ETSI ETS 300 609-3 ed.1 (1999-01)

Digital cellular telecommunications system (Phase 2) (GSM); Base Station System (BSS) equipment specification; Part 3: Transcoder aspects (GSM 11.24 version 4.3.1)

DE/SMG-081124P

Digitalni celični telekomunikacijski sistem (faza 2) ¬– Specifikacija opreme sistema baznih postaj (BSS) – 3. del: Vidiki prekodirnika (GSM 11.24, različica 4.3.1)

General Information

• Status: Published
• Publication Date: 19-Jan-1999
• Technical Committee: SMG 8 - Base Station System (BSS) Testing (GSM 11.20)
• Current Stage: 12 - Completion
• Due Date: 05-Feb-1999
• Completion Date: 20-Jan-1999
• Ref Project: SIST ETS 300 609-3 E1:2003 - Digital cellular telecommunications system (Phase 2) (GSM); Base Station System (BSS) equipment specification; Part 3: Transcoder aspects (GSM 11.24 version 4.3.1)

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2003
'LJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHPID]D¤±6SHFLILNDFLMDRSUHPHVLVWHPD
ED]QLKSRVWDM%66±GHO9LGLNLSUHNRGLUQLND*60UD]OLþLFD
Digital cellular telecommunications system (Phase 2) (GSM); Base Station System (BSS)
equipment specification; Part 3: Transcoder aspects (GSM 11.24 version 4.3.1)
Ta slovenski standard je istoveten z: ETS 300 609-3 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 300 609-3
TELECOMMUNICATION January 1999
STANDARD
Source: SMG Reference: DE/SMG-081124P
ICS: 33.020
Key words: Digital cellular telecommunications system, Global System for Mobile Communications (GSM)
R
GLOBAL SYSTEM FOR
MOBILE COMMUNICATIONS
Digital cellular telecommunications system (Phase 2);
Base Station System (BSS) equipment specification;
Part 3: Transcoder aspects
(GSM 11.24 version 4.3.1)
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: [e-mail] - http://www.etsi.org
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 1999. All rights reserved.

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
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 Standards Making Support Dept." at the address shown on the title page.

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
Contents
Intellectual Property Rights.5
Foreword .5
Introduction.5
1 Scope .7
2 Normative references.7
3 Definitions and abbreviations .9
3.1 Definitions .9
3.2 Abbreviations .9
4 Transcoding and rate adaption.10
4.1 Transcoder test points .10
4.1.1 External interfaces.10
4.1.1.1 Test signals applied to the antenna connector .10
4.1.2 Internal test points and interfaces .11
5 Test descriptions for speech related transcoding function.17
5.1 Test descriptions for full rate speech related transcoding functions.17
5.1.1 Uplink tests.17
5.1.1.1 Uplink speech transcoding - 13 kbit/s to 104 kbit/s
conversion .17
5.1.1.2 Uplink speech transcoding - 13 kbit/s to 16 kbit/s
conversion .18
5.1.1.3 Uplink speech transcoding - 16 kbit/s to 104 kbit/s
conversion .18
5.1.1.4 Uplink speech transcoding - 104 kbit/s to 64 kbit/s
conversion .19
5.1.1.5 Uplink Speech Decoder - 13 kbit/s to 104 kbit/s
conversion with DTX.19
5.1.1.6 Uplink Speech Decoder - 13 kbit/s to 16 kbit/s conversion
with DTX .23
5.1.1.7 Uplink Speech Decoder - 16 kbit/s to 104 kbit/s
conversion with DTX.24
5.1.2 Downlink tests .26
5.1.2.1 Downlink speech transcoding - 64 kbit/s to 104 kbit/s
conversion .26
5.1.2.2 Downlink speech transcoding - 104 kbit/s to 13 kbit/s
conversion .26
5.1.2.3 Downlink speech transcoding - 104 kbit/s to 16 kbit/s
conversion .27
5.1.2.4 Downlink speech transcoding - 16 kbit/s to 13 kbit/s
conversion .28
5.1.2.5 Downlink transmitter DTX/VAD functions - 104 kbit/s to
13 kbit/s level conversion with DTX.28
5.1.2.6 Downlink transmitter DTX/VAD functions - 104 kbit/s to
16 kbit/s conversion process .29
5.1.2.7 Downlink transmitter DTX/VAD functions - 16 kbit/s to 13
kbit/s conversion.30
5.2 Test descriptions for half rate speech related transcoding functions.31
5.3 Test descriptions for enhanced full rate speech related transcoding functions.31
5.4 Alternative use of the 64 kbit/s A-Interface for full, half and enhanced full rate speech
transcoding tests.32

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
6 Test descriptions for full rate data rate adaption functions. 32
6.1 Uplink rate adaptation data tests. 33
6.1.1 Uplink rate adaptation, transparent data: radio rate to 64 kbit/s level. 33
6.1.2 Uplink rate adaptation, transparent data - radio rate to 16kbit/s conversion 34
6.1.3 Uplink rate adaption, transparent data: 16 kbit/s to 64 kbit/s. 35
6.1.4 Uplink rate adaptation, non-transparent data: radio rates to 64 kbit/s. 36
6.1.5 Uplink rate adaptation, non-transparent data: radio rate to 16kbit/s
conversion . 37
6.1.6 Uplink rate adaption, non-transparent data: 16 kbit/s to 64 kbit/s . 38
6.2 Downlink rate adaptation data tests . 39
6.2.1 Downlink rate adaptation, transparent data : 64 kbit/s to radio rates . 39
6.2.2 Downlink rate adaptation, transparent data - 64 kbit/s to 16 kbit/s
conversion . 40
6.2.3 Downlink rate adaptation, transparent data: 16 kbit/s to radio rate . 41
6.2.4 Downlink rate adaptation, non-transparent data: 64 kbit/s to radio rates
conversion . 41
6.2.5 Downlink rate adaptation, non-transparent data - 64 kbit/s to 16 kbit/s
conversion . 42
6.2.6 Downlink rate adaptation, non-transparent data: 16 kbit/s to radio rate . 43
Annex A (informative): Change history. 45
History. 46

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
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 SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially
Essential, IPRs notified to ETSI in respect of ETSI standards", which is available free of charge 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 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).
This European Telecommunication Standard (ETS) describes the tests for transcoding functions within
the digital cellular telecommunications system (Phase 2).
The contents of this ETS is subject to continuing work within SMG and may change following formal SMG
approval. Should SMG modify the contents of this ETS, it will be resubmitted for OAP by ETSI with an
identifying change of release date and an increase in version number as follows:
Version 4.x.y
where:
4 indicates GSM Phase 2;
x the second digit is incremented for all changes of substance, i.e. technical enhancements,
corrections, updates, etc.
y the third digit is incremented when editorial only changes have been incorporated in the
specification.
Transposition dates
Date of adoption of this ETS: 22 January 1999
Date of latest announcement of this ETS (doa): 30 April 1999
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 31 October 1999
Date of withdrawal of any conflicting National Standard (dow): 31 October 1999
Introduction
This ETS contains the test specifications relating to the speech and transcoding aspects of a Base Station
System (BSS). It provides a means to ensure that the BSS operates in accordance with the core
specifications defined for GSM phase 2.
This ETS is a guide for manufacturers and users of GSM equipment and provides a common basis for the
characterization of the relevant system operational aspects.

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
1 Scope
This European Telecommunication Standard (ETS) specifies the testing requirements and methods for
GSM 900 and DCS 1800 Base Station Systems.
Unless otherwise specified, references to GSM also includes DCS1800.
This test specification covers the following functions in the BSS:
- definition of test points;
- speech coding/decoding;
- data rate adaption;
- speech and data transcoding with DTX;
- control of remote TRAU.
The tests in this document are based on the full set of GSM phase 2 ETSs. In cased of any inconsistency
between this specification and the source specifications, the source specifications shall prevail.
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] ETR 100 (GSM 01.04): "Digital cellular telecommunication system (Phase 2);
Abbreviations and acronyms".
[2] ETS 300 557 (GSM 04.08): "Digital cellular telecommunication system
(Phase 2); Mobile radio interface layer 3 specification".
[3] ETS 300 562 (GSM 04.21): "Digital cellular telecommunication system
(Phase 2); Rate adaption on the Mobile Station - Base Station System (MS -
BSS) interface".
[4] ETS 300 574 (GSM 05.02): "Digital cellular telecommunication system
(Phase 2); Multiplexing and multiple access on the radio path".
[5] ETS 300 575 (GSM 05.03): "Digital cellular telecommunication system
(Phase 2); Channel coding".
[6] ETS 300 578 (GSM 05.08): "Digital cellular telecommunication system
(Phase 2); Radio subsystem link control".
[7] ETS 300 580-1 (GSM 06.01): "Digital cellular telecommunication system
(Phase 2); Full rate speech processing functions".
[8] ETS 300 580-2 (GSM 06.10): "Digital cellular telecommunication system
(Phase 2); Full rate speech transcoding".
[9] ETS 300 580-3 (GSM 06.11): "Digital cellular telecommunication system
(Phase 2); Substitution and muting of lost frames for full rate speech channels".
[10] ETS 300 580-4 (GSM 06.12): "Digital cellular telecommunication system
(Phase 2); Comfort noise aspect for full rate speech traffic channels".
[11] ETS 300 580-5 (GSM 06.31): "Digital cellular telecommunication system
(Phase 2); Discontinuous Transmission (DTX) for full rate speech traffic
channel".
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
[12] ETS 300 580-6 (GSM 06.32): "Digital cellular telecommunication system
(Phase 2); Voice Activity Detection (VAD)".
[13] ETS 300 591 (GSM 08.20): "Digital cellular telecommunications system
(Phase 2); Rate adaption on the Base Station System -Mobile- services
Switching Centre (BSS - MSC) interface".
[14] ETS 300 593 (GSM 08.52): "Digital cellular telecommunication system
(Phase 2); Base Station Controller - Base Transceiver Station (BSC - BTS)
interface; Interface principles".
[15] ETS 300 594 (GSM 08.54): "Digital cellular telecommunication system
(Phase 2); Base Station Controller - Base Transceiver Station (BSC - BTS)
interface; Layer 1 structure of physical circuits".
[16] ETS 300 596 (GSM 08.58): "Digital cellular telecommunications system
(Phase 2); Base Station Controller - Base Transceiver Station (BSC -BTS)
interface Layer 3 specification".
[17] ETS 300 597 (GSM 08.60): "Digital cellular telecommunications system
(Phase 2); Inband control of remote transcoders and rate adaptors for full rate
traffic channels".
[18] ETS 300 607-1 (GSM 11.10-1): "Digital cellular telecommunications system
(Phase 2); Mobile Station (MS) conformance specification; Part 1: Conformance
specification".
[19] ETS 300 609-1 (GSM 11.21): "Digital cellular telecommunications system
(Phase 2); Base Station System (BSS) equipment specification; Part 1: Radio
aspects".
[20] ITU-T Recommendation I.460: "Multiplexing, rate adaption and support of
existing interfaces".
[21] ITU-T Recommendation V.110: "Support of data terminal equipments with
V-Series type interfaces by an integrated services digital network".
[22] ETS 300 581-1 (GSM 06.02): "Digital cellular telecommunication system
(Phase 2); Half Rate speech; Part 1: Half rate speech processing functions".
[23] ETS 300 581-7 (GSM 06.06): Digital cellular telecommunications system; Half
rate speech; Part 7: ANSI-C code for the GSM half rate speech codec“.
[24] ETS 300 581-8 (GSM 06.07): "Digital cellular telecommunication system
(Phase 2); Half rate speech; Part 8: Test sequences for the GSM half rate
speech codec".
[25] ETS 300 581-2 (GSM 06.20): "Digital cellular telecommunication system
(Phase 2); Half rate speech; Part 2: Half rate speech transcoding".
[26] ETS 300 581-3 (GSM 06.21): "Digital cellular telecommunication system
(Phase 2);Half rate speech; Part 3: Substitution and muting of lost frames for
half rate speech channels".
[27] ETS 300 581-4 (GSM 06.22): "Digital cellular telecommunication system
(Phase 2); Half rate speech; Part 4: Comfort noise aspects for the half rate
speech traffic channels".
[28] ETS 300 581-5 (GSM 06.41): "Digital cellular telecommunication system
(Phase 2);Half rate speech; Part 5: Discontinuous Transmission (DTX) for half
rate speech traffic channel".
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
[29] ETS 300 581-6 (GSM 06.42): "Digital cellular telecommunication system
(Phase 2); Half rate speech; Part 6: Voice Activity Detection (VAD)".
[30] ETS 300 598 (GSM 08.61): "Digital cellular telecommunications system
(Phase 2); Inband control of remote transcoders and rate adaptors for half rate
traffic channels".
[31] ETS 300 725 (GSM 06.54 ): "Digital cellular telecommunications system (Phase
2); Test vectors for the GSM Enhanced Full Rate (EFR) speech codec".
[32] ETS 300 723 (GSM 06.51): "Digital cellular telecommunications system;
Enhanced Full Rate (EFR) speech coding functions; General description".
[33] ETS 300 724 (GSM 06.53): "Digital cellular telecommunications system; ANSI-C
code for the GSM Enhanced Full Rate (EFR) speech codec".
[34] ETS 300 726 (GSM 06.60): "Digital cellular telecommunications system;
Enhanced Full Rate (EFR) speech transcoding".
[35] ETS 300 727 (GSM 06.61): "Digital cellular telecommunications system;
Substitution and muting of lost frames for Enhanced Full Rate (EFR) speech
traffic channels".
[36] ETS 300 728 (GSM 06.62): "Digital cellular telecommunications system;
Comfort noise aspects for Enhanced Full Rate (EFR) speech traffic channels".
[37] ETS 300 729 (GSM 06.81): "Digital cellular telecommunications system;
Discontinuous Transmission (DTX) for Enhanced Full Rate (EFR) speech traffic
channels".
[38] ETS 300 730 (GSM 06.82): "Digital cellular telecommunications system; Voice
Activity Detection (VAD) for Enhanced Full Rate (EFR) speech traffic channels".
[39] ETS 300 609-2 (GSM 11.23): "Digital cellular telecommunications system
(Phase 2); Base Station System (BSS) equipment specification; Part 1:
Signalling aspects".
3 Definitions and abbreviations
3.1 Definitions
Error-free radio conditions A condition for a test signal applied to the antenna connector, defined in
subclause 4.1.1.1
Perfect radio conditions A condition for a test signal applied to the antenna connector, defined in
subclause 4.1.1.1
3.2 Abbreviations
For the purposes of this ETS, the following abbreviations apply in addition to those given in ETR 100
(GSM 01.04) [1]:
AGCH Access Grant CHannel
BCCH Broadcast Control CHannel
BSS Base Station System
BTS Base Transceiver Station
CCU Channel Coder Unit
DTX Discontinuous Transmission
FACCH Fast Associated Control CHannel
FS Full rate Speech
HS Half rate Speech
MSC Mobile Switching Centre
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
OMC Operations and Maintenance Centre
PCH Paging CHannel
PCM Pulse Code Modulation
RA Rate Adaption
RACH Random Access CHannel
TCH Traffic CHannel
SACCH Slow Associated Control CHannel
SDCCH Standalone Dedicated Control CHannel
SCH Synchronization Channel
4 Transcoding and rate adaption
The Transcoding and Rate Adaption Unit (TRAU) is a GSM entity which converts between the 64 kbit/s
per channel bit rate at the MSC and a net rate of 13 kbit/s for the radio interface in the case of Full Rate
(FR) speech. For terrestrial links the 13 kbit/s data is transmitted over 16 kbit/s after the addition of
synchronisation and control information. On the radio interface the 13 kbit/s is padded to 22.8 kbit/s after
channel coding. In the case of data the net bit rates used as the bearer can be either 12 kbit/s, 6 kbit/s or
3,6 kbit/s. Again channel coding results in a radio interface data rate of 22.8 kbit/s. While the transcoder is
considered functionally part of the BSS it can be located at either the MSC location, BSC location or BTS
location. This aspect is illustrated in figure 11.24-1. The 16 kbit/s terrestrial link to the remote transcoder
may be (4 to 1) multiplexed onto a single 64 bit/s link as shown in BSS types 2,4 and 6.
In situations where the TRAU is located remote from the radio interface (i.e. BSS type 2, 4-7) speech or
data is transferred between the TRAU and channel codec unit (CCU) in frames of fixed length of 320 bits
(20ms). These "TRAU frames" also carry control signals that signal frame type and timing information. For
example in-call modifications from speech to data will be signalled from the CCU to the TRAU within the
frame structure. In the case of timing control the CCU checks the synchronisation of the downlink radio
link and signals advance/retard information to the TRAU over the uplink TRAU frames. Corrections are
then made to the downlink phasing of the TRAUs. For more information see GSM 08.60 [17].
Testing for the transcoding function will be divided into three categories:
- speech transcoding/DTX which is independent of BSS type;
- data rate adaption;
and
- In-band control which relates to types 2,4-7.
4.1 Transcoder test points
To facilitate the standardization of the testing the following interfaces are required:
4.1.1 External interfaces
The mandatory external interfaces of the BSS (according to figure 11.24-1) are listed below:
1. The antenna connector.
2. The A-interface to the MSC.
An additional optional external interface may be required:
3. The separate OMC-interface.
4.1.1.1 Test signals applied to the antenna connector
The purpose of the tests in this specification are to test the transcoding function of the BSS. Where tests
are performed using the antenna connector as an external interface, the characteristics of the RF test
signal should be chosen so as to minimise the contribution of the BTS (especially its RF parts) the
measurement results.
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
NOTE: The BTS can contribute to the measurement result is due to the introduction of bit
errors. This is most likely to occur if the level of the input signal is not large enough
compared to the noise floor of the receiver, but can also occur if the input signal
overloads the receiver.
The manufacturer may specify the RF characteristics of the test signal for these tests, which meet these
requirements.
If the manufacturer does not specify the characteristics of the test signal, the signal and general test
method defined in GSM 11.21 [19] for static reference sensitivity may be used, except that the level of the
signal should be increased by at least 20dB.
Perfect radio conditions: Using a test signal as defined above, applied continuously to the antenna
connector.
Error-free radio conditions: Using a test signal as defined above, applied for certain parts of the GSM
radio interface frame structure, as defined in each test.
Alternatively, an internal interface point within the BTS may be used, with a test signal comprising the bit
sequence which would result at the internal interface point for an error free test signal applied to the
antenna connector.
4.1.2 Internal test points and interfaces
In addition to the external interfaces in clause 4.1.1 the following internal logical interfaces shall as a
minimum be accessible in the equipment in order to carry out the measurements in this specification:
1. Input and output bit access to 104 kbit/s level, 13 bit linear PCM for full rate speech channels
(TCH/FS) in both directions of transmission and reset control of the speech encoder and decoder.
2. Output bit access after channel decoding including frame erasure information (FEI or BFI) for all
channel types.
3. Input bit access before channel encoding for all channel types.
4. The optional internal TRAU interface (referred to as Abis in GSM 08.60 [17]), if used.
Where an internal access is required, the implementation of this is up to the manufacturer. However, in
order to physically interface with the BSSTE, the implementation is restricted to the following options:
a. Direct physical access to the logical interface.
b. Physical access via a dedicated external interface adapter.
c. Physical access to bits (insertion and monitoring) before channel encoding/after channel decoding
via a loop-back over the radio path as defined in GSM 11.10-1 [18] for the Mobile Station.
d. Physical access to bits (insertion and monitoring) before channel encoding/after channel decoding
from the A-interface using the A-interface rate adaptation functions.
e. Physical access to bits (insertion and monitoring) before channel encoding/after channel decoding
from the Abis-interface using the 16 kbit/s Abis-interface rate adaptation and speech handling
functions, if any.
f. Physical access to 13 bit/8 kHz PCM samples via a special combination of 2 x A- or Abis-interface
64 kbit/s channels.
A dedicated external adapter shall, if used, be supplied by the BSS manufacturer.
The internal test points or interfaces are illustrated in figure 11.24-2 and figure 11.24-3 for the various
Base Station System types described in figure 11.24-1.
The detailed specifications of the interface points are:

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
- Interface point x:
TCH/FS: Input and output 104 kbit/s = 13 bit linear PCM at 8 kHz sampling rate
Reset control of the full rate speech encoder
TCH/HS: Input and output 104 kbit/s = 13 bit linear PCM at 8 kHz sampling rate
Reset control of the half rate speech encoder
No other channels are applicable.
- Interface point x':
TCH/FS: Input and output 104 kbit/s = 13 bit linear PCM at 8 kHz sampling rate
Reset control of the full rate speech decoder (or at interface point y')
TCH/HS: Input and output 104 kbit/s = 13 bit linear PCM at 8 kHz sampling rate
Reset control of the half rate speech decoder
No other channels are applicable.
- Interface point y:
Speech:
TCH/FS: Input/output 13 kbit/s = 260 bits every 20 ms
TCH/HS: Input/output 5.6 kbit/s = 112 bits every 20 ms
NOTE 1: For BSS types 4-7 input/output control can be handled via the Abis-interface.
Data:
TCH/F9,6: Input 12 kbit/s = 60 bits every 5 ms
TCH/F4,8: Input 6 kbit/s = 60 bits every 10 ms
TCH/F2,4: Input 3,6 kbit/s = 72 bits every 10 ms
TCH/H4,8: Input 6 kbit/s = 60 bits every 20 ms
TCH/H2,4: Input 3,6 kbit/s = 72 bits every 20 ms
Signalling:
FACCH/F: Input 184 bits (23 octets) every 20 ms
FACCH/H: Input 184 bits (23 octets) every 40 ms
SACCH/TF: Input 184 bits (23 octets) every 480 ms
SACCH/TH: Input 184 bits (23 octets) every 480 ms
SACCH/C8: Input 184 bits (23 octets) every 470.77 ms
SACCH/C4: Input 184 bits (23 octets) every 470.77 ms
SDCCH/8: Input 184 bits (23 octets) every 235.38 ms
SDCCH/4: Input 184 bits (23 octets) every 235.38 ms
BCCH: Input 184 bits (23 octets) every 235.38 ms
PCH: Input 184 bits (23 octets) every 235.38 ms
AGCH: Input 184 bits (23 octets) every 235.38 ms
RACH: Not applicable
SCH: Input 5 x 25 = 125 bits every 235.38 ms
- Interface point y':
Speech:
TCH/FS: Input/Output 13 kbit/s = 260 bits every 20 ms
Reset control of the full-rate speech decoder (or at interface point x')
TCH/HS: Input/Output 5.6 kbit/s = 112 bits every 20 ms
NOTE 2: For BSS types 4-7 input/output and reset control can be handled via the Abis-interface.
All outputs of speech channels shall include the Bad Frame Indication (BFI). All bits shall be
available, i.e. also bits in erased frames. No extrapolation shall be done.

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
Data:
TCH/F9,6: Output 12 kbit/s = 60 bits every 5 ms
TCH/F4,8: Output 6 kbit/s = 60 bits every 10 ms
TCH/F2,4: Output 3,6 kbit/s = 72 bits every 10 ms
TCH/H4,8: Output 6 kbit/s = 60 bits every 20 ms
TCH/H2,4: Output 3,6 kbit/s = 72 bits every 20 ms
Signalling:
FACCH/F: Output 184 bits (23 octets) every 20 ms
FACCH/H: Output 184 bits (23 octets) every 40 ms
SACCH/TF: Output 184 bits (23 octets) every 480 ms
SACCH/TH: Output 184 bits (23 octets) every 480 ms
SACCH/C8: Output 184 bits (23 octets) every 470.77 ms
SACCH/C4: Output 184 bits (23 octets) every 470.77 ms
SDCCH/8: Output 184 bits (23 octets) every 235.38 ms
SDCCH/4: Output 184 bits (23 octets) every 235.38 ms
BCCH: Not applicable
PCH: Not applicable
AGCH: Not applicable
RACH: Output 8 bits every 4.62 ms
SCH: Not applicable
All outputs of control channels shall include the Frame Erasure Indication (FEI). All bits shall
be available, i.e. also bits in erased frames.
Position Z: The 64 kbit/s level at the MSC interface ie. the A interface.
Position T: The TRAU or Abis-interface (Usually at 16 kbit/s submultiplexed into a
64 kbit/s channel). This is the link between the TRAU and the CCU in the
BSS or BTS.
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
BSS type 1
BSS TRAU MSC
(BSS to TRAU
interface
internal)
BSS type 2
BSS TRAU MSC
(BSS to TRAU
interface
external)
BSS type 3
BTS TRAU BSC MSC
(BTS to TRAU
interface
in tern al)
BSS type 4
BTS BSC TRAU MSC
(BTS to TRAU
interface
external)
BSS type 5
BTS BSC TRAU MSC
(BTS to TRAU
interface
external)
BSS type 6
BTS BSC TRAU MSC
(BTS to TRAU
interface
external)
BSS type 7
BTS BSC TRAU MSC
(BTS to TRAU
interface
external)
Figure 11.24-1: BSS types
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
TRAU BSS or BTS
x
A I/F y
Speech
8/13 Ch.
Z
bits
encoder encoder
(1)
Interleaver
RA1/ Ch. encrypter
Z
RA2 mux
RA1' encoder
(2)
(multiple access)
Ch.
encoder
(3)
Other speech traffic channels
Other data traffic channels
Other control channels
Modem
x' y'
13/8 Speech Ch.
Z'
bits decoder
decoder
(1)
Deinterleaver
decrypter
RA1/ Ch.
dem ux
Z'
RA2
(m ultiple access)
RA1'
decoder
(2)
(1) Speech traffic channel
(2) Data traffic channel
Ch.
(3) Control channel
decoder
(3)
Other speech traffic channels
Other data traffic channels
Other control channels
Figure 11.24-2:Test points or interfaces (BSS type 1 & 3)

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
TRAU BTS/BSC
Rem ote Control Protocol
x
(ref 08.60)
y
A I/F
A or A-bis
Remote
Speech Ch.
8/13 Speech
Z
speech
T
encoder
bits encoder
handler handler
(1)
Ch.
RA1/
Z
Interleaver
RA2 RAA RAA
T encoder
RA1'
encrypter
(2)
mux
(multiple access)
Ch.
encoder
(3)
Other speech traffic channels
Other data traffic channels
Other control channels
x'
y'
Modem
Remote
Speech
8/13 Ch.
Speech
Z'
speech
T' handler decoder
bits decoder
handler
(1)
Deinterleaver
RA1/ Ch.
decrypter
Z'
RA2 RAA RAA
decoder dem ux
T'
RA1'
(2)
(m ultiple access)
N ote: TRAU function rem ote from
radio interface
Ch.
decoder
(3)
(1) Speech traffic channel Other speech traffic channels
Other data traffic channels
(2) Data traffic channel
(3) Control channel Other control channels
Figure 11.24-3: Test points or interfaces (BSS types 2, 4-7)

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
5 Test descriptions for speech related transcoding function
5.1 Test descriptions for full rate speech related transcoding functions
The Full Rate (FR) speech transcoding process consists of two fundamental steps. In the uplink, the first
step transforms the 13 kbit/s bitstream into 104 kbit/s (13 bit linear PCM at 8 kHz). The second step
transforms this 13 bit linear PCM into 8 bit A law PCM. In the downlink, the order is reversed. This is
exactly followed in BSS types 1 and 3. For other BSS types, there is an intermediate step in which the 13
kbits/s data is mapped into a 16 kbit/s bitstream containing TRAU frames. TRAU frames are used to
transport coded speech and data between the TRAU and CCU. In addition, specific speech functions are
needed to support Discontinuous Transmission (DTX).
The test sequences for full rate speech transcoding are defined in GSM 06.10 [8] clause 5 and
GSM 06.32 [12] clause 4 and can be obtained from ETSI Secretariat.
For further information see GSM 06.01 [7], GSM 06.10 [8], GSM 06.11 [9], GSM 06.12 [10], GSM 06.31
[11], GSM 06.32 [12] and GSM 08.60 [17].
5.1.1 Uplink tests
5.1.1.1 Uplink speech transcoding - 13 kbit/s to 104 kbit/s conversion
Test purpose
To verify the bit exact conversion of the net 13 kbit/s radio path bit stream to 104 kbit/s (13 bit linear PCM
at 8 kHz) by the transcoding function operating on speech.
This test is applicable to BSS types 1 and 3.
Test case
Method of test
At 13 kbit/s level in the BSS, after channel decoding, a test sequence shall be input synchronized to the
channel/speech decoders interface frame structure. Alternatively, the test sequence may be input via the
air interface before channel encoding at 13 kbit/s level in the BSSTE. In the latter case the Layer 1
functions of the BSS must already be verified and the test must be performed under perfect radio
conditions.
The sequences to be input in this test are contained in the files SEQ01.COD, SEQ03.COD, SEQ04.COD
and SEQ05.COD. The files contain 16 bit words for all speech encoded parameters and are justified as
described in GSM 06.10 [8] table 5.1. 76 words must be input in a period of 20 ms and the speech
decoder must be reset before the start of the test (i.e. exactly before the start of the test sequences).
At 104 kbit/s level in the BSS, the output bit stream shall be recorded.
The transcoder may be put into test mode in order to accept the new input interface conditions (speech
decoder reset), to generate output data at the test rate (104 kbit/s) and in order to disable the uplink DTX
functions, which are not part of this test.
NOTE: The test sequences are stored on the diskettes as 16 bit words (2 bytes) where the
least significant byte occurs first and the most significant byte occurs last (e.g. stored
10 0A hex is to be understood as 0A 10 hex).
Test Requirements
The output test point for all BSS types is test point x' shown in figure 11.24-2.
The output bit stream from the speech transcoder shall be continuous and bit by bit exactly the same as
the predefined output sequences (SEQ01.OUT, SEQ03.OUT, SEQ04.OUT, SEQ05.OUT).

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
Conformance requirement
The transcoding algorithm requires that the 13 kbit/s compressed speech be first converted into a
104 kbit/s linear PCM bit stream. For correct interworking between the MS and BSS the conversion
process is precisely defined.
Requirement reference
GSM 06.01 [7] clause 2
GSM 06.10 [8] clause 5.2.2
5.1.1.2 Uplink speech transcoding - 13 kbit/s to 16 kbit/s conversion
Test purpose
To verify the bit exact conversion of the net 13 kbit/s radio path bit stream to TRAU frames at 16kbit/s by
the transcoding function operating on speech.
This test is applicable to BSS types 2, 4-7.
Test case
Method of test
At 13 kbit/s level in the BSS after channel decoding a test sequence shall be input synchronized to the
channel/speech decoders interface frame structure. Alternatively, the test sequence may be input via the
air interface before channel encoding at 13 kbit/s level in the BSSTE. In the latter case the Layer 1
functions of the BSS must already be verified and the test must be performed under perfect radio
conditions.
The test sequences for speech transcoding are defined in GSM 06.10 [8] clause 5 and can be obtained
from ETSI Secretariat (see GSM 06.10 [8]).
The input shall be maintained for a duration of at least a duration of 40 ms or 2 speech frames.
At the Abis-interface (position T) the output bit stream shall be recorded.
The uplink DTX functions may be disabled as it is not part of this test.
Test requirements
The data in the TRAU frames shall be bit exact with the input data.
Conformance requirement
The 13 kbit/s raw data taken from the radio interface is mapped onto TRAU frames which are used to
send the data to the transcoder located at the remote end.
Requirement reference
GSM 08.60 [17] clause 3.1
5.1.1.3 Uplink speech transcoding - 16 kbit/s to 104 kbit/s conversion
Test purpose
To verify the bit exact conversion of the encoded data in the TRAU frames to 13 bit/8 kHz linear PCM by
the transcoding function operating on speech.
This test is applicable to BSS types 2, 4-7.

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
Test case
Method of test
Conditions are as in clause 5.1.1.1 except that the test sequence shall be inserted at the 16 kbps TRAU
interface with the traffic bits being the same as the bits used in the 13 kbps interface point as used for
BSS types 1 and 3 in clause 5.1.1.1.
Test requirements
As in clause 5.1.1.1.
Conformance requirements
The 13 kbit/s data is extracted from the TRAU frames by the transcoder and converted to 104 kbit/s linear
PCM.
Requirement reference
GSM 06.10 [8] Speech decoder parts
5.1.1.4 Uplink speech transcoding - 104 kbit/s to 64 kbit/s conversion
Test purpose
To verify that the transcoding function correctly transforms 13 bit linear PCM to 8 bit A-law PCM in a bit
exact manner.
This test is applicable to BSS types 1-7.
Test case
Method of test
A test sequence containing all possible 13 bit codewords shall be input at 104 kbit/s level in the BSS. Test
point x' shall be used for inserting the test signal. At 64 kbit/s level in the BSS (position Z) the output shall
be recorded.
The transcoder may be put into test mode in order to enable the input test interface (104 kbit/s).
Test Requirements
The correspondence between codewords at input and output shall be according to recommendation
CCITT G.721 clause 4.2.1 subblock COMPRESS. The parameter LAW=1 shall be used.
Conformance requirement
The transcoding algorithm requires that the 104 kbit/s linearly encoded speech be converted to a 64 kbit/s
A law PCM data stream. For correct interworking between the MS and BSS, the conversion process must
be totally compatible.
Requirement reference
GSM 06.10 [8]
5.1.1.5 Uplink Speech Decoder - 13 kbit/s to 104 kbit/s conversion with DTX
Test purpose
To verify the correct operation of the SID-frame detector, comfort noise generator, speech extrapolation
and muting functions when the TRAU is at the radio interface.

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
This test is applicable to BSS types 1 and 3.
Test case
Method of test
At 13 kbit/s level in the BSSTE (before channel encoding) coded "speech" traffic frames containing a
special test signal defined below shall be input and transmitted over error-free radio conditions. All traffic
frames shall be identical with the exception of some frames which are SID-frames as defined in
GSM 06.31 [11].
At 104 kbit/s level in the BSS (13 bit linear PCM at 8 kHz), the signal shall be output and the signal energy
of the PCM signal shall be evaluated (as a mean square average) and recorded for each block of 20 ms
synchronized to the 20 ms speech frame structure.
The TDMA frames of the TCH/FS transmitted on the radio path shall be ramped "on" or "off" on a traffic
frame by traffic frame basis, taking into account the block-diagonal interleaving scheme defined in
GSM 05.03 [5]. The first traffic frame in step 1 shall occur one frame after the window of the SACCH
multiframe (TDMA frame 60 modulo 104) allocated for the SID-frame (see GSM 05.02 [4] and 05.08 [6]).
The SACCH shall be transmitted.
NOTE: 8 timeslots in 8 consecutive TCH/FS TDMA-frames shall be seen as one traffic frame
and the next traffic frame starts in the middle of the previous one (i.e. after 4
TDMA-frames of the previous one) due to the block diagonal interleaving scheme
defined in GSM 05.03 [5].
The special test frame is an encoded "speech" traffic frame of 260 bits obtained from white Gaussian
noise band limited to 300 - 3 400 Hz. When repeated, the special test frame results in a humming sound
with a fairly constant level when decoded, and is defined in table 11.24-1:

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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
Table 11.24-1: Special test traffic frame for receiver DTX tests
Encoded Value:
parameter:
LARc(1) 38
LARc(2) 42
LARc(3) 24
LARc(4) 20
LARc(5) 10
LARc(6) 9
LARc(7) 5
LARc(8) 3
Subblock no:
01 23
Grid position (Mc) 1 3 2 0
Block amplitude (xmaxc) 40 40 40 40
LTP gain (Bc) 0 0 0 0
LTP lag (Nc) 40 120 40 120
RPE pulses (xmc)
- pulse no 1 4 6 6 6
- pulse no 2 4 5 4 3
- pulse no 3 2 1 3 4
- pulse no 4 6 2 1 3
- pulse no 5 3 6 4 1
- pulse no 6 5 1 6 3
- pulse no 7 5 2 5 5
- pulse no 8 5 6 2 1
- pulse no 9 1 3 4 4
- pulse no 10 3 2 4 3
- pulse no 11 5 5 4 5
- pulse no 12 6 1 2 2
- pulse no 13 1 3 4 3
The signal energy of the special test frame is controlled with the block amplitude parameter (xmaxc).
Reducing xmaxc from 40 to 32 reduces the signal energy by 6 dB, and reducing xmaxc from 40 to 24
reduces the signal energy by 12 dB.
The sequence of frames shall be as follows:
1. 23 test frames "on".
2. 20 frames "off".
3. 20 test frames "on".
4. 1 SID-frame followed by 6 frames "off", another identical SID-frame and 23 frames "off". Except for
the SID codeword, the SID-frames shall be identical to the special test frame.
5. 1 different SID-frame, however with 2 to 15 errors inserted in the SID codeword, followed by
23 frames "off".
6. 20 test frames "on", but with the block amplitude parameter xmaxc=24.
7. 1 SID-frame followed by 50 frames "off". Except for the SID codeword, the SID-frames shall be
identical to the special test frame.
8. The whole test shall be repeated, but the frames "off" shall be replaced by frames "on" with the
FACCH flag set.
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ETS 300 609-3 (GSM 11.24 version 4.3.1): January 1999
Test Requirements
1) In the case of step 1, the signal energy shall be fairly constant within +/- 3 dB.
2) In the case of step 2, the signal energy shall decrease by greater than 40 dB within 17 frames.
3) In the case of step 3, the same requirements as in step 1 apply.
4) In the case of step 4, comfort noise shall be generated. The same requirements as in step 1 apply
(in terms of level).
5) In the case of step 5, the same requirements as in step 4 apply.
6) In the case of step 6, the same requirements as in step 1 apply. However, the signal energy shall
be 12 dB lower.
7) In the case of step 7, the signal energy shall be fairly constant within +/- 3 dB for 28 frames. Then
the signal energy shall decrease by greater than 40 dB within 16 frames.
8) In the case of step 8, the same requirements as in all previous steps apply.
Conformance requirement
1) The output level of the decoder  be constant for an input signal consisting of identical speech
...