T-172 -

The present document defines the Terrestrial Trunked Radio system (TETRA) supporting Voice plus Data (V+D). It
specifies:
• general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);
• the interworking between TETRA networks;
• the interworking of TETRA networks with other networks, via gateways;
• the supplementary services applicable to the basic TETRA tele- or bearer services.
The TETRA V+D interworking - basic operation part defines the interworking between TETRA networks over the
corresponding interface: the Inter-System Interface (ISI). It comprises the following sub-parts:
• ISI general design;
• 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);
• Additional Network Feature - ISI Mobility Management (ANF-ISIMM);
• Speech Format Implementation for Circuit Mode Transmission;
• Speech Format Implementation for Packet Mode Transmission.
The present document is the ANF-ISIGC sub-part.
In analogy with Recommendation ITU-T I.130 [i.6], the stage one, stage two and stage three of the three level structure
is used to describe the TETRA Inter-System Interface services as provided by European Private or Public Trunked
Radio System operators:
• Stage 1, is an overall service description, from the service subscriber's and user's standpoint;
• Stage 2, identifies the functional capabilities and information flows needed to support the services described in
stage 1; and
NOTE: The information flows in stage 2 have been drawn as Message Sequence Charts (MSC). Therefore PISN
basic call information flows are also shown together with the ANF-ISIGC information flows.
• Stage 3, defines the signalling system protocols and switching functions needed to implement the services
described in stage 1.
The present document details the Interworking Basic Operation of the Terrestrial Trunked Radio system (TETRA).
Specifically this sub-part details the stage 1 aspects (overall service description) of the ANF-ISIGC as seen from the
TETRA Switching and Maintenance Infrastructure point of view at the Inter-System Interface (ISI). It details the
stage 2 aspects (functional partitioning) of ANF-ISIGC which includes the identification of the functional entities and
the flows between them, and finally it details the stage 3 signalling protocols for the ANF-ISIGC services, i.e. the
protocols at the relevant reference points between the functional entities defined in stage 2.
The ANF-ISIGC service specifies:
• TETRA Group Call Clear Speech over the ISI, acknowledged and unacknowledged;
• TETRA Group Call End-to-End Encrypted Speech over the ISI;
• TETRA Group Call Circuit Mode one slot data over the ISI;
• TETRA Group Call Circuit Mode one slot End-to-End Encrypted data over the ISI;
• TETRA Group Call Circuit Mode N × 2,4 kbit/s, N × 4,8 kbit/s or N × 7,2 kbit/s data, with N = 2, 3 or 4;
• TETRA Group Call Circuit Mode N × 2,4 kbit/s N × 4,8 kbit/s or N × 7,2 kbit/s End-to-End Encrypted data,
with N = 2, 3 or 4.

REN/TCCE-03248

REN/TETRA-03207

REN/TETRA-08196

REN/TETRA-08196

REN/TETRA-03207

The present document defines the Terrestrial Trunked Radio (TETRA) system supporting Voice plus Data (V+D). It specifies:
- general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);
- the system bearer and mobility management services, and the corresponding air interface protocols;
- the interworking between TETRA networks;
- the interworking 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 terminal equipment;
- the supplementary services applicable to the basic TETRA tele- or bearer services.
The TETRA V+D interworking - basic operation part defines the interworking between TETRA networks over the corresponding interface: the Inter-System Interface (ISI). It comprises the following subparts:
- ISI general design;
- Additional Network Feature - ISI Individual Call (ANF-ISIIC);
- Additional Network Feature - ISI Group Call (ANF-ISIGC);
- Additional Network Feature - ISI Short Data service (ANF-ISISDS);
- Additional Network Feature - ISI Mobility Management (ANF-ISIMM);
- 8 kbit/s encoding of user information at the ISI.
The present document is the ANF-ISIIC sub-part.
ANF-ISIIC enables calls to be set-up by a user registered in one TETRA network to another user registered in another TETRA network, operating at the ISI of both SwMIs. It also supports call restoration when a user has migrated to another TETRA network during an established call. Additionally, ANF-ISIIC allows TETRA signalling information to be passed from a TETRA SwMI to another TETRA SwMI supporting the TETRA individual call procedures as defined in clauses 11 and 14 of EN 300 392-2 [1]. Like all other Additional Network Feature (ANF) specifications, those of ANF-ISIIC are produced in three stages, according to the method described in ITU-T Recommendation I.130 [i.5]. The present document contains the stage 1 and 2 descriptions of ANF-ISIIC, and its partial stage 3 description. The stage 1 description specifies the ANF as seen by its users, which are essentially the individual call control entities in both TETRA networks. The stage 2 description identifies the functional entities involved in the ANF and the information flows between them. And the partial stage 3 description of ANF-ISIIC specifies its protocol. NOTE: According to ITU-T Recommendation I.130 [i.5], the stage 3 description of a bearer or tele-service addresses the network implementation aspects. Consequently, it comprises two steps: the specifications of all protocols at the various reference points involved in any of the service procedures (notably the service operation) are the first step of the stage 3 description, and the specifications of the functions of the corresponding network entities are its second step. The latter have not been provided since they can be derived from the specification of the functional entity
actions in the stage 2 description. The present document applies to TETRA networks which support inter-TETRA individual calls. More specifically, it applies to their Circuit Mode Control Entities (CMCE), as defined in clause 14.2 of EN 300 392-2 [1], and to their ANF-ISIIC entities defined in the stage 2 description.

The present document defines the Terrestrial Trunked Radio system (TETRA) supporting Voice plus Data (V+D). It specifies:
- general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);
- the system bearer and mobility management services, and the corresponding air interface protocols;
- the interworking between TETRA networks;
- the interworking of TETRA networks with other networks, via gateways;
- the peripheral equipment interface on the mobile station;
- the security protocols and mechanisms applicable to TETRA networks and to TETRA terminal equipment;
- the supplementary services applicable to the basic TETRA tele- or bearer services.
The TETRA V+D interworking - basic operation part defines the interworking between TETRA networks over the corresponding interface: the Inter-System Interface (ISI). It comprises the following subparts:
- ISI general design;
- Additional Network Feature - ISI Individual Call (ANF-ISIIC);
- Additional Network Feature - ISI Group Call (ANF-ISIGC);
- Additional Network Feature - ISI Short Data service (ANF-ISISDS);
- Additional Network Feature - ISI Mobility Management (ANF-ISIMM);
- 8 kbit/s encoding of user information at the ISI.
The present document specifies the Additional Network Function (ANF) - Inter-System Interface (ISI) Short Data service (ANF-ISISDS) which is part of the Interworking Basic Operation of the Terrestrial Trunked Radio system (TETRA) supporting Voice and Data (V+D). Specifically the present document details the stage 1, 2 and 3 aspects of the ANF-ISISDS as seen from the TETRA Switching and Maintenance Infrastructure (SwMI) point of view at the Inter System Interface (ISI). This service comprises of:
- TETRA user defined short message transmission over the ISI to individual and group addresses;
- TETRA pre-defined short message transmission over the ISI to individual and group addresses.
ANF-ISISDS enables short data and status messages to be set-up and transferred between a user registered in one TETRA network to another user registered in another TETRA network, operating at the ISI of both SwMIs. Like all other Additional Network Feature (ANF) specifications, those of ANF-ISISDS are produced in three stages, according to the method described in ITU-T Recommendation I.130 [4]. The present document contains the stage 1 and 2 descriptions of ANF-ISIIC, and its partial stage 3 description. The stage 1 description specifies the ANF as seen by its users, which are essentially the individual call control entities in both TETRA networks. The stage 2 description identifies the functional entities involved in the ANF and the information flows between them. The partial stage 3 description of ANF-ISISDS specifies its protocol.

REN/TETRA-03195

REN/TETRA-03193

The present document defines the Terrestrial Trunked Radio (TETRA) system supporting Voice plus Data (V+D). It specifies:
• general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);
• the system bearer and mobility management services, and the corresponding air interface protocols;
• the interworking between TETRA networks;
• the interworking 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 terminal equipment;
• the supplementary services applicable to the basic TETRA tele- or bearer services.
The TETRA V+D interworking - basic operation part defines the interworking between TETRA networks over the corresponding interface: the Inter-System Interface (ISI). It comprises the following subparts:
• ISI general design;
• 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);
• Additional Network Feature - ISI Mobility Management (ANF-ISIMM);
• 8 kbit/s encoding of user information at the ISI.
The present document is the ANF-ISIIC sub-part. ANF-ISIIC enables calls to be set-up by a user registered in one TETRA network to another user registered in another TETRA network, operating at the ISI of both SwMIs. It also supports call restoration when a user has migrated to another TETRA network during an established call. Additionally, ANF-ISIIC allows TETRA signalling information to be passed from a TETRA SwMI to another TETRA SwMI supporting the TETRA individual call procedures as defined in clauses 11 and 14 of EN 300 392-2 [1].
Like all other Additional Network Feature (ANF) specifications, those of ANF-ISIIC are produced in three stages, according to the method described in ITU-T Recommendation I.130 [11]. The present document contains the stage 1 and 2 descriptions of ANF-ISIIC, and its partial stage 3 description. The stage 1 description specifies the ANF as seen by its users, which are essentially the individual call control entities in both TETRA networks. The stage 2 description identifies the functional entities involved in the ANF and the information flows between them. And the partial stage 3 description of ANF-ISIIC specifies its protocol.
NOTE: According to ITU-T Recommendation I.130 [11], the stage 3 description of a bearer or tele-service addresses the network implementation aspects. Consequently, it comprises two steps: the specifications of all protocols at the various reference points involved in any of the service procedures (notably the service operation) are the first step of the stage 3 description, and the specifications of the functions of the corresponding network entities are its second step. The latter have not been provided since they can be derived from the specification of the functional entity actions in the stage 2 description. The present document applies to TETRA networks which support inter-TETRA individual calls. More specifically, it applies to their Circuit Mode Control Entities (CMCE), as defined in clause 14.2 of EN 300 392-2 [1], and to their ANF-ISIIC entities defined in the stage 2 description.

REN/TETRA-03161

The present document defines the Terrestrial Trunked Radio system (TETRA) supporting Voice plus Data (V+D). It specifies:
- general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);
- the system bearer and mobility management services, and the corresponding air interface protocols;
- the interworking between TETRA networks;
- the interworking 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 terminal equipment;
- the supplementary services applicable to the basic TETRA tele- or bearer services.
The TETRA V+D interworking - basic operation part defines the interworking between TETRA networks over the corresponding interface: the Inter-System Interface (ISI). It comprises the following subparts:
- ISI general design;
- 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);
- Additional Network Feature - ISI Mobility Management (ANF-ISIMM);
- 8 kbit/s encoding of user information at the ISI.
The present document specifies the Additional Network Function (ANF) - Inter-System Interface (ISI) Short Data service (ANF-ISISD) which is part of the Interworking Basic Operation of the Terrestrial Trunked Radio system (TETRA) supporting Voice and Data (V+D). Specifically the present document details the stage 1, 2 and 3 aspects of the ANF-ISISD as seen from the TETRA Switching and Maintenance Infrastructure (SwMI) point of view at the Inter System Interface (ISI). This service comprises of:
- TETRA user defined short message transmission over the ISI to individual and group addresses;
- TETRA pre-defined short message transmission over the ISI to individual and group addresses.
ANF-ISISD enables short data and status messages to be set-up and transferred between a user registered in one TETRA network to another user registered in another TETRA network, operating at the ISI of both SwMIs. Like all other Additional Network Feature (ANF) specifications, those of ANF-ISISD are produced in three stages, according to the method described in ITU-T Recommendation I.130 [4]. The present document contains the stage 1 and 2 descriptions of ANF-ISIIC, and its partial stage 3 description. The stage 1 description specifies the ANF as seen by its
users, which are essentially the individual call control entities in both TETRA networks. The stage 2 description identifies the functional entities involved in the ANF and the information flows between them. The partial stage 3 description of ANF-ISISD specifies its protocol.

The present document defines the Terrestrial Trunked Radio (TETRA) system supporting Voice plus Data (V+D). It specifies:
• general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);
• the system bearer and mobility management services, and the corresponding air interface protocols;
• the interworking between TETRA networks;
• the interworking 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 terminal equipment;
• the supplementary services applicable to the basic TETRA tele- or bearer services.
The TETRA V+D interworking - basic operation part defines the interworking between TETRA networks over the corresponding interface: the Inter-System Interface (ISI). It comprises the following subparts:
• ISI general design;
• 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);
• Additional Network Feature - ISI Mobility Management (ANF-ISIMM);
• 8 kbit/s encoding of user information at the ISI.
The present document is the ANF-ISIIC sub-part.
ANF-ISIIC enables calls to be set-up by a user registered in one TETRA network to another user registered in another TETRA network, operating at the ISI of both SwMIs. It also supports call restoration when a user has migrated to another TETRA network during an established call. Additionally, ANF-ISIIC allows TETRA signalling information to be passed from a TETRA SwMI to another TETRA SwMI supporting the TETRA individual call procedures as defined in clauses 11 and 14 of EN 300 392-2 [1].
Like all other Additional Network Feature (ANF) specifications, those of ANF-ISIIC are produced in three stages, according to the method described in ITU-T Recommendation I.130 [11]. The present document contains the stage 1 and 2 descriptions of ANF-ISIIC, and its partial stage 3 description. The stage 1 description specifies the ANF as seen by its users, which are essentially the individual call control entities in both TETRA networks. The stage 2 description identifies the functional entities involved in the ANF and the information flows between them. And the partial stage 3 description of ANF-ISIIC specifies its protocol.
NOTE: According to ITU-T Recommendation I.130 [11], the stage 3 description of a bearer or tele-service addresses the network implementation aspects. Consequently, it comprises two steps: the specifications of all protocols at the various reference points involved in any of the service procedures (notably the service operation) are the first step of the stage 3 description, and the specifications of the functions of the corresponding network entities are its second step. The latter have not been provided since they can be derived from the specification of the functional entity actions in the stage 2 description. The present document applies to TETRA networks which support inter-TETRA individual calls. More specifically, it applies to their Circuit Mode Control Entities (CMCE), as defined in clause 14.2 of EN 300 392-2 [1], and to their ANF-ISIIC entities defined in the stage 2 description.

The present document defines the mobility management of interworking at the Inter-System Interface (ISI) for Terrestrial Trunked Radio (TETRA) system supporting Voice plus Data (V+D).
The TETRA V+D Inter-working - basic operation part defines the Inter-System Interface (ISI) between the SwMIs as specified in the following sub-parts:
• Additional Network Feature - Inter-System Interface General Description (ANF-ISIGD);
• 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-ISISD);
• Additional Network Feature - Inter-System Interface Mobility Management (ANF-ISIMM).
NOTE: These ENs are produced in analogy with the ITU-T Recommendation I.130 [8].
The present document contains the ANF-ISIMM part. The ANF-ISIMM part defines additional Mobility Management (MM) services to the SwMIs. If supported, the ANF-ISIMM services complement the intra-SwMI-MM, authentication and key management services. In support of these, the ANF-ISIMM enables the invocation and operation of these services between the SwMIs over the ISI. Thus, ANF-ISIMM offers the following services:
• migration and restricted migration;
• individual subscriber and group profile update;
• profile update;
• de-registration;
• group attachment/detachment;
• individual subscriber and group database fault recovery;
• authentication, one-directionally or mutually between the individual subscriber and the home SwMI;
• Over-The-Air-Re-keying (OTAR) for Static Cipher Key (SCK) generation and SCK delivery.
For the following service only the stage 1 descriptions are included:
• linking/unlinking of groups.

The present document defines the Terrestrial Trunked Radio system (TETRA) supporting Voice plus Data (V+D). It specifies:
• general design aspects (e.g. reference points, numbering and addressing, or protocol architecture);
• the interworking between TETRA networks;
• the interworking of TETRA networks with other networks, via gateways;
• the supplementary services applicable to the basic TETRA tele- or bearer services.
The TETRA V+D interworking - basic operation part defines the interworking between TETRA networks over the corresponding interface: the Inter-System Interface (ISI). It comprises the following sub-parts:
• ISI general design;
• 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);
• Additional Network Feature - ISI Mobility Management (ANF-ISIMM);
• Speech Format Implementation for Circuit Mode Transmission;
• Speech Format Implementation for Packet Mode Transmission.
The present document is the ANF-ISIGC sub-part. In analogy with ITU-T Recommendation I.130 [19], the stage one,  stage two and stage three of the three level structure is used to describe the TETRA Inter-System Interface services as provided by European Private or Public Trunked Radio System operators:
• Stage 1, is an overall service description, from the service subscriber's and user's standpoint;
• Stage 2, identifies the functional capabilities and information flows needed to support the services described in stage 1; and
NOTE: The information flows in stage 2 have been drawn as Message Sequence Charts (MSC). Therefore PISN basic call information flows are also shown together with the ANF-ISIGC information flows.
• Stage 3, defines the signalling system protocols and switching functions needed to implement the services described in stage 1.
The present document details the Interworking Basic Operation of the Terrestrial Trunked Radio system (TETRA). Specifically this sub-part details the stage 1 aspects (overall service description) of the ANF-ISIGC as seen from the TETRA Switching and Maintenance Infrastructure point of view at the Inter-System Interface (ISI). It details the stage 2 aspects (functional partitioning) of ANF-ISIGC which includes the identification of the functional entities and the flows between them, and finally it details the stage 3 signalling protocols for the ANF-ISIGC services, i.e. the protocols at the relevant reference points between the functional entities defined in stage 2.
The ANF-ISIGC service specifies:
• TETRA Group Call Clear Speech over the ISI, acknowledged and unacknowledged;
• TETRA Group Call End-to-End Encrypted Speech over the ISI;
• TETRA Group Call Circuit Mode one slot data over the ISI;
• TETRA Group Call Circuit Mode one slot End-to-End Encrypted data over the ISI;
• TETRA Group Call Circuit Mode N × 2,4 kbit/s, N × 4,8 kbit/s or N × 7,2 kbit/s data, with N = 2, 3 or 4;
• TETRA Group Call Circuit Mode N × 2,4 kbit/s N × 4,8 kbit/s or N × 7,2 kbit/s End-to-End Encrypted data, with N = 2, 3 or 4.

The present document specifies the following identification supplementary services: Calling Line Identification Presentation (SS-CLIP), Connected Line Identification Presentation (SS-COLP), Calling Line Identification Restriction (SS-CLIR) and Connected Line Identification Restriction (SS-COLR), which are applicable to various basic services supported by TETRA Switching and Management Infrastructures (SwMIs). TETRA basic services are specified in EN 300 392-2 [1].
Calling Line Identification Presentation (SS-CLIP) is a supplementary service which is offered to the connected user and which provides the calling user's TETRA number to the connected user. Connected Line Identification Presentation (SS-COLP) is a supplementary service which is offered to the calling user and which provides the called (connected) user's TETRA number to the calling user. Calling Line Identification Restriction (SS-CLIR) is a supplementary service offered to a calling user to restrict presentation of that user's TETRA number to another user. Connected Line Identification Restriction (SS-COLR) is a supplementary service offered to a connected user to restrict
presentation of that user's TETRA number to another user.
NOTE 1: For readability of the present document, and contrary to ECMA-148 [2], SS-CLIR and SS-COLR are split
in the present document. As a TETRA network implementation option, override capability shall be provided to selected users; for a group call, override shall be defined against the group identity and not against each individual member of the group.
NOTE 2: This capability is provided in ECMA-148 [2].
Supplementary service specifications are produced in three stages, according to the method described in ETS 300 387 [6]. The present document contains the stage 1 specifications of SS-CLIP, SS-COLP and SS-CLIR. The stage 1 descriptions specify the supplementary services as seen by users of SwMIs. The present document is applicable to circuit mode TETRA teleservices and bearer services only. This first version of the present document was presented as a delta document to ECMA-148 [2]. This version has been redrafted still based on the text of ECMA-148 [2] but includes now the full applicable text so as to be more readable.

REN/TETRA-03089

REN/TETRA-03087

REN/TETRA-03088

REN/TETRA-03086

REN/TETRA-03092

Updated to version 8.0.0 CRs from SMG#31

SUBJECT Addition of mu-law (PCS 1900).

This European Telecommunication Standard (ETS) contains an electronic copy of the ANSI-C code for the GSM half rate codec. The ANSI-C code i s necessary for a bit exact implementation of the half rate speech tra nscoder (GSM 06.20 (ETS 300 969) [2]), Voice Activity Detector (GSM 06 .42 (ETS 300 973) [6]), comfort noise (GSM 06.22 (ETS 300 971) [4]), D iscontinuous Transmission (GSM 06.41 (ETS 300 972) [5]) and example so lutions for substituting and muting of lost frames (GSM 06.21 (ETS 300 970) [3])

Adaptive Multi- Rate (AMR) speech processing functions

Updated to Version 8.0.0 CRs from SMG#31

Upgrade from Phase 2+ to Release 1997

Upgrade from Phase 2+ to Release 1998

.

To produce a PICS proforma for Direct Mode Operation of Mobile terminals

Adaptive Multi- Rate (AMR) Test sequences

EN created for GSM Phase2 MS type approval purposes (a revision of GSM Phase 2+ ETS)

Upgrade from Phase 2+ to Release 1997

Updated to version 8.0.0 CRs from SMG#31

Option to DE/RES-06001 for Direct Mode Operation of mobile terminals with or without network coverage. Split on 2/95 into three parts: Part 1: General network design Part 2: Air interface Part 3: Security

SUBJECT Addition of mu-law (PCS 1900).

CR SA#8

To produce a PICS proforma for Direct Mode Operation of Mobile terminals

Upgrade from Phase 2+ to Release 1997

This European Telecommunications Standard (ETS) specifies the speech c odec to be used for the GSM half rate channel. It also specifies the t est methods to be used to verify that the codec implementation complie s with this ETS. The requirements are mandatory for the codec to be used either in GSM Mobile Stations (MS)s or Base Station Systems (BSS)s that utilize the half rate GSM speech traffic channel.

EN created for GSM Phase2 MS type approval purposes (a revision of GSM Phase 2+ ETS)

CR @ SA#6

Upgrade from Phase 2+ to Release 1998

Adaptive Multi- Rate (AMR)  Comfort noise

Updated to version 8.0.0 CRs from SMG#31

This part 7 of the ETS contains an electronic copy of the ANSI-C code for the GSM half rate codec, necessary for a bit exact implementation of the half rate speech transcoder (see part 2 of this ETS - GSM 06.20), Voice Activity Detection (see part 6 of this ETS - GSM 06.42), comfort noise (see part 4 of this ETS - GSM 06.22), Discontinuous Transmission (see part 5 of this ETS - GSM 06.41) and example solutions for sustituting and muting lost frames (see part 3 of this ETS - GSM 06.21).

This European Telecommunication Standard (ETS) defines a frame substit ution and muting procedure which shall be used by the Receive (RX) Dis continuous Transmission (DTX) handler when one or more lost or unrelia ble speech or SIlence Descriptor (SID) frames are received from the Ra dio Sub System (RSS). The requirements of this ETS are mandatory for implementation in all G SM Base Station Systems (BSS)s and Mobile Stations (MS)s capable of su pporting the half rate speech traffic channel.

CR @ TSG#7

This European Telecommunication Standard (ETS) specifies the Voice Activity Detector (VAD) to be used in the Discontinuous Transmission (DTX) as described in GSM EFR 06.31. It also specifies the test methods to be used to verify that a VAD complies with this ETS.  The requirements are mandatory on any VAD to be used either in GSM Mobile Stations (MS)s or Base Station Systems (BSS)s that utilise the enhanced full-rate speech traffic channel.