SIST ETS 300 723 E2:2003
(Main)Digital cellular telecommunications system; Enhanced Full Rate (EFR) speech processing functions; General description (GSM 06.51 version 5.2.1)
- Abstract
CRs from SMG#32
- Status
- Published
- Publication Date
- 30-Nov-2003
- 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
SIST ETS 300 723 E2:2003 is the Slovenian adoption of ETS 300 723 Edition 2 from ETSI. It gives the general description of Enhanced Full Rate (EFR) speech processing functions in the digital cellular telecommunications system, and points to the detailed standards that specify each function. In practice, it helps implementers and reviewers understand how the GSM EFR speech path is organized before going into the detailed codec and control specifications.
What does SIST ETS 300 723 E2:2003 specify?
SIST ETS 300 723 E2:2003 is an introduction to the GSM EFR speech processing standards. It explains the overall speech path and identifies the companion ETSs that define transcoding, discontinuous transmission (DTX), Voice Activity Detection (VAD), comfort noise, lost frame handling, and codec homing.
The document is organized into:
- Scope
- Normative references
- Definitions and abbreviations
- General overview
- Clauses 5 to 11 covering the main speech-processing functions
- Annex A with the Change Request History
Clause 4 gives the reference configuration for the audio path between the Mobile Station (MS) and the Public Switched Telephone Network (PSTN). The later clauses explain how the EFR functions fit into that path and which companion standards define the detailed behavior.
What are the key requirements of SIST ETS 300 723 E2:2003?
SIST ETS 300 723 E2:2003 does not define the detailed algorithms itself. Its key role is to specify how the EFR speech system is partitioned and how the companion standards are used, so that implementers know which function belongs where.
EFR speech transcoding
Clause 5 explains that the encoder takes 13-bit uniform Pulse Code Modulated (PCM) input and produces coded speech for channel coding. It also states that the detailed mapping between 160-sample speech blocks and encoded blocks is defined in GSM 06.60, with the codec based on Algebraic Code Excited Linear Prediction (ACELP). For a designer, this tells you where the speech coding function begins and ends, and which document defines the exact codec behavior.
DTX and VAD
Clause 6 describes Discontinuous Transmission (DTX) as a mode where transmission is active only when needed. It identifies the DTX handlers, the VAD on the transmit side, the background-noise evaluation function, and comfort-noise generation on the receive side. Clause 7 says the VAD decides whether each 20 ms speech frame contains speech. In practice, this separates the decision to transmit from the transmitter keying itself.
Comfort noise and lost-frame handling
Clause 8 explains that comfort noise is inserted at the receiving end to avoid abrupt changes in background noise when speech pauses occur. Clause 9 says lost speech frames are substituted using prediction for isolated losses, while several consecutive lost frames are handled with muting. For operations and quality assurance, this means the standard expects the receiver to mask radio errors rather than output silence or raw gaps.
Codec homing and test support
Clause 10 defines homing behavior for the transcoder, VAD, DTX system, and comfort-noise functions. It ties bit exact behavior to known input sequences and supports type approval of terminal and infrastructure equipment, as well as remote testing and maintenance. That matters because it gives a repeatable reset state for conformance checks.
Alternative implementation
Clause 11 allows an alternative implementation based on the Adaptive Multi Rate (AMR) 12.2 kbit/s mode. The document says this alternative must still use the GSM DTX transmission format and comfort-noise generation, and it notes an added 5 ms look-ahead delay. This clause is important when choosing between a native EFR codec and a functionally equivalent AMR-based implementation.
What terms does SIST ETS 300 723 E2:2003 define?
- ACELP - Algebraic Code Excited Linear Prediction, the speech coding method used for EFR.
- BFI - Bad Frame Indication, a flag related to received frame quality.
- DTX - Discontinuous Transmission, a mode that switches transmission off during silence.
- SID - Silence Descriptor, the frame used to carry comfort-noise parameters.
- SP - Speech flag, which indicates whether transmitted information is speech or SID information.
- TAF - Time Alignment Flag, which marks the position of a SID frame within the SACCH multiframe.
- VAD - Voice Activity Detector, the function that decides whether a frame contains speech.
Who uses SIST ETS 300 723 E2:2003?
SIST ETS 300 723 E2:2003 is used by GSM speech-codec implementers, mobile terminal designers, and infrastructure equipment engineers. It is also relevant to test labs, approval bodies, and maintenance teams that need to verify codec state behavior, DTX operation, and interoperability. Quality managers and buyers use it to identify which companion standards define the actual algorithms and which parts only provide the system overview.
What changed in SIST ETS 300 723 E2:2003 from the previous edition?
The document history and Annex A show an update from version 5.1.2 to version 5.2.1 for publication. Annex A also records the addition of the alternative EFR implementation using the AMR 12.2 mode. The foreword states that this ETS corresponds to GSM technical specification GSM 06.51, version 5.1.2.
Which standards are used with SIST ETS 300 723 E2:2003?
- GSM 01.04 (ETR 100) - provides abbreviations and acronyms used when a term is not defined here.
- GSM 03.50 (ETS 300 540) - covers transmission planning aspects of the speech service and the audio parts of the speech path.
- GSM 05.03 (ETS 300 575) - defines channel coding for the encoded speech blocks.
- GSM 06.53 (ETS 300 724) - gives the ANSI-C code for the EFR speech codec.
- GSM 06.54 (ETS 300 725) - provides the digital test sequences used for compliance checks.
- GSM 06.60 (ETS 300 726) - defines EFR speech transcoding.
- GSM 06.61 (ETS 300 727) - defines substitution and muting of lost frames.
- GSM 06.62 (ETS 300 728) - defines comfort noise aspects.
- GSM 06.81 (ETS 300 729) - defines DTX for EFR speech traffic channels.
- GSM 06.82 (ETS 300 730) - defines VAD for EFR speech traffic channels.
What does the SIST ETS 300 723 E2:2003 document contain?
The document contains a system overview, a reference configuration figure, and a clause-by-clause map of the EFR speech functions. It describes the speech path from audio input/output in the MS to the PSTN interface, including PCM formats, frame types, flags, and the role of the radio subsystem. It also explains how bit exact behavior, homing frames, and digital test sequences support conformance testing and approval.
Annex A provides the Change Request History, which is useful for tracking how the publication was updated.
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Frequently Asked Questions
SIST ETS 300 723 E2:2003 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Digital cellular telecommunications system; Enhanced Full Rate (EFR) speech processing functions; General description (GSM 06.51 version 5.2.1)". This standard covers: CRs from SMG#32
CRs from SMG#32
SIST ETS 300 723 E2:2003 is classified under the following ICS (International Classification for Standards) categories: 33.070.50 - Global System for Mobile Communication (GSM). The ICS classification helps identify the subject area and facilitates finding related standards.
SIST ETS 300 723 E2:2003 is associated with the following European legislation: Standardization Mandates: T-172. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
SIST ETS 300 723 E2:2003 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2003
'LJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHP±)XQNFLMH]DREGHODYRL]EROMãDQHJD
JRYRUDVSROQRKLWURVWMR ()5 ±6SORãQLRSLV *60UD]OLþLFD
Digital cellular telecommunications system; Enhanced Full Rate (EFR) speech
processing functions; General description (GSM 06.51 version 5.2.1)
Ta slovenski standard je istoveten z: ETS 300 723 Edition 2
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 300 723
TELECOMMUNICATION December 2000
STANDARD Second Edition
Source: ETSI TC-SMG Reference: RE/SMG-110651
ICS: 33.020
Key words: EFR, digital cellular telecommunications system, Global System for Mobile communications
(GSM), speech
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
Digital cellular telecommunications system;
Enhanced Full Rate (EFR) speech processing functions;
General description
(GSM 06.51 version 5.2.1)
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
Internet: secretariat@etsi.fr - http://www.etsi.org
Tel.: +33 4 92 94 42 00 - Fax: +33 4 93 65 47 16
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 2000. All rights reserved.
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ETS 300 723: December 2000 (GSM 06.51 version 5.2.1)
Whilst every care has been taken in the preparation and publication of the present document, errors in
content, typographical or otherwise, may occur. If you have comments concerning its accuracy, please
write to "ETSI Standards Making Support Dept." at the address shown on the title page.
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ETS 300 723: December 2000 (GSM 06.51 version 5.2.1)
Contents
Intellectual Property Rights.5
Foreword.5
1 Scope .7
2 Normative references .7
3 Definitions and abbreviations .7
3.1 Definitions .7
3.2 Abbreviations .8
4 General.8
5 Enhanced Full Rate speech channel transcoding.10
6 Enhanced Full Rate speech channel discontinuous transmission (DTX) .10
7 Enhanced Full Rate speech channel Voice Activity Detection (VAD).11
8 Enhanced Full Rate speech channel comfort noise insertion .11
9 Enhanced Full Rate speech channel lost speech frame substitution and muting.11
10 Enhanced Full Rate codec homing .12
11 Alternative Enhanced Full Rate implementation using the Adaptive Multi Rate 12.2 kbit/s mode .12
Annex A (informative): Change Request History .13
History.14
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ETS 300 723: December 2000 (GSM 06.51 version 5.2.1)
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ETS 300 723: December 2000 (GSM 06.51 version 5.2.1)
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://www.etsi.org/ipr).
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 Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee of the European Telecommunications Standards Institute (ETSI).
The present document introduces the Enhanced Full Rate (EFR) speech traffic channels within the digital
cellular telecommunications system.
The present document corresponds to GSM technical specification, GSM 06.51, version 5.1.2.
Transposition dates
Date of adoption of this ETS: 1 December 2000
Date of latest announcement of this ETS (doa):
31 March 2001
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 30 September 2001
Date of withdrawal of any conflicting National Standard (dow): 30 September 2001
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ETS 300 723: December 2000 (GSM 06.51 version 5.2.1)
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ETS 300 723: December 2000 (GSM 06.51 version 5.2.1)
1 Scope
This European Telecommunication Standard (ETS) is an introduction to GSM 06.60 (ETS 300 726) [6],
GSM 06.61 (ETS 300 727) [7], GSM 06.62 (ETS 300 728) [8], GSM 06.81 (ETS 300 729) [9] and
GSM 06.82 (ETS 300 730) [10] ETSs dealing with the speech processing functions in the Enhanced Full
Rate channel of the GSM system. A general overview of the speech processing functions is given, with
reference to the ETSs where each function is specified in detail.
2 Normative references
The present document 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 the present document 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): "Digital cellular telecommunications system (Phase 2);
Abbreviations and acronyms".
[2] GSM 03.50 (ETS 300 540): "Digital cellular telecommunications system
(Phase 2); Transmission planning aspects of the speech service in the GSM
Public Land Mobile Network (PLMN) system".
[3] GSM 05.03 (ETS 300 575): "Digital cellular telecommunications system
(Phase 2); Channel coding".
[4] GSM 06.53 (ETS 300 724): "Digital cellular telecommunications system;
ANSI-C code for the GSM Enhanced Full Rate (EFR) speech codec".
[5] GSM 06.54 (ETS 300 725): "Digital cellular telecommunications system; Test
vectors for the GSM Enhanced Full Rate (EFR) speech codec".
[6] GSM 06.60 (ETS 300 726): "Digital cellular telecommunications system;
Enhanced Full Rate (EFR) speech transcoding".
[7] GSM 06.61 (ETS 300 727): "Digital cellular telecommunications system;
Substitution and muting of lost frame for Enhanced Full Rate (EFR) speech
traffic channels".
[8] GSM 06.62 (ETS 300 728): "Digital cellular telecommunications system;
Comfort noise aspects for Enhanced Full Rate (EFR) speech traffic channels".
[9] GSM 06.81 (ETS 300 729): "Digital cellular telecommunications system;
Discontinuous transmission (DTX) for Enhanced Full Rate (EFR) speech traffic
channels".
[10] GSM 06.82 (ETS 300 730): "Digital cellular telecommunications system; Voice
Activity Detector (VAD) for Enhanced Full Rate (EFR) speech traffic channels".
3 Definitions and abbreviations
3.1 Definitions
Definition of terms used in the present document can be found in GSM 06.60 (ETS 300 726) [6],
GSM 06.61 (ETS 300 727) [7], GSM 06.62 (ETS 300 728) [8], GSM 06.81 (ETS 300 729) [9] and
GSM 06.82 (ETS 300 730) [10].
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ETS 300 723: December 2000 (GSM 06.51 version 5.2.1)
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACELP Algebraic Code Excited Linear Prediction
BFI Bad Frame Indication
BSS Base Station System
CCITT Comité Consultatif International Télégraphique et Téléphonique
DTX Discontinuous Transmission
ETS European Telecommunication Standard
GSM Global System for Mobile communications
MS Mobile Station
PCM Pulse Code Modulated
PLMN Public Land Mobile Network
PSTN Public Switched Telephone Network
RF Radio Frequency
RSS Radio SubSystem
RX Receive
SACCH Slow Associated Control CHannel
SID SIlence Descriptor
SP flag SPeech flag
TAF Time Alignment Flag
TX Transmit
For abbreviations not given in this clause, see GSM 01.04 (ETR 100) [1].
4 General
Figure 1 presents a reference configuration where the various speech processing functions are identified.
In this figure, the relevant ETSs for each function are also indicated.
In figure 1, the audio parts including analogue to digital and digital to analogue conversion are included,
to show the complete speech path between the audio input/output in the Mobile Station (MS) and the
digital interface of the PSTN. The detailed specification of the audio parts are contained in GSM 03.50
(ETS 300 540) [2]. These aspects are only considered to the extent that the performance of the audio
parts affect the performance of the speech transcoder.
An alternative and fully interoperable implementation using as a basis the 12.2 kbit/s mode of the
Adaptive Multi Rate speech coder is described in clause 11.
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