SIST ETS 300 968 E2:2003

SLOVENSKI STANDARD
SIST ETS 300 968 E2:2003
01-december-2003
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Digital cellular telecommunications system (Phase 2+) (GSM); Half rate speech; Test
sequences for the GSM half rate speech codec (GSM 06.07 version 5.2.1)
Ta slovenski standard je istoveten z: ETS 300 968 Edition 2
ICS:
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
SIST ETS 300 968 E2:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 968 E2:2003

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SIST ETS 300 968 E2:2003
EUROPEAN ETS 300 968
TELECOMMUNICATION April 1998
STANDARD Second Edition
Source: SMG Reference: RE/SMG-110607QR1
ICS: 33.020
Key words: CODEC, digital cellular telecommunications system, Global System for Mobile communications
(GSM), speech, test sequence
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
Digital cellular telecommunications system (Phase 2+);
Half rate speech;
Test sequences for the GSM half rate speech codec
(GSM 06.07 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.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 1998. All rights reserved.

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ETS 300 968 (GSM 06.07 version 5.2.1): April 1998
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 300 968 (GSM 06.07 version 5.2.1): April 1998
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 Test sequence format .8
5.1 File format.8
5.2 Codec homing.8
6 Speech codec test sequences .9
6.1 Codec configuration.9
6.2 Speech codec test sequences.9
6.2.1 Speech encoder test sequences.10
6.2.2 Speech decoder test sequences.10
6.2.3 Codec homing sequence.10
7 DTX test sequences.11
7.1 Codec configuration.11
7.2 DTX test sequences .11
7.2.1 Predictor values computation.11
7.2.2 Spectral comparison.11
7.2.3 Threshold adaptation.12
7.2.4 Periodicity detection .12
7.2.5 Tone detection.12
7.2.6 Safety and initialization.12
7.2.7 Comfort noise test sequence .12
7.2.8 Real speech and tones.12
8 Sequences for finding the 20 ms framing of the GSM half rate speech encoder .13
8.1 Bit synchronization.13
8.2 Frame synchronization.13
8.3 Formats and sizes of the synchronization sequences .14
9 Trau Testing with 8 Bit A- and μ-law PCM Test Sequences .15
10 Test sequences for the GSM half rate speech codec .16
History.17

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ETS 300 968 (GSM 06.07 version 5.2.1): April 1998
Foreword
This second edition European Telecommunication Standard (ETS) has been produced by the Special
Mobile Group (SMG) of the European Telecommunications Standards Institute (ETSI).
Five 3,5 inch diskettes are attached to the back cover of this ETS, the diskettes contain test sequences for
a bit exact implementation of the half rate speech transcoder.
The diskettes contain compressed files and are labelled as follows:
Diskette 1/5 ETS 300 968 clause 10: Test sequences for the GSM half rate speech codec;
Disks 2 and 4 (GSM 06.07).
Diskette 2/5 ETS 300 968 clause 10: Test sequences for the GSM half rate speech codec;
Disks 1, 3 and 5 (GSM 06.07).
Diskette 3/5 ETS 300 968 clause 10: Test sequences for the GSM half rate speech codec;
Disks 6 and 10 (GSM 06.07).
Diskette 4/5 ETS 300 968 clause 10: Test sequences for the GSM half rate speech codec;
Disks 7 and 11 (GSM 06.07).
Diskette 5/5 ETS 300 968 clause 10: Test sequences for the GSM half rate speech codec;
Disks 8 and 9 (GSM 06.07).
This ETS specifies the half rate speech traffic channels for the Digital cellular telecommunications system.
This ETS specifies the digital test sequences for the GSM half rate speech codec for the digital cellular
telecommunications system. This ETS, is part of an ETSs series covering the half rate speech traffic
channels as described below:
GSM 06.02 ETS 300 966: "Digital cellular telecommunications system (Phase 2+); Half rate
speech; Half rate speech processing functions".
GSM 06.06 ETS 300 967: "Digital cellular telecommunications system (Phase 2+); Half rate
speech; ANSI-C code for the GSM half rate speech codec".
GSM 06.07 ETS 300 968: "Digital cellular telecommunications system (Phase 2+); Half
rate speech; Test sequences for the GSM half rate speech codec".
GSM 06.20 ETS 300 969: "Digital cellular telecommunications system (Phase 2+); Half rate
speech; Half rate speech transcoding".
GSM 06.21 ETS 300 970: "Digital cellular telecommunications system (Phase 2+); 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 (Phase 2+); Half rate
speech; Comfort noise aspects for half rate speech traffic channels".
GSM 06.41 ETS 300 972: "Digital cellular telecommunications system (Phase 2+); Half rate
speech; Discontinuous Transmission (DTX) for half rate speech traffic
channels".
GSM 06.42 ETS 300 973: "Digital cellular telecommunications system (Phase 2+); Half rate
speech; Voice Activity Detector (VAD) for half rate speech traffic channels".

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Transposition dates
Date of adoption of this ETS: 3 April 1998
Date of latest announcement of this ETS (doa): 30 June 1998
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 December 1998
Date of withdrawal of any conflicting National Standard (dow): 31 December 1998

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ETS 300 968 (GSM 06.07 version 5.2.1): April 1998
1 Scope
This European Telecommunication Standard (ETS) specifies the digital test sequences for the GSM half
rate speech codec. These sequences test 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]) and the discontinuous transmission (GSM 06.41
(ETS 300 972) [5]).
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
(Phase 2+); Half rate speech; Half rate speech transcoding".
[3] GSM 06.21 (ETS 300 970): "Digital cellular telecommunications system
(Phase 2+); 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
(Phase 2+); Half rate speech; Comfort noise aspects for half rate speech traffic
channels".
[5] GSM 06.41 (ETS 300 972): "Digital cellular telecommunications system
(Phase 2+); Half rate speech; Discontinuous Transmission (DTX) for half rate
speech traffic channels".
[6] GSM 06.42 (ETS 300 973): "Digital cellular telecommunications system
(Phase 2+); Half rate speech; Voice Activity Detector (VAD) for half rate speech
traffic channels".
[7] GSM 06.06 (ETS 300 967): "Digital cellular telecommunications system
(Phase 2+); Half rate speech; ANSI-C code for the GSM half rate speech
codec".
[8] GSM 06.02 (ETS 300 966): "Digital cellular telecommunications system
(Phase 2+); Half rate speech; Half rate speech coding functions".
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].
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply:
ETS European Telecommunication Standard
GSM Global System for Mobile communications
For abbreviations not given in this subclause, see GSM 01.04 (ETR 350) [1].

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4 General
Digital test sequences are necessary to test 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]) and the discontinuous transmission (GSM 06.41
(ETS 300 972) [5]).
The test sequences may also be used to verify installations of the ANSI C code in GSM 06.06
(ETS 300 967) [7].
Clause 5 describes the format of the files which contain the digital test sequences. Clause 6 describes the
test sequences for the speech transcoder. Clause 7 describes the test sequences for the VAD, comfort
noise and discontinuous transmission.
Clause 8 describes the method by which synchronization is obtained between the test sequences and the
speech codec under test.
Clause 9 describes the optional acceptance testing of the speech encoder and decoder in the TRAU by
means of 8 bit A- or m-law compressed test sequences on the A-Interface.
Electronic copies of the digital test sequences are provided as clause 10, these digital test sequences are
contained in the five 3.5 inch diskettes attached to the back cover of this ETS 300 968.
5 Test sequence format
This clause provides information on the format of the digital test sequences for the GSM 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]) and the discontinuous transmission (GSM 06.41
(ETS 300 972) [5]).
5.1 File format
The test sequence files are provided on 5 floppy disks (3,5 inch) which are formatted according to the high
1) 2)
capacity (1,44 Mb) specifications for MS-DOS IBM -PC/AT compatible computers.
Following decompression, by execution of the 11 "disk*.exe" files, four types of file are provided:
- Files for input to the GSM half rate speech encoder: *.INP
- Files for comparison with the encoder output: *.COD
- Files for input to the GSM half rate speech decoder: *.DEC
- Files for comparison with the decoder output: *.OUT
Tables 1, 2, 3 and 4 define the formats of the four types of file. Each parameter in these tables is
contained in a 16 bit word except for the samples of the 8 bit PCM test sequences, which are contained in
an 8 bit word each. The left or right justification is indicated in the tables. The size and location of speech
parameters in the encoder output (*.COD) and decoder input files (*.DEC) are described in GSM 06.20
(ETS 300 969) [2].
5.2 Codec homing
Each *.INP file includes two homing frames at the start of the test sequence. The function of these frames
is to reset the speech encoder state variables to their initial value. In the case of a correct installation of
the ANSI-C simulation (GSM 06.06 (ETS 300 967) [7]), all speech encoder output frames shall be
identical to the corresponding frame in the *.COD file. In the case of a correct hardware implementation
undergoing type approval, the first speech encoder output frame is undefined and need not be identical to

1)
This is a trademark of Microsoft.
2)
This is a trademark of International Business Machines

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ETS 300 968 (GSM 06.07 version 5.2.1): April 1998
the first frame in the *.COD file, but all remaining speech encoder output frames shall be identical to the
corresponding frames in the *.COD file.
Each *.DEC file includes two homing frames at the start of the test sequence. The function of these
frames is to reset the speech decoder state variables to their initial value. In the case of a correct
installation of the ANSI-C simulation (GSM 06.06 (ETS 300 967) [7]), all speech decoder output frames
shall be identical to the corresponding frame in the *.OUT file. In the case of a correct hardware
implementation undergoing type approval, the first speech decoder output frame is undefined and need
not be identical to first frame in the *.OUT file, but all remaining speech decoder output frames shall be
identical to the corresponding frames in the *.OUT file.
Table 1: Encoder input sequence (*.INP) format
Name Description No. of bits Justification
s(n) Encoder input signal 13 Left
Table 2: Encoder output sequence (*.COD) format
Name Description No. of words Justification
Speech Speech parameters to the channel 18 Right
encoder
Additional information
VAD Voice activity detection flag 1 Right
SP SP flag 1 Right
Table 3: Decoder input sequence (*.DEC) format
Name Description No. of Justification
bits/words
Speech parameters Speech parameters to the channel 18 words Right
encoder
BFI flag Bad Frame Indicator 1 bit / 1 word Right
UFI flag Unreliable Frame Indicator 1 bit / 1 word Right
SID flag SIlence Descriptor 2 bits / 1 word Right
TAF flag Time Alignment Flag 1 bit / 1 word Right
Table 4: Decoder output sequence (*.OUT) f
...