SIST ETS 300 976 E1:2003

Digital cellular telecommunications system (Phase 2+) (GSM); General requirements on interworking between the Public Land Mobile Network (PLMN) and the Integrated Services Digital Network (ISDN) or Public Switched Telephone Network (PSTN) (GSM 09.07 version 5.2.2)

This European Telecommunication Standard (ETS) identifies the Mobile-s ervices Switching Centre/Interworking Functions (MSC/IWFs) and require ments to support interworking between: a)   PLMN and PSTN b)   PLMN and ISDN  It is not possible to treat ISDN and PSTN as one type of network, even when both ISDN and PSTN subscribers are served by the same exchange b ecause of the limitations of the PSTN subscribers access i.e. analogue connection without D-channel signalling. Within this ETS, the requirements for voice and non-voice (data) calls are considered separately.

Digitalni celični telekomunikacijski sistem (faza 2+) – Splošne zahteve za medsebojno delovanje javnega kopenskega mobilnega omrežja (PLMN) in digitalnega omrežja z integriranimi storitvami (ISDN) ali javnega komutiranega telefonskega omrežja (PSTN) (GSM 09.07, različica 5.2.2)

General Information

• Status: Published
• Publication Date: 30-Nov-2003
• ICS: 33.040.35 - Telephone networks
• ICS: 33.070.50 - Global System for Mobile Communication (GSM)
• ICS: 33.080 - Integrated Services Digital Network (ISDN)
• 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
• Ref Project: ETSI ETS 300 976 ed.1 (1997-05) - Digital cellular telecommunications system (Phase 2+) (GSM); General requirements on interworking between the Public Land Mobile Network (PLMN) and the Integrated Services Digital Network (ISDN) or Public Switched Telephone Network (PSTN) (GSM 09.07 version 5.2.2)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ETS 300 976 E1:2003
01-december-2003
'LJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHPID]D±6SORãQH]DKWHYH]D
PHGVHERMQRGHORYDQMHMDYQHJDNRSHQVNHJDPRELOQHJDRPUHåMD3/01LQ
GLJLWDOQHJDRPUHåMD]LQWHJULUDQLPLVWRULWYDPL,6'1DOLMDYQHJDNRPXWLUDQHJD
WHOHIRQVNHJDRPUHåMD3671*60UD]OLþLFD
Digital cellular telecommunications system (Phase 2+) (GSM); General requirements on
interworking between the Public Land Mobile Network (PLMN) and the Integrated
Services Digital Network (ISDN) or Public Switched Telephone Network (PSTN) (GSM
09.07 version 5.2.2)
Ta slovenski standard je istoveten z: ETS 300 976 Edition 1
ICS:
33.040.35 Telefonska omrežja Telephone networks
33.070.50 Globalni sistem za mobilno Global System for Mobile
telekomunikacijo (GSM) Communication (GSM)
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST ETS 300 976 E1:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ETS 300 976 E1:2003

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SIST ETS 300 976 E1:2003
EUROPEAN ETS 300 976
TELECOMMUNICATION May 1997
STANDARD
Source: ETSI TC-SMG Reference: DE/SMG-040907QR2
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+);
General requirements on interworking between the Public Land
Mobile Network (PLMN) and the Integrated Services Digital
Network (ISDN) or Public Switched Telephone Network (PSTN)
(GSM 09.07 version 5.2.2)
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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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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Contents
Foreword .7
1 Scope .9
2 Normative references.9
3 Definitions and abbreviations .11
4 Introduction.12
5 Not used.13
6 Network Characteristics .13
6.1 Key Characteristics of Networks Concerned .13
6.1.1 Characteristics of PLMNs.14
6.1.2 Characteristics of PSTNs .14
6.1.3 Characteristics of ISDN.14
7 Interworking classifications .14
7.1 Service interworking.14
7.2 Network interworking .14
7.3 Signalling interworking .16
7.4 Numbering .16
7.5 Supplementary service interworking.16
8 Compatibility and subscription checking .17
9 Interworking to PSTN .17
9.1 Speech Calls.17
9.1.1 Interworking indications to PLMN terminal.17
9.1.2 Transmission aspects .17
9.1.3 Generation of In-band Tones and Announcements (PLMN-PSTN).17
9.2 Data Calls .17
9.2.1 Network interworking mobile originated .18
9.2.1.1 Selection of interworking function.18
9.2.1.2 Modem Selection.18
9.2.1.3 DTE/Modem interface (Filtering) .19
9.2.1.4 Mapping of BC-IE from GSM 04.08 to ISUP (or other).20
9.2.2 Network Interworking Mobile terminated PSTN Originated.20
9.2.3 Transparent service support .24
9.2.3.1 Not used .24
9.2.3.2 Rate adaptation process in MSC/IWF .24
9.2.3.3 Mapping of signalling MS/MSC/IWF to modem interface
requirements.24
9.2.3.4 Establishment of end-to-end terminal synchronizations .25
9.2.3.5 Network Independent Clocking (NIC).26
9.2.4 Non-transparent service support.26
9.2.4.1 MSC-IWF Rate adaptation scheme.26
9.2.4.2 Protocol layer structure in the MSC/IWF .26
9.2.4.3 Re-constitution of user data.26
9.2.4.4 Layer 2 relay functionality .27
9.2.4.5 In band signalling mapping flow control.27
9.2.4.5.1 Conditions requiring flow control
towards the fixed network .27
9.2.4.5.2 Conditions requiring flow control
towards the MS.28

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9.2.4.6 Data buffers . 28
9.2.4.6.1 Transmit buffers (towards MS). 28
9.2.4.6.2 Receive buffers (from MS) . 28
9.2.4.7 Transportation of the Break condition. 28
9.2.4.8 In band signalling mapping modem status information. 28
9.2.4.9 Support of out-band flow control . 28
9.2.4.10 Establishment of end-to-end terminal synchronizations . 29
9.2.4.11 Data compression. 29
9.3 Interworking Alternate Speech / Data Calls. 30
9.3.1 Alternate Speech/Data Interworking. 30
9.3.1.1 General . 30
9.3.1.2 Mobile originated PSTN terminated calls. 30
9.3.1.3 PSTN originated mobile terminated calls. 30
9.3.2 Speech followed by data interworking . 31
9.3.2.1 General . 31
10 Interworking to the ISDN. 31
10.1 Speech Calls . 31
10.2 Data Calls. 31
10.2.1 Network interworking mobile originated. 32
10.2.1.1 Circuit switched calls. 32
10.2.1.2 Packet calls. 32
10.2.2 Network interworking mobile terminated . 32
10.2.2.1 Circuit switched calls. 47
10.2.2.2 Packet calls. 47
10.2.3 Transparent service support (see GSM 03.10) . 47
10.2.3.1 MSC - IWF rate adaptation scheme . 47
10.2.3.2 Rate adaptation process in MSC/IWF . 47
10.2.3.3 Mapping of signalling MS/MSC/IWF to modem interface
requirements . 47
10.2.3.4 Establishment of end-to-end terminal synchronizations . 48
10.2.3.5 Network independent Clocking (NIC). 48
10.2.4 Non-transparent service support (see GSM 03.10). 48
10.2.4.1 MSC - IWF Rate adaptation scheme. 49
10.2.4.2 Protocol layer structure in the MSC/IWF. 49
10.2.4.3 Re-constitution of user data . 49
10.2.4.4 Layer 2 relay functionality. 49
10.2.4.5 In band signalling mapping flow control . 49
10.2.4.5.1 Conditions requiring flow control - if
flow control is provided -towards the
fixed network . 50
10.2.4.5.2 Conditions requiring flow control
towards the MS . 50
10.2.4.6 Data buffers . 50
10.2.4.6.1 Transmit buffers (towards MS). 50
10.2.4.6.2 Receive buffers (from MS) . 51
10.2.4.7 BREAK Indication. 51
10.2.4.8 Signalling mapping modem status information or in band
rate adapted frame information. 51
10.2.4.9 Support of out-band flow control . 51
10.2.4.10 Synchronizations. 51
10.2.4.10.1 V110 Frame synchronizations. 51
10.2.4.10.2 RLP Frame start indication. 51
10.2.4.10.3 L2R Frame synchronizations. 51
10.2.4.10.4 Establishment of end-to-end terminal
synchronizations. 51
10.2.4.11 Data compression. 52
10.2.5 DTE/Modem interface (Filtering) . 52
10.3 Interworking Alternate speech data calls . 53
10.3.1 Alternate speech data bearer interworking. 53
10.3.1.1 General . 53
10.3.1.2 Mobile originated ISDN terminated . 54
10.3.1.3 ISDN originated mobile terminated . 54

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10.3.2 Speech followed by data interworking.54
10.3.2.1 General.54
11 V.110 Frame Synchronization .54
11.1 Initial V.110 frame synchronization .55
11.2 Action on loss of V.110 frame synchronization for non transparent services .55
11.3 Action on loss of V.110 frame synchronization for transparent services .55
Annex A (informative): SDLs.56
History.58

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Foreword
This European Telecommunication Standard (ETS) has been produced by the Special Mobile Group
(SMG) Technical Committee (TC) of the European Telecommunications Standards Institute (ETSI).
This ETS identifies the Mobile-services Switching Centre/Interworking functions (MSC/IWFs) and
requirements to support interworking between:
i) PLMN and PSTN;
ii) PLMN and ISDN;
within the digital cellular telecommunications system.
This ETS is a GSM technical specification version 5, which incorporates GSM Phase 2+
enhancements/features to the version 4 GSM technical specification. The ETS from which this Phase 2+
ETS has evolved, is Phase 2 GSM ETS 300 604 Edition 6 (GSM 09.07 version 4.12.0).
The contents of this ETS are subject to continuing work within TC-SMG and may change following formal
TC-SMG approval. Should TC-SMG modify the contents of this ETS it will then be resubmitted for OAP by
ETSI with an identifying change of release date and an increase in version number as follows:
Version 5.x.y
where:
y the third digit is incremented when editorial only changes have been incorporated in the
specification;
x the second digit is incremented for all other types of changes, i.e. technical enhancements,
corrections, updates, etc.
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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1 Scope
This European Telecommunication Standard (ETS) identifies the Mobile-services Switching
Centre/Interworking Functions (MSC/IWFs) and requirements to support interworking between:
a) PLMN and PSTN;
b) PLMN and ISDN.
It is not possible to treat ISDN and PSTN as one type of network, even when both ISDN and PSTN
subscribers are served by the same exchange because of the limitations of the PSTN subscribers access
i.e. analogue connection without D-channel signalling.
Within this ETS, the requirements for voice and non-voice (data) calls are considered separately.
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] CCITT Recommendation G.711: "Pulse code modulation (PCM) of voice
frequencies".
[2] CCITT Recommendation I.460: "Multiplexing, rate adaption and support of
existing interfaces".
[3] CCITT Recommendation V.25: "Automatic answering equipment and/or parallel
automatic calling equipment on the general switched telephone network
including procedures for disabling of echo control devices for both manually and
automatically established calls".
[4] CCITT Recommendation V.42bis: "Data Compression for Data Circuit
Terminating Equipment (DCE) using Error Correction Procedures".
[5] CCITT Recommendation V.110: "Support of data terminal equipments (DTEs)
with V-series interfaces by an integrated services digital network".
[6] ETS 300 102-1 Edition 1 (1990): "Integrated Services Digital Network (ISDN);
User-network interface layer 3 Specifications for basic call control".
[7] ETS 300 121: "Integrated Services Digital Network (ISDN); Application of the
ISDN User Part (ISUP) of CCITT Signalling System No.7 for international ISDN
interconnections (ISUP version 1)".
[8] GSM 01.04 (ETR 350): "Digital cellular telecommunications system (Phase 2+);
Abbreviations and acronyms".
[9] GSM 02.01: "Digital cellular telecommunications system (Phase 2+); Principles
of telecommunications services supported by a GSM Public Land Mobile
Network (PLMN)".
[10] GSM 02.02 (ETS 300 904): "Digital cellular telecommunications system
(Phase 2+); Bearer Services (BS) supported by a GSM Public Land Mobile
Network (PLMN)".
[11] GSM 02.03 (ETS 300 905): "Digital cellular telecommunications system
(Phase 2+); Teleservices supported by a GSM Public Land Mobile Network
(PLMN)".

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[12] GSM 02.04 (ETS 300 918): "Digital cellular telecommunications system
(Phase 2+); General on supplementary services".
[13] GSM 02.81: "Digital cellular telecommunications system; Line identification
Supplementary Services - Stage 1".
[14] GSM 02.82: "Digital cellular telecommunications system (Phase 2+); Call
Forwarding (CF) supplementary services - Stage 1".
[15] GSM 02.83: "Digital cellular telecommunications system; Call Waiting (CW) and
Call Hold (HOLD) Supplementary Services - Stage 1".
[16] GSM 02.84: "Digital cellular telecommunications system; MultiParty (MPTY)
Supplementary Services - Stage 1".
[17] GSM 02.85: "Digital cellular telecommunications system; Closed User Group
(CUG) Supplementary Services - Stage 1".
[18] GSM 02.86: "Digital cellular telecommunications system; Advice of charge
(AoC) Supplementary Services - Stage 1".
[19] GSM 02.88: "Digital cellular telecommunications system; Call Barring (CB)
Supplementary Services - Stage 1".
[20] GSM 03.03 (ETS 300 927): "Digital cellular telecommunications system
(Phase 2+); Numbering, addressing and identification".
[21] GSM 03.08: "Digital cellular telecommunications system (Phase 2+);
Organization of subscriber data".
[22] GSM 03.11 (ETS 300 928): "Digital cellular telecommunications system;
Technical realization of supplementary services".
[23] GSM 03.45 (ETS 300 931): "Digital cellular telecommunications system
(Phase 2+); Technical realization of facsimile group 3 transparent".
[24] GSM 03.46: "Digital cellular telecommunications system; Technical realization of
facsimile group 3 non-transparent".
[25] GSM 03.50 (ETS 300 903): "Digital cellular telecommunications system
(Phase 2+); Transmission planning aspects of the speech service in the GSM
Public Land Mobile Network (PLMN) system".
[26] GSM 04.08 (ETS 300 940): "Digital cellular telecommunications system
(Phase 2+); Mobile radio interface layer 3 specification".
[27] GSM 04.21 (ETS 300 945): "Digital cellular telecommunications system
(Phase 2+); Rate adaption on the Mobile Station - Base Station System (MS -
BSS) Interface".
[28] GSM 04.22 (ETS 300 946): "Digital cellular telecommunications system
(Phase 2+); Radio Link Protocol (RLP) for data and telematic services on the
Mobile Station - Base Station System (MS - BSS) interface and the Base Station
System - Mobile-services Switching Centre (BSS - MSC) interface".
[29] GSM 07.01 (ETS 300 913): "Digital cellular telecommunications system
(Phase 2+); General on Terminal Adaptation Functions (TAF) for Mobile
Stations (MS)".
[30] GSM 07.02 (ETS 300 914): "Digital cellular telecommunications system
(Phase 2+); Terminal Adaptation Functions (TAF) for services using
asynchronous bearer capabilities".

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[31] GSM 07.03 (ETS 300 915): "Digital cellular telecommunications system
(Phase 2+); Terminal Adaptation Functions (TAF) for services using
synchronous bearer capabilities".
[32] GSM 07.05: "Digital cellular telecommunications system (Phase 2+); Use of
Data Terminal Equipment - Data Circuit terminating Equipment (DTE - DCE)
interface for Short Message Service (SMS) and Cell Broadcast Service (CBS)".
[35] GSM 08.20: "Digital cellular telecommunications system (Phase 2+); Rate
adaption on the Base Station System - Mobile-services Switching Centre (BSS -
MSC) interface".
[36] GSM 08.60 (ETS 300 737): "Digital cellular telecommunications system
(Phase 2+); Inband control of remote transcoders and rate adaptors for
Enhanced Full Rate (EFR) and full rate traffic channels".
[37] GSM 09.02 (ETS 300 974): "Digital cellular telecommunications system
(Phase 2+); Mobile Application Part (MAP) specification".
[38] GSM 09.03: "Digital cellular telecommunications system; Signalling
requirements on interworking between the Integrated Services Digital Network
(ISDN) or Public Switched Telephone Network (PSTN) and the Public Land
Mobile Network (PLMN)".
[39] GSM 09.05: "Digital cellular telecommunications system; Interworking between
the Public Land Mobile Network (PLMN) and the Packet Switched Public Data
Network (PSPDN) for Packet Assembly/Disassembly facility (PAD) access".
[40] GSM 09.06 (ETS 300 975): "Digital cellular telecommunications system
(Phase 2+); Interworking between a Public Land Mobile Network (PLMN) and a
Packet Switched Public Data Network/Integrated Services Digital Network
(PSPDN/ISDN) for the support of packet switched data transmission services".
NOTE: As regards ETS 300 102-1 [6], the first edition of this ETS from 1990 shall be used,
with one exception: the encoding of the field modem type in the ISDN BC-IE shall be
handled as specified in table 6A and 6B of GSM 09.07.
3 Definitions and abbreviations
Use is made of the following terms within this ETS. These terms refer to information requirements
necessary to support interworking functions, some of these terms will be identifiable with their use in other
GSM specifications.
For the purposes of this ETS, the following definitions apply:
bearer capability information: Specific information defining the lower layer characteristics required
within the network.
low layer compatibility information: Information defining the lower layer characteristics of the terminal.
high layer compatibility information: Information defining the higher layer characteristics of the
terminal.
compatibility information: This term subsumes the entirety of Bearer Capability, Low Layer
Compatibility, High Layer Compatibility, Progress Indicator and Address Information conveyed out-of-band
prior to call establishment for the support of compatibility checking and terminal/function/service selection
at the ISDN-type user-network interface.
protocol identifier: Information defining the specific protocols utilized for the support of data transfer by a
terminal.

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progress indicator: Information supplied to indicate to the terminal that network interworking has taken
place.
out-of-band parameter exchange: Information exchanged via an associated or non-associated
signalling link e.g. SS No 7.
PSTN: Subscriber to network interface supports only analogue terminals.
ISDN: Subscriber to network interface supports digital or analogue terminals, plus a standardized user to
network associated signalling system and a standardized internetwork signalling system.
autobauding type 1: This information element value may be contained in the setup or call confirm
messages from the MS in association with a non transparent data service. This implies that the MSC/IWF
may select any speed and modem type according to what it can negotiate with the remote modem on the
PSTN/ISDN. The maximum speed to be used by the MSC/IWF is the user speed indicated in the
setup/call confirm message.
multi self selecting speed modem: This term applies to V series modems capable of handling one or
more lower speeds as a fall back position. When such a modem is requested in the call setup or call
confirm message from the MS in association with a non transparent service, the MSC/IWF may select any
of the speeds supported according to the negotiation with the remote modem on the PSTN/ISDN. In this
instance the maximum starting negotiation speed to be used by the MSC/IWF is the one indicated by the
user speed in the setup/call confirm message.
In addition to the following, abbreviations used in this ETS are listed in GSM 01.04 [8].
ADPCM Adaptive Differential Pulse Coded Modulation
DP Dial Pulse
ITC Information Transfer Capability
LE Local Exchange
NT Network Termination
PABX Private Automatic Branch Exchange
SPC Stored Program Control
SS No.7 Signalling System No.7
TE Terminal Equipment
TA Terminal Adaptor
TUP Telephone User Part (of Signalling System No.7)
DSS1 Digital Subscriber Signalling 1
UNI User Network Interface
4 Introduction
General Network Interworking Scenarios are described in GSM 09.01. Since the numbering plan for the
ISDN era (E.164) includes the numbering plan for the telephone network (E.163), it is not possible to
distinguish by the number whether a given subscriber is a PSTN or ISDN subscriber. Further, in some
countries both PSTN and ISDN subscribers will be connected to the same exchange, so the only
difference for this type of combined network will be in the nature of the customer access. In this document
a PSTN is considered to support only an analogue interface towards the subscriber. An ISDN shall be
considered to support digital interface towards the subscriber. In addition, the ISDN is considered to
support a standardized outband signalling protocol both between the subscriber and the network and
within the network, i.e. DSS1 and ISUP, thus enabling the generation and transport of Compatibility
Information for compatibility checking and terminal/function/service selection at the user-network interface
as well as for MSC/IWF selection.
There now exist networks which do not fall into either of these categories in that they provide for digital
connectivity from subscriber to subscriber through the network. The subscribers have access to a wide
range of services by a limited set of standard multi-purpose user network interfaces. However, these
networks do not support the standardized inter-exchange signalling protocol throughout, in that they are
e.g. using TUP or National User Part (NUP). These types of network support 64 kbit/s connections, so in
service support are comparable to ISDN, however, the signalling system provided may not support
transport of all Compatibility Information allowed for in the standardized ISDN signalling. This document
will therefore identify interworking to PSTN and ISDN on the principle of the network characteristics as

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identified in the previous clause. The afore-mentioned existing networks then constitute one particular
case in the ISDN interworking scenarios. These cases will be itemized when the implication of the various
degrees of exhaustiveness of the Compatibility Information - delivered via the ISDN - used for deducting a
GSM Basic Service needs to be set forth.
When two dissimilar networks are required to interwork in order to support a communication between two
subscribers, one on each network, a number of Interworking Functions (MSC/IWFs) are required
...