ETSI EN 300 392-3-9 V1.4.0 (2026-03)

Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 9: Transport layer independent, General design

REN/TCCE-03276

Prizemni snopovni radio (TETRA) - Govor in podatki (V+D) - 3. del: Medsebojno delovanje na medsistemskem vmesniku (ISI) - 9. poddel: Neodvisnost transportnih plasti, splošna zasnova

General Information

• Status: Not Published
• Technical Committee: TCCE 3 - TCCE Air Interface and Network Protocols
• Current Stage: 9 - Start of OAP
• Due Date: 25-Mar-2026
• Completion Date: 25-Mar-2026
• Ref Project: oSIST prEN 300 392-3-9 V1.4.0:2026 - Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D) - Part 3: Interworking at the Inter-System Interface (ISI) - Sub-part 9: Transport layer independent, General design

Standards Content (Sample)

Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)

EUROPEAN STANDARD
Terrestrial Trunked Radio (TETRA);
Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI);
Sub-part 9: Transport layer independent, General design

2 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)

Reference
REN/TCCE-03276
Keywords
management, mobility, TETRA
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ETSI
3 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 7
1 Scope . 8
2 References . 8
2.1 Normative references . 8
2.2 Informative references . 9
3 Definition of terms, symbols and abbreviations . 10
3.1 Terms . 10
3.2 Symbols . 11
3.3 Abbreviations . 11
4 ISI standardization methodology . 12
4.1 3 stage methodology . 12
4.2 Stage Descriptions . 13
4.2.1 Stage 1 description . 13
4.2.2 Stage 2 description . 13
4.2.3 Stage 3 description . 14
4.3 Usage of Specification and Description Language (SDL) . 14
5 TETRA SwMI roles using ISI . 14
5.1 Management configurations . 14
5.1.1 Migration and group attachment configurations . 14
5.1.1.1 SwMI roles for migration and group attachment . 14
5.1.1.2 SwMI databases . 14
5.1.1.3 Migration scenarios . 15
5.1.1.4 Group attachment scenarios . 16
5.1.2 Group linking configurations . 17
5.2 Call processing . 19
5.2.1 Group call processing . 19
5.2.2 Individual call processing . 20
5.2.3 Transit . 21
6 Introduction to ISI ANFs . 21
6.1 ISI ANF Overview . 21
6.2 ANF-ISIMM. 22
6.3 ANF-ISIIC . 22
6.4 ANF-ISIGC . 22
6.5 ANF-ISISDS . 22
6.6 ANF-ISISS . 22
7 ISI Generic Functional Protocol (ISI GFP) . 22
7.1 Protocol model . 22
7.2 Services provided by the conceptual protocol model entities . 23
7.3 Addressing and transport . 24
7.4 ISI GFP requirements and operation definition . 24
7.4.1 General . 24
7.4.2 Result . 27
7.4.3 ReturnError . 27
7.4.4 Reject . 28
7.4.5 Procedures. 28
8 Security related functions the ISI . 30
8.1 Security overview . 30
8.2 ITSI authentication . 30
8.3 End-to-end encryption . 30
8.4 End-to-end key management via ISI . 31
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4 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
Annex A (normative): Security - supporting encryption over ISI . 32
A.1 Overview . 32
A.2 Encryption . 33
A.2.1 ISI relation to air interface and end-to-end encryption . 33
A.2.2 Air interface encryption key management via ISI . 33
A.2.2.1 OTAR . 33
A.2.2.2 Secret Key of individual subscriber (K or K2) . 34
A.2.2.3 Derived Cipher Key (DCK or DCKX) . 34
A.2.2.4 Common Cipher Key (CCK or CCKX) . 34
A.2.2.5 Static Cipher Key (SCK or SCKX) . 34
A.2.2.6 Group Cipher Key (GCK or GCKX) . 34
Annex B (informative): Encoding Example . 35
History . 37

ETSI
5 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
Intellectual Property Rights
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Foreword
This draft European Standard (EN) has been produced by ETSI Technical Committee TETRA and Critical
Communications Evolution (TCCE), and is now submitted for the combined Public Enquiry and Vote phase of the
ETSI EN Approval Procedure (ENAP).

Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa
Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

The present document is part 3, sub-part 9 of a multi-part deliverable covering the Terrestrial Trunked Radio (TETRA);
Voice plus Data (V+D), as identified below:
Part 1: "General network design";
Part 2: "Air Interface (AI)";
Part 3: "Interworking at the Inter-System Interface (ISI)":
Sub-part 1: "General design";
Sub-part 2: "Additional Network Feature Individual Call (ANF-ISIIC)";
Sub-part 3: "Additional Network Feature Group Call (ANF-ISIGC)";
Sub-part 4: "Additional Network Feature Short Data Service (ANF-ISISDS)";
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6 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
Sub-part 5: "Additional Network Feature for Mobility Management (ANF-ISIMM)";
Sub-part 6: "Speech format implementation for circuit mode transmission";
Sub-part 7: "Speech Format Implementation for Packet Mode Transmission";
Sub-part 8: "Generic Speech Format Implementation";
Sub-part 9: "Transport layer independent, General design";
Sub-part 10: "General design, PSS1 over E.1";
Sub-part 11: "General design, SIP/IP";
Sub-part 12: "Transport layer independent Additional Network Feature Individual Call (ANF-ISIIC)";
Sub-part 13: "Transport layer independent Additional Network Feature Group Call (ANF-ISIGC)";
Sub-part 14: "Transport layer independent Additional Network Feature Short Data Service (ANF-ISISDS)";
Sub-part 15: "Transport layer independent Additional Network Feature, Mobility Management
(ANF-ISIMM)";
Part 4: "Gateways basic operation";
Part 5: "Peripheral Equipment Interface (PEI)";
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";
Part 15: "TETRA frequency bands, duplex spacings and channel numbering";
Part 16: "Network Performance Metrics";
Part 17: "TETRA V+D and DMO specifications";
Part 18: "Air interface optimized applications";
Part 19: "Interworking between TETRA and Broadband systems".
NOTE 1: Part 3, sub-parts 6 and 7 (Speech format implementation), part 4, sub-part 3 (Data networks gateway),
part 10, sub-part 15 (Transfer of control), part 13 (SDL) and part 14 (PICS) of this multi-part deliverable
are in status "historical" and are not maintained.
NOTE 2: Some parts are also published as Technical Specifications such as ETSI TS 100 392-2 and those may be
the latest version of the document.
The present document is based on ETSI EN 300 392-3-1 [i.5]. The main differences are:
• Any transport protocol (PSS1) information is removed as several different transport protocols can be used.
• Any reference to ROSE ([i.4] and [i.5]) is removed and the necessary description of the PDU identification has
been added.
• The ASN.1 specification of the PDUs has been re-designed taking into account that the reference to ROSE is
removed.
ETSI
7 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
For all sub-parts in the TETRA specification ETSI EN 300 392-3 "Interworking at the Inter-System Interface (ISI)" [3],
[4], [5], [6], [7], [8] and [9] the terms ISI and TETRA ISI are equivalent.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI
8 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
1 Scope
The present document defines the general aspects of interworking at the Inter-System Interface (ISI) for Terrestrial
Trunked Radio (TETRA) system supporting Voice plus Data (V+D). Those specify the general concepts which are the
basis of the ISI operation between TETRA systems. It introduces the Additional Network Features (ANFs) used at
the ISI, and specifies:
• the general protocol mechanism upon which the definition of each ANF is based; and
• the security related functions over the ISI.
The specification of the general transport layer independent protocol mechanism applies to any TETRA Switching and
Management Infrastructure (SwMI) which supports the ISI. The security requirements for the ISI only apply to SwMIs
which support authentication or end-to-end encryption over the ISI.
Besides the ISI general design, the present sub-part, interworking at the Inter-System Interface comprises the following
other sub-parts:
• General design, PSS1 over E.1 [3];
• General design, SIP/IP [4];
• Transport layer independent Additional Network Feature Individual Call (ANF-ISIIC) [5];
• Transport layer independent Additional Network Feature Group Call (ANF-ISIGC) [6];
• Transport layer independent Additional Network Feature Short Data Service (ANF-ISISDS) [7];
• Transport layer independent Additional Network Feature, Mobility Management (ANF-ISIMM) [8]; and
• Generic Speech Format Implementation [9].
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found in the
ETSI docbox.
NOTE 1: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long-term validity.
NOTE 2: Note that for the TETRA standards, the reference is always to a European Standard (ETSI EN 300 xxx) if
such has been published, but the latest version of that standard can be either an EN or a Technical
Specification (ETSI TS 100 xxx), even if this is not visible in the reference list.
The following referenced documents are necessary for the application of the present document.
[1] ETSI EN 300 392-1: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 1: General network design".
[2] ETSI EN 300 392-2: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 2: Air Interface (AI)".
[3] ETSI EN 300 392-3-10: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 10: General design, PSS1
over E.1".
ETSI
9 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
[4] ETSI EN 300 392-3-11: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 11: General design, SIP/IP".
[5] ETSI EN 300 392-3-12: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 12: Transport Layer Independent
Additional Network Feature Individual Call (ANF-ISIIC)".
[6] ETSI EN 300 392-3-13: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 13: Transport layer independent
Additional Network Feature Group Call (ANF-ISIGC)".
[7] ETSI EN 300 392-3-14: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 14: Transport Layer Independent
Additional Network Feature Short Data Service (ANF-ISISDS)".
[8] ETSI EN 300 392-3-15: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 15: Transport layer independent
Additional Network Feature, Mobility Management (ANF-ISIMM)".
[9] ETSI EN 300 392-3-8: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 8: Generic Speech Format
Implementation".
[10] ETSI EN 302 109: "Terrestrial Trunked Radio (TETRA); Security; Synchronization mechanism
for end-to-end encryption".
[11] ETSI EN 300 392-9: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 9: General requirements for supplementary services".
[12] Recommendation ITU-T X.690: "Information technology - ASN.1 encoding rules: Specification of
Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding
Rules (DER)".
[13] ETSI EN 300 392-7: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 7: Security".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE 1: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long-term validity.
NOTE 2: Note that for the TETRA standards, the reference is always to a European Standard (ETSI EN 300 xxx) if
such has been published, but the latest version of that standard can be either an EN or a Technical
Specification (ETSI TS 100 xxx), even if this is not visible in the reference list.
The following referenced documents may be useful in implementing an ETSI deliverable or add to the reader's
understanding, but are not required for conformance to the present document.
[i.1] ETSI EN 300 395-1: "Terrestrial Trunked Radio (TETRA); Speech CODEC for full-rate traffic
channel; Part 1: General description of speech functions".
[i.2] Recommendation ITU-T I.130: "Method for the characterization of telecommunication services
supported by an ISDN and network capabilities of an ISDN".
[i.3] Recommendation ITU-T Z.100: "Specification and description language (SDL)".
[i.4] Recommendation ITU-T X.219: "Remote Operations: Model, notation and service definition".
ETSI
10 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
[i.5] ETSI EN 300 392-3-1: "Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D);
Part 3: Interworking at the Inter-System Interface (ISI); Sub-part 1: General design".
NOTE: ETSI EN 300 392-3-1 is in status "historical" and is not maintained.
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
call independent: property of information which is conveyed between SwMI on a signalling connection which is not
related to an audio call
call independent signalling connection: signalling connection established between ANF-ISI entities located in
different Switching and Management Infrastructures that is not related to audio calls
destination SwMI: Switching and Management Infrastructure where the receiving ANF-ISI entity is located (in the
context of a single one-way exchange of information between two ANF-ISI entities located in different Switching and
Management Infrastructures)
Group TETRA Subscriber Identity (GTSI): TETRA Subscriber Identity assigned to a group
home SwMI: home of the MS's ITSI, i.e. the SwMI where the network code (MNC) is equal to that of the individual
subscriber (ITSI)
invocation: action taken by the user or by the service provider to execute a specific service function within real time
ISI mediation function: entity which provides to different ANF-ISI entities the services that are not supported by the
transport layer protocol
Location Area (LA): area within radio coverage of a base station or group of base stations within which a Mobile
Station (MS) is allowed to operate
Mobile Network Identity (MNI): identity that identify the SwMI
NOTE: It consists of the Mobile Country Code (MCC) and the Mobile Network Code (MNC).
Mobile Station (MS): physical grouping that contains all of the mobile equipment that is used to obtain TETRA
services
NOTE: By definition, a mobile station contains at least one Mobile Radio Stack (MRS).
originating SwMI: in the context of a TETRA call, Switching and Management Infrastructure where the calling user is
registered (which implies that this user is located in that SwMI) or Switching and Management Infrastructure which
originates a Call independent signalling connection
segmentation: act of generating two or more transport layer PDUs derived from one initial ISI PSU
service user: abstract representation of the totality of those entities in a single system that makes use of a service
through a single access point
Short Subscriber Identity (SSI): network specific portion of a TSI
NOTE: A SSI is only unique within one TETRA sub-domain (one TETRA network).
source SwMI: switching and management infrastructure where the sending ANF-ISI entity is located (in the context of
a single one-way exchange of information between two ANF-ISI entities located in different Switching and
Management Infrastructures)
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11 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
subscriber: user of a telecommunication service, based on a contract with the provider of the service
NOTE 1: The subscriber may be an individual or a group: in the first case it is identified by an ITSI, in the second,
by a GTSI.
NOTE 2: The individual subscriber is able to access an SwMI either through a MS or Line Station.
supplementary service: service which modifies or supplements a basic bearer service or a basic teleservice
NOTE: A supplementary service cannot be offered to a customer as a stand-alone service. It should 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
terminating SwMI: in the context of a TETRA call, Switching and Management Infrastructure where the called user is
registered (which implies that this user is located in that SwMI) or Switching and Management Infrastructure which
terminates a Call independent signalling connection
TETRA Subscriber Identity (TSI): global TETRA network address that is to identify an individual or a group
subscriber within the domain of all TETRA networks
user: entity using the services of a telecommunications network via an externally accessible service access point
NOTE: An individual user may be a person or an application process.
visited SwMI: TETRA network which MNI is not equal to the user's MNI
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Authentication Centre
AI Air Interface
ANF Additional Network Feature
ANF-ISI all Additional Network Features of the Inter-System Interface
APDU Application Protocol Data Unit
ASN.1 Abstract Syntax Notation One
ASSI Alias Short Subscriber Identity
BER Basic Encoding Rules
BS Base Station
C Conditional
CAD Call Authorized by Dispatcher
CCK Common Cipher Key
CCKX Extended Common Cipher Key
C-LDB Controlling Linking DataBase
CLIR Calling Line Identification Restriction
DCK Derived Cipher Key
DCKX Extended Derived Cipher Key
DMO Direct Mode Operation
GCK Group Cipher Key
GCKX eXtended Group Cipher Key
GFP Generic Functional Protocol
G-HDB Group Home DataBase
GSSI Group Short Subscriber Identity
GTSI Group TETRA Subscriber Identity
G-VDB Group Visited DataBase
HAC Home Authentication Centre
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12 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
HDB Home DataBase
I-HDB Individual Home DataBase
IP Internet Protocol
ISI Inter-System Interface
ISIGC Inter-System Interface Group Call
ISIIC Inter-System Interface Individual Call
ISIMM Inter-System Interface Mobility Management
ISISDS Inter-System Interface Short Data Service
ISISS Inter-System Interface Supplementary Services
ITSI Individual TETRA Subscriber Identity
ITU-T International Telecommunication Union - sector Telecommunication Standardization Sector
I-VDB Individual Visited DataBase
K authentication Key
K2 authentication Key
KS Key Seed
LA Location Area
LDB Linking DataBase
LS Line Station
M Mandatory
MCC Mobile Country Code
MM Mobility Management
MNC Mobile Network Code
MNI Mobile Network Identity
MRS Mobile Radio Stack
MS Mobile Station
O Optional
OTAR Over The Air Re-keying
PDU Protocol Data Unit
PEI Peripheral Equipment Interface
PICS Protocol Implementation Conformance Statement
P-LDB Participating Linking DataBase
ROSE Remote Operation Service Element
RS Random Seed
SAP Service Access Point
SCK Static Cipher Key
SCKX Extended Static Cipher Key
SDL Specification and Description Language
SDS Short Data Service
SIP Session Initiation Protocol
SS Supplementary Service
SSI Short Subscriber Identity
SwMI TETRA Switching and Management Infrastructure
TETRA TErrestrial Trunked RAdio
TSI TETRA Subscriber Identity
(V)ASSI Visiting Alias Short Subscriber Identity
(V)GSSI Visiting Group Short Subscriber Identity
V+D Voice plus Data
VAC Visitor Authentication Centre
VDB Visitor DataBase
4 ISI standardization methodology
4.1 3 stage methodology
The ISI Additional Network Features (ANFs), listed in clause 7, are standardized using the modelling method defined in
Recommendation ITU-T I.130 [i.2].
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13 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
4.2 Stage Descriptions
4.2.1 Stage 1 description
Stage 1 description defines the services which the standardized ANF entity provides to the concerned service users,
e.g. SwMI entities in the case of TETRA. The services are visible at the Service Access Points (SAPs). The stage 1
description is intended to allow an understanding of the services independently from the implementation.
For normal point to point services the service model is shown in figure 4.1.
Service Service
user user
SwMI-1
SwMI-2
SAP
SAP
ANF Entity
Figure 4.1: Service model for point to point services
Point to point services may span several SwMIs in a raw with each their Service user.
For point-to-multipoint services the service model is shown in figure 4.2.
Service
Service
user
user
SwMI-1 SwMI-2
SAP SAP
ANF Entity
SAP
SwMI-3
Service
user
Figure 4.2: Service model for point-to-multipoint services
Point-to-multipoint services may span 2 or more SwMIs where one of the SwMIs is communicating with all the other
SwMIs and the other SwMIs are not aware of each other, e.g. in a group call the controlling SwMI communicates with
all participating SwMIs but the participating SwMIs are only communicate with the controlling SwMI.
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14 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
4.2.2 Stage 2 description
Stage 2 description identifies the functional capabilities and the information flows needed to support the service as
described in stage 1.
4.2.3 Stage 3 description
Stage 3 description gives a precise specification of the signalling protocols for the ANF services, i.e. the encoding rules
for the information flows and the corresponding procedures.
4.3 Usage of Specification and Description Language (SDL)
SDL defined in Recommendation ITU-T Z.100 [i.3] is used to identify and represent the behaviour of the concerned
ANF in providing services.
5 TETRA SwMI roles using ISI
5.1 Management configurations
5.1.1 Migration and group attachment configurations
5.1.1.1 SwMI roles for migration and group attachment
In order to support the Mobility Management (MM) functionality in different SwMIs for a given subscriber (whether
individual subscriber or group), the following SwMI roles are defined:
• individual subscriber home SwMI: The Mobile Network Identity (MNI) of the individual subscriber home
SwMI shall be equal to the extended part of the TSI of the subscriber;
• individual subscriber visited SwMI: The Mobile Network Identity (MNI) of the individual subscriber visited
SwMI is different from the extended part of the TSI of that subscriber (since this SwMI is different from the
individual subscriber home SwMI;
• group home SwMI: The Mobile Network Identity (MNI) of the group home SwMI shall be equal to the
extended part of the TSI of the group;
• group visited SwMI: The Mobile Network Identity (MNI) of the group visited SwMI shall be different from
the extended part of the TSI of the group.
5.1.1.2 SwMI databases
In order to support the individual subscriber and group MM functionality in the SwMIs, the following databases are
defined:
• the HDB comprises information about the individual and/or group subscribers. It is located in the subscriber'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 individual subscriber
currently located. In addition, the I-HDB is able to provide the basic and optionally the supplementary
service migration profiles of the individual subscriber at migration;
- G-HDB contains the group attachment tracking amongst SwMIs, i.e. which SwMIs are group attached.
In addition, the G-HDB is able to provide the basic and optionally the supplementary service migration
profiles of the group (subscriber) at group attachment;
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15 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
• the VDB comprises temporary information about individual and/or group subscribers. For a given individual
subscriber member of one or more groups, it is located in the SwMI where that subscriber is registered (be it
his home SwMI or a 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 Subscriber Alias
Identity ((V)ASSI) association (if the individual subscriber is located in a visited SwMI) and the location
tracking for the individual subscriber within the SwMI. In addition, the I-VDB is able to provide the
basic and optionally the supplementary service profiles of the individual subscriber;
- G-VDB contains the Group TETRA Subscriber Identity (GTSI) and Visiting Short Subscriber Group
Identity ((V)GSSI) association (if located in a group visited SwMI) and the identities of the individual
subscribers attached to the group in the SwMI. In addition, the G-VDB is able to provide the basic and
optionally the supplementary service migration profiles of the attached group;
• the Authentication Centre (AC) in the home SwMI, i.e. Home Authentication Centre (HAC), may provide the
authentication and Over The Air Re-keying (OTAR) parameters for the migrating individual 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 for the migrating individual
subscriber. The HAC and the VAC are used in conjunction with the security services as described in clause 8.
NOTE: For ISI mobility configuration, the ACs (HAC and VAC) are considered as databases.
5.1.1.3 Migration scenarios
The migration is the act for an individual subscriber of moving from a Location Area (LA) in the network where that
subscriber is currently registered (i.e. does have an I-VDB record) to a new LA in another network (either with different
Mobile Network Code (MNC) and/or Mobile Country Code (MCC)) - where that subscriber is not registered.
Such migration from the ANF-ISI point of view shall take place:
• when an individual subscriber moves from one SwMI to another, i.e. from the SwMI where it was previously
registered to a new one (be it his home SwMI or a visited SwMI);
• at power on, when the individual subscriber requests registration (migration) in a SwMI different from his
home SwMI; or
• at power on, when the individual subscriber requests registration in the home SwMI and was registered at
power off in another SwMI.
NOTE: From the mobile station point of view a registration is always required at power on; therefore the mobile
station need not remember where it was registered at power off.
Figure 5.1 illustrates the ISI configuration when an individual subscriber migrates from a previous visited SwMI to new
one.
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16 Draft ETSI EN 300 392-3-9 V1.4.0 (2026-03)
ISI ISI
home SwMI
previous visited SwMI
visited SwMI
Figure 5.1: Migration scenario between SwMIs
At migration, the home SwMI shall update the individual subscriber's location information in the I-HDB.
The SwMI in which the migrating user has just registered (whether that SwMI is a visited SwMI or his home SwMI - in
the latter case this means that the user has just migrated back into his home SwMI) shall create an I-VDB record to be
used for the subscriber's location tracking within this SwMI. In addition, if that SwMI is different from the user home
SwMI (i.e. it is the user visited SwMI), it shall fetch the subscriber's migration profiles (sent through ANF-ISIMM else
defined by default) and save them in the I-VDB.
The migration profiles shall indicate the subscriber's service authorizations during the migration in the visited SwMI.
The visited SwMI shall also allocate the (V)ASSI for the individual subscriber as defined in clause 7.2.2 of ETSI
EN 300 392-1 [1].
As part of the migration procedure (after the individual subscriber has been successfully registered in the SwMI into
which it has just migrated), the SwMI where it was previously registered shall remove the subscriber's information from
its I-VDB.
A MS/LS may contain more than one TETRA Subscriber Identity (TSI) family and the migration procedure shall have
to be completed for each of them independently.
5.1.1.4 Group attachment scenarios
The group attachment procedure enables individual subscribers registered in another SwMI than the home SwMI of a
group of which they are member to participate in calls to that group.
NOTE: An individual subscriber member of a group may be registered in another SwMI than the home SwMI of
that group because either:
 his home SwMI is the same as that of the group and he has migrated; or
 his home SwMI is different and either he is registered in his home SwMI or he has migrated into
another SwMI than the group home SwMI.
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As a result of the group attachment, the home SwMI shall know to which SwMIs the group call will be extended and
those SwMIs will themselves handle group call set-ups.
Figure 5.2 illustrates the ISI configuration for the attachment to a group of which an individual user is a member, of the
visited SwMI where that subscriber has migrated when the group and that subscriber have the same home SwMI.
ISI
home SwMI visited SwMI
Figure 5.2: Group attachment scenario
When a new SwMI is attached to a group:
• the group home SwMI shall update the G-HDB with that new attachment; and
• that new SwMI shall record in the G-VDB the identity of the individual subscriber member of the group to be
used for the subscribers' group attachment tracking within that SwMI and the group attachment tracking for
that SwMI, i.e. which individual subscribers are attached to the group in that SwMI. In addition, that SwMI
shall fetch the migration profiles for the group (sent through ANF-ISIMM else defined by default) and save
them in the G-VDB. The migration profiles shall indicate the service authorizations for the group in that
SwMI. That SwMI shall also allocate the (V)GSSI for the group as defined in clause 7.2.2 of ETSI
EN 300 392-1 [1].
An individual subscriber may attach to one or more groups and each of those shall be attached independently.
5.1.2 Group linking configurations
The group linking shall enable the combining of groups with different home SwMIs (over the ISI). The call made to a
group linked to another one shall result in a combined group call set-up to the members of the groups. The combined
group call is described in the document defining ANF-ISIGC.
In order to support the group linking functionality in different SwMIs, the following roles are defined for SwMIs for
group linking establishment:
• linking controlling SwMI: The group linking controlling SwMI controls the making of the linking
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