Data Service (ANF-ISISDS);-Additional Network Feature - general requirements for Supplementary Services (SS) - seeclause 10 of ETS 300 392-9 [10].All their protocols will be designed so that their messages can be routed through transit PISNs, togetherwith the associated call for those messages which are call related.7.1ANF-ISIMMANF-ISIMM enables the TETRA air interface MM, authentication and OTAR services between SwMIssharing an ISI. In doing so, ANF-ISIMM allow the subscribers e.g. to migrate, to be authenticated, toattach to groups and, thus, to participate in individual and group calls.NOTE:The TETRA air interface MM services are defined in ETS 300 392-2 [8], clause 15,and the TETRA security authentication and the OTAR key management services inETS 300 392-7 [9], clause 4. However, ANF-ISIMM does not support the forwardregistration nor the assignment of Group Cipher key (GCK) as defined inETS 300 392-2 [8], clause 15, and in ETS 300 392-7 [9], clause 4, respectively.In addition, ANF-ISIMM offers database fault recovery services for SwMIs, in order to recover thedatabases after faulty situations, and group linking and unlinking services, in order to enable the dynamiccombining of groups to support combined group calls between SwMIs.7.2ANF ISIICANF-ISIIC enables calls to be set-up from a TETRA user registered in one SwMI to another TETRA userregistered in another SwMI, operating at the ISI of both SwMIs. It also supports call restoration when auser has migrated to another TETRA SwMI during an established call. Additionally, ANF-ISIIC allowsTETRA signalling information to be passed from a TETRA SwMI to another TETRA SwMI supporting theTETRA Individual Call procedures as defined in clauses 11 and 14 of ETS 300 392-2 [8].7.3ANF-ISIGCANF-ISIGC enables point-to-multipoint calls to be set-up between TETRA users located in more than oneTETRA SwMI, operating at the ISI of all these SwMIs. It also supports call restoration when a user hasmigrated to another TETRA SwMI during an established call. Additionally, the ANF-ISIGC shall handletransmission control signalling from all SwMIs involved in the given group call supporting the point tomultipoint TETRA call procedures defined in clauses 11 and 14 of ETS 300-392-2 [8].7.4ANF-ISISDSANF-ISISDS enables point-to-point or point-to-multipoint short data messages to be passed betweenTETRA users located in more than one TETRA SwMI, operating at the ISI of all these SwMIs.SIST ETS 300 392-3-1 E1:2003

Page 22ETS 300 392-3-1: January 19997.5ANF-ISISSANF-ISISS is a transport mechanism to allow signalling information exchange between two SwMI CircuitMode Control Entities (CMCEs), as defined in ETS 300 392-2 [8], clause 14, for the control of TETRAsupplementary services. It operates at the ISI of both SwMIs.It is used for the exchange of signalling information between peer CMCEs in the specifications ofsupplementary service protocols.8ISI Generic Functional Protocol (ISI GFP)8.1Protocol modelThe TETRA ISI is based on the PSS1 protocols stack in order to enable the interconnection of SwMIs viatransit PISNs. Signalling needs for TETRA ISI operation which are not directly supported by PSS1protocols are provided by ISI GFP.ISI GFP does not by itself control any ANF-ISI PDUs but rather provides a means to convey them.SIST ETS 300 392-3-1 E1:2003

Page 23ETS 300 392-3-1: January 1999Figure 10 shows the conceptual model of the ISI GFP and its relationship to the various ANF entities. It isderived from figure 3 of ISO/IEC 11582 [15].ROSECo-ordi-nationFunctionGFT ControlSSEANF-ISIIC/ANF-ISIGCROSE = Remote Operations Service Element;SSE
= Segmentation Service Element;GFT = Generic Functional Transport.Protocol
ControlANF-ISISDANF-ISIMMANF-ISISSNOTE:Capabilities defined in this ETS are indicated by shading, i.e. ROSE, SSE and Co-ordinationfunction.Figure 10: Protocol model of the ISI Generic Functional ProtocolThe entities Protocol Control (PC), Generic Functional Transport (GFT) control, co-ordination function andROSE shall exist in any SwMI which
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