SIST EN 300 395-1 V1.2.1:2006

• Abstract:

  The present document is an introduction to the other parts of this multi-part deliverable dealing with the speech processing functions in the TETRA system. In addition to this introduction, the present document contains the full specification of the speech CODEC including provisions for specific cases of operation and optional functionalities plus CODEC conformance testing. The present document also contains the full specification for the optional AMR CODEC as implemented within the TETRA system. In the present document, a general overview of the speech processing parts is given with reference to the multi-part deliverable where each part is specified in detail.

• Status: Published
• Publication Date: 31-Mar-2006
• ICS: 33.070.10 - Terrestrial Trunked Radio (TETRA)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-2006
• Due Date: 01-Apr-2006
• Completion Date: 01-Apr-2006
• Ref Project: ETSI EN 300 395-1 V1.2.1 (2005-01) - Terrestrial Trunked Radio (TETRA); Speech codec for full-rate traffic channel; Part 1: General description of speech functions

SIST EN 300 395-1 V1.2.1:2006 is the Slovenian adoption of the ETSI standard for Terrestrial Trunked Radio (TETRA) speech coding on the full-rate traffic channel. It gives the general description of the speech functions in the TETRA system, including the mandatory full-rate speech CODEC and the optional AMR speech codec, and points to the companion parts for the detailed codec, specific operating features, and conformance testing. It is aimed at people who design, integrate, test, or buy TETRA equipment and need to understand how the speech path and its control functions are organized.

What does SIST EN 300 395-1 V1.2.1:2006 specify?

SIST EN 300 395-1 V1.2.1:2006 is Part 1 of a multi-part TETRA speech codec deliverable. It serves as an overview of the speech processing functions and also states the core behavior of the speech CODEC, the speech control unit, conformance testing, and the optional AMR codec.

The document is organized into these main clauses:

• Clause 4 - General
• Clause 5 - Full rate speech CODEC
• Clause 6 - Speech control unit
• Clause 7 - Conformance testing
• Clause 8 - AMR speech codec
• Annex A - Bibliography

What are the key requirements of SIST EN 300 395-1 V1.2.1:2006?

SIST EN 300 395-1 V1.2.1:2006 makes the full-rate speech codec mandatory for all TETRA equipment, while AMR support is optional. In practice, this means a TETRA device cannot claim speech interoperability without the full-rate codec, but it may choose whether to implement AMR.

Clause 4 states that the speech path uses 16-bit linear Pulse Code Modulated (PCM) audio at the interface, and Figure 1 shows the reference configuration between the Mobile Station (MS) and the Base Station (BS). That matters because implementers must map their audio and network interfaces to the standardized speech path shown in the document.

Clause 5 describes the full-rate codec chain and points to EN 300 395-2 for the detailed source encoder and decoder. The text states an 8 000 sample/s rate, the 240-sample to 137-bit mapping, and the bit exact description of the codec. For a reader, this is the basis for interoperability testing and for checking that an implementation follows the specified frame size and coding behavior.

Clause 5 also states that the speech coding model is Code-Excited Linear Predictive (CELP), implemented as Algebraic CELP (ACELP). That tells designers what kind of coding structure to expect and helps them align implementation, performance evaluation, and debugging.

Clause 6 covers lost frame aspects, comfort noise aspects, the importance parameter, and the homing function. The speech control functions are used to hide missing frames, generate comfort noise after longer frame loss, compute an importance parameter for each speech frame, and reset the coder and decoder to a known state. In practice, these functions support call continuity, discontinuous transmission control, and repeatable testing.

Clause 6.4 and clause 7 together make bit exact behavior and conformance testing important. The document says that test sequences should produce corresponding output sequences when modules are in their home-state, and that specific operating features are disabled for conformance testing. That means test labs must control initial state carefully when verifying compliance.

Clause 8 states that if AMR is implemented within the network or mobile station, only the 4.75 kbit/s mode shall be used, as specified in TS 126 090, and Source Controlled Rate (SCR) shall not be used. For procurement and system design, this limits AMR use inside TETRA to one defined mode.

What terms does SIST EN 300 395-1 V1.2.1:2006 define?

• ACELP - Algebraic Code-Excited Linear Predictive coding, the codec technique used by the TETRA speech codec.
• AMR - Advanced Multi-Rate, the optional speech codec supported only in the specified mode.
• BS - Base Station, the network-side point shown in the reference configuration.
• CELP - Code-Excited Linear Predictive coding, the speech coding model used as the basis for the codec.
• MFG - Missing Frame Generation, a function used to synthesize speech parameters when frames are lost.
• MFS - Missing Frame Substitution, a function used to replace missing frame information with substitute parameters.
• MS - Mobile Station, the user-side equipment in the TETRA speech path.
• PCM - Pulse Code Modulated, the audio format used at the speech codec interface.
• SCR - Source Controlled Rate, a mode that shall not be used within TETRA for AMR.

Who uses SIST EN 300 395-1 V1.2.1:2006?

This standard is used by TETRA equipment manufacturers, speech codec developers, radio system integrators, conformance test laboratories, and network planners. They use it to understand the speech architecture, implement the codec path, verify frame handling and reset behavior, and check whether a device supports the required TETRA speech functions.

Which standards are used with SIST EN 300 395-1 V1.2.1:2006?

Standard	What it contributes
EN 300 395-2	Detailed TETRA codec description, including the source encoder, channel encoder, decoder, performance, and bit exact C description
EN 300 395-3	Specific operating features such as frame stealing, comfort noise, importance, and homing-related functions
EN 300 395-4	Codec conformance testing and the digital test sequences used to verify behavior
EN 300 392-2	Definitions and abbreviations used by the document, and the air interface context
EN 300 392-7	Messages at standardized interface points 3, 4, and 8
TS 126 090	AMR speech codec transcoding functions and the 4.75 kbit/s mode used in TETRA

What does the SIST EN 300 395-1 V1.2.1:2006 document contain?

The document contains a reference configuration figure for the speech path, showing the functions between audio input and output in the MS and the digital network interface in the BS. It identifies standardized interface points, the exchange of encoded speech and control information, and the role of encryption and channel coding in the overall path.

It also contains the overview text that ties Part 1 to the rest of the series, plus the clauses on the full-rate codec, control functions, conformance testing, and AMR support. Annex A provides the bibliography, and the foreword lists the companion parts of the TETRA speech codec series.

SLOVENSKI STANDARD
01-april-2006
Prizemni snopovni radio (TETRA) – Govorni kodek za prometni kanal s polno
hitrostjo – 1. del: Splošni opis govornih funkcij
Terrestrial Trunked Radio (TETRA); Speech codec for full-rate traffic channel; Part 1:
General description of speech functions
Ta slovenski standard je istoveten z: EN 300 395-1 Version 1.2.1
ICS:
33.070.10 Prizemni snopovni radio Terrestrial Trunked Radio
(TETRA) (TETRA)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

European Standard (Telecommunications series)

Terrestrial Trunked Radio (TETRA);
Speech codec for full-rate traffic channel;
Part 1: General description of speech functions

2 ETSI EN 300 395-1 V1.2.1 (2005-01)

Reference
REN/TETRA-05113-1
Keywords
TETRA, codec
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ETSI
3 ETSI EN 300 395-1 V1.2.1 (2005-01)
Contents
Intellectual Property Rights.4
Foreword.4
1 Scope.5
2 References.5
3 Definitions and abbreviations.5
3.1 Definitions.5
3.2 Abbreviations.5
4 General.6
5 Full rate speech CODEC .6
6 Speech control unit.8
6.1 Lost frame aspects.8
6.2 Comfort noise aspects .8
6.3 Importance parameter.8
6.4 Homing function.8
7 Conformance testing.8
8 AMR speech codec.9
Annex A (informative): Bibliography.10
History .11

ETSI
4 ETSI EN 300 395-1 V1.2.1 (2005-01)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This European Standard (Telecommunications series) has been produced by ETSI Project Terrestrial Trunked Radio
(TETRA).
The present document is part 1 of a multi-part deliverable covering speech codec for full-rate traffic channel, as
identified below:
Part 1: "General description of speech functions";
Part 2: "TETRA codec";
Part 3: "Specific operating features";
Part 4: "Codec conformance testing".

National transposition dates
Date of adoption of this EN: 21 January 2005
Date of latest announcement of this EN (doa): 30 April 2005
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 October 2005
Date of withdrawal of any conflicting National Standard (dow): 31 October 2005

ETSI
5 ETSI EN 300 395-1 V1.2.1 (2005-01)
1 Scope
The present document is an introduction to the other parts of this multi-part deliverable dealing with the speech
processing functions in the TETRA system. In addition to this introduction, the present document contains the full
specification of the speech CODEC including provisions for specific cases of operation and optional functionalities plus
CODEC conformance testing. The present document also contains the full specification for the optional AMR CODEC
as implemented within the TETRA system. In the present document, a general overview of the speech processing parts
is given with reference to the multi-part deliverable where each part is specified in detail.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
[1] ETSI TS 126 090: "Universal Mobile Telecommunications System (UMTS); Mandatory Speech
Codec speech processing functions AMR Speech Codec - Transcoding functions
(3GPP TS 26.090 Release 4)".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in EN 300 392-2, clause 3 apply.
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in EN 300 392-2, clause 3 and the following apply:
ACELP Algebraic CELP
AMR Advanced Multi-Rate
BS Base Station
CELP Code-Excited Linear Predictive
MFG Missing Frame Generation
MFS Missing Frame Substitution
MS Mobile Station
PCM Pulse Code Modulated
SCR Source Controlled Rate
ETSI
6 ETSI EN 300 395-1 V1.2.1 (2005-01)
4 General
Figure 1 illustrates a refe
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