SIST ETS 300 581-3 E1:2003

• Abstract:

  .

• 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 300 581-3 ed.1 (1995-12) - European digital cellular telecommunications system; Half rate speech; Part 3: Substitution and muting of lost frames for half rate speech traffic channels (GSM 06.21)

SIST ETS 300 581-3 E1:2003 is the Slovene adoption of ETS 300 581-3 Edition 1, published by SIST from an ETSI European Telecommunication Standard. It specifies how the GSM receive side handles lost or unreliable speech and SID frames on half rate speech traffic channels, so base station and mobile station implementations can conceal frame loss in a consistent way. The document is part 3 of the GSM half rate speech series and is identified with GSM 06.21.

What does SIST ETS 300 581-3 E1:2003 specify?

SIST ETS 300 581-3 E1:2003 specifies a frame substitution and muting procedure for the Receive (RX) Discontinuous Transmission (DTX) handler when speech or SIlence Descriptor (SID) frames are lost or judged unreliable. The procedure is mandatory for GSM Base Station Systems (BSS) and Mobile Stations (MS) that support the half rate speech traffic channel.

The document is organized into a foreword, six clauses, and a history section:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Definitions and abbreviations
• Clause 4 - General
• Clause 5 - Requirements
• Clause 6 - Example solutions

Clause 4 explains the flags that drive the decoder behavior, and Clause 6 gives worked implementation approaches.

What are the key requirements of SIST ETS 300 581-3 E1:2003?

SIST ETS 300 581-3 E1:2003 sets out how the speech decoder should react when the Radio Sub System (RSS) marks a frame as lost or unreliable. In practice, the document separates “probably wrong” frames from clearly lost frames and gives different concealment behavior for each case.

Frame status and error handling

• A set Bad Frame Indication (BFI) flag means a speech or SID frame is lost.
• A set Unreliable Frame Indication (UFI) flag with a cleared BFI flag means the frame may be erroneous.
• For unreliable frames, the decoder shall use extra error detection based on frame parameters and output signal properties.
• If an unreliable frame is judged unusable, the BFI flag is set and substitution and muting are applied.

This matters because the decoder is not allowed to trust every received frame equally; it must screen questionable frames before they reach the speech output.

Concealment for usable unreliable frames

• If an unreliable frame is still considered usable, the decoder shall compare its output signal with previous valid frames.
• If the difference is too large, the output signal shall be modified to limit the change.

This keeps abrupt artifacts out of the audio when a frame is suspicious but not completely rejected.

Lost speech and SID frame handling

• For the first and second lost speech frame, the decoder shall partly or completely substitute the last valid speech frame, and it shall not mute directly.
• For subsequent lost speech frames, the output shall be muted gradually and reach silence after at most 80 ms.
• For the first and second lost SID frame, the decoder shall substitute the last good SID frame, and it shall not mute directly.
• For subsequent lost SID frames, the output shall be muted gradually and reach silence after at most 320 ms.

In practice, this means the first losses are concealed by repetition, while longer runs of loss are turned into a controlled fade-out instead of distorted speech.

Implementation guidance

• Clause 6 provides example solutions for error detection, output signal concealment, and frame substitution and muting.
• The examples are described in terms of decoder behavior and are linked to C code published in GSM 06.06.

What terms does SIST ETS 300 581-3 E1:2003 define?

SIST ETS 300 581-3 E1:2003 uses a small set of core terms and abbreviations that shape how the procedure is read:

• BFI (Bad Frame Indication) - a flag that marks a frame as lost.
• UFI (Unreliable Frame Indication) - a flag that marks a frame as probably erroneous.
• SID (SIlence Descriptor) - a frame type used when speech is not active.
• DTX (Discontinuous Transmission) - the receive/transmit handling mode associated with silence periods.
• RX (Receive) - the receive-side handling path.
• RSS (Radio Sub System) - the radio part that signals lost or unreliable frames.
• LPC (Linear Predictive Coding) - the coding approach referenced in the decoder context.

Who uses SIST ETS 300 581-3 E1:2003?

SIST ETS 300 581-3 E1:2003 is used by GSM BSS and MS implementers who need to handle lost speech or SID frames in half rate speech traffic channels. It is also relevant to speech codec developers, radio subsystem engineers, and verification teams testing how a decoder behaves under frame loss and poor channel conditions.

For buyers and quality managers, the standard is the reference that shows whether an implementation includes the required concealment behavior for half rate speech handling.

Which standards are used with SIST ETS 300 581-3 E1:2003?

Standard	What it contributes
GSM 01.04 (ETR 100)	Abbreviations and acronyms not defined in this part.
GSM 05.03 (ETS 300 575)	Channel coding reference used for terminology and context.
GSM 06.20 (ETS 300 581-2)	Half rate speech transcoding and shared definitions.
GSM 06.41 (ETS 300 581-5)	Discontinuous Transmission (DTX) context and definitions.
GSM 06.06 (ETS 300 581-7)	ANSI-C code for the example solutions.
GSM 06.02 (ETS 300 581-1)	Half rate speech processing functions in the same series.
GSM 06.22 (ETS 300 581-4)	Comfort noise aspects for half rate speech traffic channels.
GSM 06.42 (ETS 300 581-6)	Voice Activity Detection (VAD) for half rate speech traffic channels.
GSM 06.07 (ETS 300 581-8)	Test vectors for the GSM half rate speech codec.

What does the SIST ETS 300 581-3 E1:2003 document contain?

SIST ETS 300 581-3 E1:2003 contains the rule set for reacting to BFI and UFI conditions, plus example strategies that show how a decoder can substitute frames and fade the output in a controlled way. The example material includes an 8-state approach for lost speech frames and a repeated-frame approach for lost SID frames, both described in terms of decoder parameters such as R0, MODE, INT_LPC, LPC coefficients, GSP0 parameters, and codevectors.

The document also includes a history section that records the public enquiry, vote, and first edition process for the ETS.

SLOVENSKI STANDARD
01-december-2003
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European digital cellular telecommunications system; Half rate speech; Part 3:
Substitution and muting of lost frames for half rate speech traffic channels (GSM 06.21)
Ta slovenski standard je istoveten z: ETS 300 581-3 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 300 581-3
TELECOMMUNICATION November 1995
STANDARD
Source: ETSI TC-SMG Reference: DE/SMG-020621
ICS: 33.060.50
European digital cellular telecommunications system, Global System for Mobile communications
Key words:
(GSM)
European digital cellular telecommunications system;
Half rate speech
Part 3: Substitution and muting of lost frames for half rate
speech traffic channels
(GSM 06.21)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - [e-mail]
X.400: Internet:
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 1995. All rights reserved.

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ETS 300 581-3: November 1995 (GSM 06.21 version 4.0.2)
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 300 581-3: November 1995 (GSM 06.21 version 4.0.2)
Contents
Foreword .5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .7
3.1 Definitions .7
3.2 Abbreviations .7
4 General.8
5 Requirements.8
5.1 Error detection and concealment in case of unreliable speech or SID frames.8
5.1.1 Error detection.8
5.1.2 Output signal concealment.8
5.2 Frame substitution and muting in case of lost speech or SID frames .8
5.2.1 First and second lost speech frame .8
5.2.2 Subsequent lost speech frames.8
5.2.3 First and second lost SID frame.8
5.2.4 Subsequent lost SID frames .9
6 Example solutions .9
6.1 Example solution for error detection in case of unreliable frames.9
6.2 Example solution for output signal concealment in case of unreliable frames .9
6.3 Example solution for substitution and muting of lost speech frames.9
6.4 Example solution for substitution and muting of lost SID frames .10
History.11

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ETS 300 581-3: November 1995 (GSM 06.21 version 4.0.2)
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ETS 300 581-3: November 1995 (GSM 06.21 version 4.0.2)
Foreword
This European Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee of the European Telecommunications Standards Institute (ETSI).
This ETS specifies the half rate speech traffic channels for the European digital cellular
telecommunications system. This ETS corresponds to GSM technical specification, GSM 06.21, version
4.0.2 and is part 3 of a multi-part ETS covering the half rate speech traffic channels as described below:
GSM 06.02 ETS 300 581-1: "European digital cellular telecommunications system; Half rate
speech Part 1: Half rate speech processing functions".
GSM 06.20 ETS 300 581-2: "European digital cellular telecommunications system; Half rate
speech Part 2: Half rate speech transcoding".
GSM 06.21 ETS 300 581-3: "European digital cellular telecommunications system;
Half rate speech Part 3: Substitution and muting of lost frames for half rate
speech traffic channels".
GSM 06.22 ETS 300 581-4: "European digital cellular telecommunications system; Half rate
speech Part 4: Comfort noise aspects for half rate speech traffic channels".
GSM 06.41 ETS 300 581-5: "European digital cellular telecommunications system; Half rate
speech Part 5: Discontinuous Transmission (DTX) for half rate speech traffic
channels".
GSM 06.42 ETS 300 581-6: "European digital cellular telecommunications system; Half rate
speech Part 6: Voice Activity Detection (VAD) for half rate speech traffic
channels".
GSM 06.06 ETS 300 581-7: "European digital cellular telecommunications system; Half rate
speech Part 7: ANSI-C code for the GSM half rate speech codec".
GSM 06.07 ETS 300 581-8: "European digital cellular telecommunications system; Half rate
speech Part 8: Test vectors for the GSM half rate speech codec".
NOTE: TC-SMG has produced documents which give the technical specifications for the
implementation of the European digital cellular telecommunications system.
Historically, these documents have been identified as GSM Technical Specifications
(GSM-TS). These TSs may have subsequently become Interim European
Telecommunication Standards (I-ETSs), (Phase 1), or European Telecommunication
Standards (ETSs), (Phase 2), whilst others may become ETSI Technical Reports
(ETRs).
Transposition dates
Date of adoption of this ETS: 27 October 1995
Date of latest announcement of this ETS (doa): 28 February 1996
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 August 1996
Date of withdrawal of any conflicting National Standard (dow): 31 August 1996

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ETS 300 581-3: November 1995 (GSM 06.21 version 4.0.2)
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ETS 300 581-3: November 1995 (GSM 06.21 version 4.0.2)
1 Scope
This European Telecommunication Standard (ETS) defines a frame substitution and muting procedure
which shall be used by the Receive (RX) Discontinuous Transmission (DTX) handler when one or more
lost or unreliable speech or SIlence Descriptor (SID) frames are received from the Radio Sub System
(RSS).
The requirements of this ETS are mandatory for implementation in all GSM Base Station Systems (BSS)s
and Mobile Stations (MS)s capable of supporting the half rate speech traffic channel.
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 100): "European digital cellular telecommunication system
(Phase 2); Abbreviations and acronyms".
[2] GSM 05.03 (ETS 300 575): "European digital cellular telecommunications
system (Phase 2); Channel coding".
[3] GSM 06.20 (ETS 300 581-2): "European digital cellular telecommunications
system; Half rate speech Part 2: Half rate speech transcoding".
[4] GSM 06.41 (ETS 300 581-5): "European digital cellular telecommunications
system; Half rate speech Part 5: Discontinuous transmission (DTX) for half r
...