SIST ETS 300 967 E1:2003

• Abstract:

  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])

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.070.50 - Global System for Mobile Communication (GSM)
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Dec-2003
• Due Date: 01-Dec-2003
• Completion Date: 01-Dec-2003
• Mandate: T-172
• Ref Project: ETSI ETS 300 967 ed.1 (1997-05) - Digital cellular telecommunications system; Half rate speech; ANSI-C code for the GSM half rate speech codec ANSI-C code for the GSM half rate speech codec (GSM 06.06 version 5.0.1)

SIST ETS 300 967 E1:2003 is the Slovenian standard for the GSM half rate speech codec ANSI-C code, based on ETS 300 967 from ETSI. It provides the electronic code needed for bit-exact implementation of the half rate speech transcoder, Voice Activity Detector (VAD), comfort noise, Discontinuous Transmission (DTX), and example lost-frame substitution and muting functions. It is intended for people implementing, integrating, or verifying GSM half rate speech traffic channels.

What does SIST ETS 300 967 E1:2003 specify?

SIST ETS 300 967 E1:2003 specifies the ANSI-C code for the GSM half rate speech codec and explains how the code is organized and used. In practice, it is the reference code package for software that must match the GSM half rate speech specifications closely.

Clause	What it covers
1	Scope of the code package
2	Normative references
3	Definitions and abbreviations
4	C code structure, directory layout, and execution
5	ANSI-C code for the GSM half rate speech codec

The scope ties the code to bit-exact implementation of GSM 06.20, GSM 06.42, GSM 06.22, GSM 06.41, and the example lost-frame handling in GSM 06.21. That matters because implementers can use the code as a functional reference when building compatible encoder and decoder software.

What are the key requirements of SIST ETS 300 967 E1:2003?

SIST ETS 300 967 E1:2003 is mainly a code-definition and implementation reference, so its important points are about structure, file handling, and execution behavior.

Scope and intended use

Clause 1 states that the standard contains an electronic copy of the ANSI-C code for the GSM half rate codec. The code is necessary for a bit-exact implementation of the speech transcoder, VAD, comfort noise, DTX, and lost-frame substitution and muting functions. In practice, this tells developers which GSM half rate speech functions are covered by the code package.

Reference framework

Clause 2 anchors the code to related GSM documents and to ANSI 9899 (1990) for the C language. This matters because the code is not a standalone algorithm description - it is meant to be read together with the GSM speech and test-sequence specifications and with standard C.

Code package structure

Clause 4.1 organizes the diskette into a source-code directory, example data, utilities, executables, and a readme file. The text explains which files are essential and which support installation, building, or testing. For a user, that means the package is not just source code - it also includes the data and tools needed to verify the implementation.

File formats and verification

Clause 4.1 says the example data files are written and read as 16-bit words and may need byte swapping on some platforms. It also points to GSM 06.07 test sequences for final verification. In practice, this is the part that helps an implementer check whether a target machine handles data files correctly.

Program execution

Clause 4.2 defines two programs: gsm_hr for speech coding and reid for encoder/decoder interface handling. gsm_hr runs in encoding-only mode or decoding-only mode, with specific binary input and output file types for each direction. This is important because encoder output and decoder input files are not the same format, so the conversion step must be handled correctly.

Code hierarchy

Clause 4.3 presents call graphs for the decoder, encoder, LPC quantization, open-loop lag search, subframe processing, comfort noise, and VAD. These graphs show how the functions are structured and what the deeper processing steps are. For readers, the value is in understanding where the major processing blocks sit before integrating or debugging the code.

Attached code

Clause 5 contains the ANSI-C code itself on the attached diskette. That is the deliverable implementers would use as the executable reference.

What terms does SIST ETS 300 967 E1:2003 define?

Clause 3 points readers to related GSM speech specifications for the full definitions of technical terms. It also gives the abbreviations used in the document.

• ANSI - American National Standards Institute, the body named for the C language reference and the abbreviation list.
• DS-HD - Double Sided High Density, the floppy-disk format used for code dissemination.
• ETS - European Telecommunication Standard, the type of standard this document belongs to.
• GSM - Global System for Mobile communications, the mobile system family covered by the code.
• I/O - Input/Output, a common term used for file and data handling.
• ROM - Read Only Memory, used in the code structure description for stored data.

Who uses SIST ETS 300 967 E1:2003?

SIST ETS 300 967 E1:2003 is used by GSM software developers, codec implementers, and test engineers working on half rate speech traffic channels. It is also relevant to integration teams and quality staff who need to verify bit-exact behavior against the GSM speech specifications.

In practice, users apply it when building encoder and decoder software, checking file formats, running installation verification data, translating encoder output for decoder input, and comparing behavior with GSM 06.07 test sequences.

Which standards are used with SIST ETS 300 967 E1:2003?

Standard	What it contributes
GSM 01.04 (ETR 350)	Abbreviations and acronyms used for GSM terminology
GSM 06.20 (ETS 300 969)	Half rate speech transcoding
GSM 06.21 (ETS 300 970)	Substitution and muting of lost frames
GSM 06.22 (ETS 300 971)	Comfort noise aspects
GSM 06.41 (ETS 300 972)	Discontinuous Transmission (DTX)
GSM 06.42 (ETS 300 973)	Voice Activity Detector (VAD)
GSM 06.07 (ETS 300 968)	Test sequences for the GSM half rate speech codec
ANSI 9899 (1990)	The C language used for the code

The foreword also places this document in the GSM half rate speech series alongside GSM 06.02, which covers half rate speech processing functions. That helps readers see where the ANSI-C code sits in the broader half rate speech set.

What does the SIST ETS 300 967 E1:2003 document contain?

SIST ETS 300 967 E1:2003 contains a directory structure table, program execution notes, and call graphs for the codec software. Table 1 lists the diskette contents, including source code, example data, utilities, executables, and the readme file.

Figures 1 to 7 show the function call hierarchy for decoder and encoder processing, LPC quantization, open-loop lag search, subframe processing, comfort noise, and VAD. These figures help engineers understand the software flow before testing or adapting the code.

The document also describes utility programs for text conversion, byte swapping, and encoder/decoder interface translation. That is useful when the code is installed on a target platform with different text or binary file conventions.

The attached code in clause 5 is the bit-exact ANSI-C implementation referenced by the rest of the document.

SLOVENSKI STANDARD
01-december-2003
'LJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHP±*RYRUVSROKLWURVWL±.RG$16,&]D
SROKLWURVWQLJRYRUQLNRGHNVLVWHPD*60*60UD]OLþLFD
Digital cellular telecommunications system; Half rate speech; ANSI-C code for the GSM
half rate speech codec (GSM 06.06 version 5.0.1)
Ta slovenski standard je istoveten z: ETS 300 967 Edition 1
ICS:
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN ETS 300 967
TELECOMMUNICATION May 1997
STANDARD
Source: ETSI TC-SMG Reference: DE/SMG-110606Q
ICS: 33.020
Key words: CODEC, digital cellular telecommunications system, Global System for Mobile communications
(GSM), speech, ANSI-C code
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
Digital cellular telecommunications system;
Half rate speech;
ANSI-C code for the GSM half rate speech codec
(GSM 06.06 version 5.0.1)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
Tel.: [phone] - Fax: [phone]
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1997. All rights reserved.

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ETS 300 967 (GSM 06.06 version 5.0.1): May 1997
Whilst 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 Editing and Committee Support Dept." at the address shown on the title page.

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ETS 300 967 (GSM 06.06 version 5.0.1): May 1997
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .7
3.1 Definitions .7
3.2 Abbreviations .8
4 C code structure.8
4.1 Directory structure.8
4.2 Program execution.9
4.3 Code hierarchy.9
5 ANSI-C code for the GSM half rate speech codec.16
History.17

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ETS 300 967 (GSM 06.06 version 5.0.1): May 1997
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ETS 300 967 (GSM 06.06 version 5.0.1): May 1997
Foreword
This European Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee of the European Telecommunications Standards Institute (ETSI).
A 3,5 inch diskette is attached to the back cover of this ETS, this diskette contains clause 5, the bit-exact
ANSI-C code for the GSM half rate codec.
This ETS specifies the half rate speech traffic channels for the digital cellular telecommunications system.
This ETS is part of ETSs series covering the half rate speech traffic channels as described below:
GSM 06.02 ETS 300 966: "Digital cellular telecommunications system; Half rate speech;
Half rate speech processing functions".
GSM 06.06 ETS 300 967: "Digital cellular telecommunications system; Half rate
speech; ANSI-C code for the GSM half rate speech codec".
GSM 06.07 ETS 300 968: "Digital cellular telecommunications system; Half rate speech;
Test sequences for the GSM half rate speech codec".
GSM 06.20 ETS 300 969: "Digital cellular telecommunications system; Half rate speech;
Half rate speech transcoding".
GSM 06.21 ETS 300 970: "Digital cellular telecommunications system; Half rate speech;
Substitution and muting of lost frames for half rate speech traffic channels".
GSM 06.22 ETS 300 971: "Digital cellular telecommunications system; Half rate speech;
Comfort noise aspects for half rate speech traffic channels".
GSM 06.41 ETS 300 972: "Digital cellular telecommunications system; Half rate speech;
Discontinuous Transmission (DTX) for half rate speech traffic channels".
GSM 06.42 ETS 300 973: "Digital cellular telecommunications system; Half rate speech;
Voice Activity Detector (VAD) for half rate speech traffic channels".
Transposition dates
Date of adoption: 4 April 1997
Date of latest announcement of this ETS (doa): 31 August 1997
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 28 February 1998
Date of withdrawal of any conflicting National Standard (dow): 28 February 1998

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ETS 300 967 (GSM 06.06 version 5.0.1): May 1997
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ETS 300 967 (GSM 06.06 version 5.0.1): May 1997
1 Scope
This European Telecommunication Standard (ETS) contains an electronic copy of the ANSI-C code for
the GSM half rate codec. The ANSI-C code is necessary for a bit exact implementation of the half rate
speech transcoder (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]), Discontinuous Transmission
(GSM 06.41 (ETS 300 972) [5]) and example solutions for substituting and muting of lost frames
(GSM 06.21 (ETS 300 970) [3])
2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this ETS only when incorporated in it by amendment or revision. For undated references, the
latest edition of the publication referred to applies.
[1] GSM 01.04 (ETR 350): "Digital cellular telecommunications system (Phase 2+);
Abbreviations and acronyms".
[2] GSM 06.20 (ETS 300 969): "Digital cellular telecommunications system; Half
rate speech; Half rate speech transcoding".
[3] GSM 06.21 (ETS 300 970): "Digital cellular telecommunications system; Half
rate speech; Substitution and muting of lost frame for half rate speech traffic
channels".
[4] GSM 06.22 (ETS 300 971): "Digital cellular telecommunications system; Half
rate speech; Comfort noise aspects for half rate speech traffic channels".
[5] GSM 06.41 (ETS 300 972): "Digital cellular telecommunications system; Half
rate speech; Discontinuous Transmission (DTX) for half rate speech traffic
channels".
[6] GSM 06.42 (ETS 300 973): "Digital cellular telecommunications system; Half
rate speech; Voice Activity Detector (VAD) for half rate speech traffic channels".
[7] GSM 06.07 (ETS 300 968): "Digital cellular telecommunications system; Half
rate speech; Test sequences for the GSM half rate speech codec".
[8] American National Standards Institute ANSI 9899 (1990): "Programming
Language - C (ISO)".
3 Definitions and abbreviations
3.1 Definitions
Definition of terms used in this ETS can be found in GSM 06.20 (ETS 300 969) [2], GSM 06.21
(ETS 300 970) [3], GSM 06.22 (ETS 300 971) [4], GSM 06.41 (ETS 300 972) [5] and GSM 06.42
(ETS 300 973) [6].
SIST ETS 300 96
...