ETSI ETS 300 582 ed.2 (1995-07)
European digital cellular telecommunications system (Phase 2); General on Terminal Adaptation Functions (TAF) for Mobile Stations (MS) (GSM 07.01)
European digital cellular telecommunications system (Phase 2); General on Terminal Adaptation Functions (TAF) for Mobile Stations (MS) (GSM 07.01)
RE/SMG-040701P
Evropski digitalni celični telekomunikacijski sistem (faza 2) – Splošno o terminalskih prilagodilnih funkcijah (TAF) za mobilne postaje (MS) (GSM 07.01)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2003
(YURSVNLGLJLWDOQLFHOLþQLWHOHNRPXQLNDFLMVNLVLVWHP ID]D ±6SORãQRR
WHUPLQDOVNLKSULODJRGLOQLKIXQNFLMDK 7$) ]DPRELOQHSRVWDMH 06 *60
European digital cellular telecommunications system (Phase 2); General on Terminal
Adaptation Functions (TAF) for Mobile Stations (MS) (GSM 07.01)
Ta slovenski standard je istoveten z: ETS 300 582 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 300 582
TELECOMMUNICATION July 1995
STANDARD Second Edition
Source: ETSI TC-SMG Reference: RE/SMG-040701P
ICS: 33.060.30
European digital cellular telecommunications system, Global System for Mobile communications
Key words:
(GSM)
European digital cellular telecommunications system (Phase 2);
General on Terminal Adaptation Functions (TAF)
for Mobile Stations (MS)
(GSM 07.01)
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - secretariat@etsi.fr
X.400: Internet:
Tel.: +33 92 94 42 00 - Fax: +33 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 1995. All rights reserved.
New presentation - see History box
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
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 300 582: July 1995 (GSM 07.01 version 4.8.0)
Contents
Foreword.7
1.1 SCOPE .9
1.2 Normative references .9
1.3 Definitions and abbreviations.11
2 ACCESS REFERENCE CONFIGURATION .12
3 not used . 12
4 not used . 12
5 FUNCTIONS TO SUPPORT DATA SERVICES.13
6 SUPPORT OF NON TRANSPARENT BEARER SERVICES.13
6.1 Functions of the Layer 2 Relay.13
6.2 Radio Link Services Used .15
6.3 Flow Control - General Description.15
6.3.1 End to End Flow Control.15
6.3.2 Back Pressure .15
6.3.3 Receive not Ready.15
7 STRUCTURE OF THE GSM 07-SERIES OF SPECIFICATIONS.16
8 FUNCTIONS COMMON TO ALL INTERFACES.16
8.1 Synchronization of the Traffic Channel.16
8.2 Filtering of Channel Control Information.17
8.2.1 General . 17
8.2.2 Filtering Process to Be Applied.18
8.3 Terminal Compatibility Decision .19
8.3.1 Compatibility Check.19
8.3.2 Selection of Appropriate Terminal Function.20
8.3.3 Indication of Compatibility Requirements to the PLMN.20
8.3.3.1 Indication in case of Mobile Terminating Calls .20
8.3.3.2 Indication in case of Mobile originating calls.21
8.4 Test Loops .21
8.5 Alternate speech/data and speech/facsimile group 3.22
ANNEX 1 (Informative) List of Bearer Capability Elements.23
ANNEX 2 (Normative) : Setting of Bearer Capability, Low Layer Compatibility and High Layer
Compatibility Information Element for GSM Bearer Services and GSM
TeleServices.27
0 Scope .27
1 Bearer Capability Information Element .27
1.1 Introduction.27
1.1.1 General Consideration.27
1.1.2 Interpretation of the Diagrams. 28
Table II.1 BC-Parameters subject to negotiation procedure.29
Table II.2 General Structure of the BC-Information Element .30
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Table II.3 Selection of flow control method (for CENT with SAA
only) .30
Table II.4a Modem Type subject to negotiation procedure .31
Table II.4b Intermediate Rate negotiation procedure.32
Table II.5 BC parameter setting (part 1) .33
Table II.5 BC parameter setting (part 2) .34
Table II.6 Channel combinations.35
Table II.7 TS61/TS62 Negotiation rules .36
1.2 Bearer Service 21 . 26, Data Circuit Duplex Asynchronous .37
1.2.1 Unrestricted digital information transfer capability.37
1.2.2 3.1 kHz audio ex-PLMN information transfer capability.38
1.3. Bearer Service 31 . 34, Data Circuit Duplex Synchronous.39
1.3.1 Unrestricted digital information transfer capability.39
1.3.1.1 Non-X.32 Cases .39
1.3.1.2 X.32 Case (Packet Service) .40
1.3.2 3.1 kHz audio ex-PLMN information transfer capability.41
1.3.2.1 Non-X.32 Cases .41
1.3.2.2 X.32 Case ( Packet Service ) .42
1.4 Bearer Service 41 . 46, PAD Access Asynchronous.43
1.5 Bearer Service 51 . 53 ,Data Packet Duplex Synchronous, Unrestricted digital
information transfer capability.44
1.6 Bearer Service 61, Alternate Speech/Data.45
1.6.1 Bearer Service 61,Speech .45
1.6.2 Bearer Service 61, 3.1 kHz audio ex-PLMN information transfer capability.46
1.6.2.1 Asynchronous.46
1.6.2.2 Synchronous.47
1.7 Bearer Service 81, Speech followed by Data.48
1.7.1 Bearer Service 81,Speech .48
1.7.2 Bearer Service 81, 3.1 kHz audio ex-PLMN information transfer capability .48
1.7.2.1 Asynchronous.48
1.7.2.2 Synchronous.48
1.8 Teleservice 11 . 12, Speech.48
1.9 Teleservice 21 . 23, Short Message .48
1.10 Teleservice 61, Alternate Speech and Facsimile group 3.49
1.10.1 Teleservice 61, Speech.49
1.10.2 Teleservice 61, Facsimile group 3.49
1.11 Teleservice 62, Automatic Facsimile Group 3 .49
2 Low Layer/High Layer Compatibility Information Element.50
2.1 Introduction.50
2.1.1 General Consideration .50
2.1.2 Interpretation of the Tables .50
2.2 LLC Bearer Service 21 . 26.51
2.2.1 Unrestricted digital information transfer capability.51
2.2.2 3,1 kHz audio ex-PLMN information transfer capability.51
2.3 LLC Bearer Service 31 . 34.52
2.3.1 Unrestricted digital information transfer capability.52
2.3.2 3.1kHz audio ex-PLMN information transfer capability.52
2.4 LLC Bearer Services 41 . 46.52
2.5 LLC Bearer Services 51 . 53.53
2.5.1 Unrestricted digital information transfer capability.53
2.6 LLC Bearer Service 61 .53
2.6.1 3,1 kHz audio ex-PLMN information transfer capability,
Asynchronous.53
2.6.2 3,1 kHz audio ex-PLMN information transfer capability,
Synchronous.53
2.7 LLC Bearer Service 81 .53
2.7.1 3,1 kHz audio ex-PLMN information transfer capability,
Asynchronous.53
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2.7.2 3,1 kHz audio ex-PLMN information transfer capability,
Synchronous .53
2.8 HLC Teleservices 11 . 12.53
2.9 HLC Teleservices 21 . 23.53
2.10 HLC Teleservice 61.54
2.11 HLC Teleservice 62.54
History.55
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
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 describes the functions required for the terminal adaptation of terminal equipment to the Mobile
Termination (MT) within the European digital cellular telecommunications system (Phase 2).
This ETS is based upon the principles of terminal adaptor functions presented in the CCITT I-series of
recommendations (I.460 - I.463).
This ETS corresponds to GSM technical specification, GSM 07.01 version 4.8.0.
The specification from which this ETS has been derived was originally based on CEPT documentation,
hence the presentation of this ETS may not be entirely in accordance with the ETSI/PNE rules.
Reference is made within this ETS to GSM Technical Specifications (GSM-TS) (NOTE).
Reference is also made within this ETS to GSM 0x.xx. series. The specifications in the series can be
identified, with their full title, within the normative reference Clause of this ETS by the first two digits of
their GSM reference number e.g. GSM 09.xx series, refers to GSM 09.01, GSM 09.02, etc.
NOTE: TC-SMG has produced documents which give the technical specifications for the
implementation of the European digital cellular telecommunications system. Historically,
these documents have been identified as GSM Technical Specifications (GSM-TSs).
These TSs may have subsequently become I-ETSs (Phase 1), or ETSs (Phase 2),
whilst others may become ETSI Technical Reports (ETRs). GSM-TSs are, for editorial
reasons, still referred to in current GSM ETSs.
Proposed transposition dates
Date of adoption of this ETS: 30 July 1995
Date of latest announcement of this ETS (doa): 31 October 1995
Date of latest publication of new National Standard
or endorsement of this ETS (dop/e): 30 April 1996
Date of withdrawal of any conflicting National Standard (dow): 30 April 1996
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
1.1 SCOPE
This specification is based on the principles of terminal adaptor functions presented in the CCITT I-series
of recommendations (I.460 - I.463).
The GSM PLMN supports a wide range of voice and non-voice services in the same network. In order to
enable non-voice traffic in the GSM PLMN there is a need to connect various kinds of terminal equipments
to the Mobile Termination (MT). The target of this Specification is to outline the functions needed for the
terminal adaptation.
In the GSM 02.02 the bearer services are described. The general network configuration is described in
GSM 03.02 and the GSM PLMN access reference configuration is defined in GSM 04.02. The various
connection types used in the GSM PLMN are presented in GSM 03.10. Terminology used in this
Specification is presented in GSM 01.04. For support of data services between GSM PLMN and other
networks see GSM 09-series of Specifications.
1.2 Normative references
This ETS incorporates by dated and undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply
to this ETS only when incorporated in it by amendment or revision. For undated references, the latest
edition of the publication referred to applies.
[1] GSM 01.04 (ETR 100): "European digital cellular telecommunication system
(Phase 2); Definitions, abbreviations and acronyms".
[2] GSM 02.02 (ETS 300 501): "European digital cellular telecommunication system
(Phase 2); Bearer Services (BS) supported by a GSM Public Land Mobile
Network (PLMN)".
[3] GSM 02.03 (ETS 300 502): "European digital cellular telecommunication system
(Phase 2); Teleservices supported by a GSM Public Land Mobile Network
(PLMN)".
[4] GSM 03.02 (ETS 300 522): "European digital cellular telecommunication system
(Phase 2); Network architecture".
[5] GSM 03.10 (ETS 300 528): "European digital cellular telecommunication system
(Phase 2); GSM Public Land Mobile Network (PLMN) connection types".
[6] GSM 04.02 (ETS 300 551): "European digital cellular telecommunication system
(Phase 2); GSM Public Land Mobile Network (PLMN) access reference
configuration".
[7] GSM 04.08 (ETS 300 557): "European digital cellular telecommunication system
(Phase 2); Mobile radio interface layer 3 specification".
[8] GSM 04.21 (ETS 300 562): "European digital cellular telecommunication system
(Phase 2); Rate adaption on the Mobile Station - Base Station System (MS -
BSS) interface".
[9] GSM 04.22 (ETS 300 563): "European digital cellular telecommunication 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".
[10] GSM 05.05 (ETS 300 577): "European digital cellular telecommunication system
(Phase 2); Radio transmission and reception".
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
[11] GSM 07.02 (ETS 300 583): "European digital cellular telecommunication system
(Phase 2); Terminal Adaptation Functions (TAF) for services using asynchronous
bearer capabilities".
[12] GSM 07.03 (ETS 300 584): "European digital cellular telecommunication system
(Phase 2); Terminal Adaptation Functions (TAF) for services using synchronous
bearer capabilities".
[13] GSM 07.05 (ETS 300 585): "European digital cellular telecommunication 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)".
[14] GSM 07.06 (ETS 300 586): "European digital cellular telecommunication system
(Phase 2); Use of the V series Data Terminal Equipment - Data Circuit
terminating Equipment (DTE - DCE) interface at the Mobile Station (MS) for
Mobile Termination (MT) configuration".
[15] GSM 09.01 (ETR 109): "European digital cellular telecommunication system
(Phase 2); General network interworking scenarios".
[16] GSM 09.02 (ETS 300 599): "European digital cellular telecommunication system
(Phase 2); Mobile Application Part (MAP) specification".
[17] GSM 09.03 (ETS 300 600): "European digital cellular telecommunication system
(Phase 2); Signalling requirements on interworking between the Integrated
Services Digital Network (ISDN) or Public Switched Telephone Network (PSTN)
and the Public Land Mobile Network (PLMN)".
[18] GSM 09.04 (ETS 300 601): "European digital cellular telecommunication system
(Phase 2); Interworking between the Public Land Mobile Network (PLMN) and
the Circuit Switched Public Data Network (CSPDN)".
[19] GSM 09.05 (ETS 300 602): "European digital cellular telecommunication system
(Phase 2); Interworking between the Public Land Mobile Network (PLMN) and
the Packet Switched Public Data Network (PSPDN) for Packet
Assembly/Disassembly (PAD) facility access".
[20] GSM 09.06 (ETS 300 603): "European digital cellular telecommunication 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".
[21] GSM 09.07 (ETS 300 604): "European digital cellular telecommunication 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)".
[22] GSM 09.08 (ETR 110): "European digital cellular telecommunication system
(Phase 2); Application of the Base Station System management Application Part
(BSSMAP) on the E-interface".
[23] GSM 09.10 (ETS 300 605): "European digital cellular telecommunication system
(Phase 2); Information element mapping between Mobile Station - Base Station
System and BSS - Mobile-services Switching Centre (MS - BSS - MSC)
Signalling procedures and the Mobile Application Part (MAP)".
[24] GSM 09.11 (ETS 300 606): "European digital cellular telecommunication system
(Phase 2); Signalling interworking for supplementary services".
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
[25] GSM 09.90 (ETR 111): "European digital cellular telecommunication system
(Phase 2); Interworking between Phase 1 infrastructure and Phase 2 Mobile
Stations (MS)".
[26] CCITT Series V Recommendations: "Data communication over the Telephone
network".
[27] CCITT Series X Recommendations: "Data communication networks".
[28] CCITT Recommendation X.25 "Interface between data terminal equipment
(DTE) and data circuit - terminating equipment (DCE) for terminals operating in
the packet mode and connected to public data networks by dedicated circuit".
[29] CCITT Recommendation X.150: "Data Communication Networks:Transmission,
Signalling and Switching, Network Aspects, Maintenance and Administrative
Arrangements".
[30] CCITT Recommendation V.25bis: "Automatic Calling and/or Answering
Equipment on the General Switched Telephone Network (GSTN) using the 100-
Series Interchange Circuits".
[31] CCITT Recommendation V.54: "Loop Test Devices for Modems".
[32] CCITT Recommendation V.110: "Support of data terminal equipments (DTEs)
with V-Series interfaces by an integrated services digital network".
[33] CCITT Recommendation I.460-I.464: "ISDN Overall Network Aspects and
Functions, User Network Interfaces".
[34] ETS 300 102-1: "Integrated Services Digital Network (ISDN); User-network
interface layer 3 specifications for basic call control".
[35] ETR 018: "Integrated Services Digital Network (ISDN), Application of the BC-
,HLC-,LLC-Information elements by terminals supporting ISDN services".
[36] ISO/IEC 6429: "Information technology - Control functions for coded character
sets".
1.3 Definitions and abbreviations
In addition to those below, abbreviations used in this specification are listed in GSM 01.04.
CALL PROC CALL PROCEEDING
CALL CONF CALL CONFIRMED
CONNACK CONNECT ACKNOWLEDGEMENT
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
2 ACCESS REFERENCE CONFIGURATION
Figure 1 presents the reference configuration for access to a GSM PLMN (see GSM 04.02).
MS
:<˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜>:
: �˜˜˜˜˜˜˜¿ : �˜˜˜˜˜˜˜˜˜˜˜¿
: ‡ MT0 ˆ˜˜¯˜˜· BSS/MSC ‡
: �˜˜˜˜˜˜˜� : �˜˜˜˜˜˜˜˜˜˜˜�
: �˜˜˜˜˜˜˜¿ �˜˜˜˜˜˜˜¿ : �˜˜˜˜˜˜˜˜˜˜˜¿
: ‡ TE1 ˆ˜˜¯˜˜· MT1 ˆ˜˜¯˜˜· BSS/MSC ‡
: �˜˜˜˜˜˜˜� : �˜˜˜˜˜˜˜� : �˜˜˜˜˜˜˜˜˜˜˜�
�˜˜˜˜˜˜˜¿ �˜˜˜˜˜˜˜¿ : �˜˜˜˜˜˜˜¿ : �˜˜˜˜˜˜˜˜˜˜˜¿
‡ TE2 ˆ˜˜¯˜˜· TA ˆ˜˜¯˜˜· MT1 ˆ˜˜¯˜˜· BSS/MSC ‡
�˜˜˜˜˜˜˜� : �˜˜˜˜˜˜˜� : �˜˜˜˜˜˜˜� : �˜˜˜˜˜˜˜˜˜˜˜�
�˜˜˜˜˜˜˜¿ : : �˜˜˜˜˜˜˜¿ : �˜˜˜˜˜˜˜˜˜˜˜¿
‡ TE2 ˆ˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜· MT2 ˆ˜˜¯˜˜· BSS/MSC ‡
�˜˜˜˜˜˜˜� : : �˜˜˜˜˜˜˜� : �˜˜˜˜˜˜˜˜˜˜˜�
: : :
R S Um
˜¯˜ = reference point
TE1 = ISDN terminal
TE2 = V- or X-type terminal
TA = Terminal Adaptor
BSS = Base Station System
MSC = Mobile Switching Centre
Figure 1: GSM PLMN Access Reference Configuration
Within the scope of this Specification the Mobile Termination MT0 means a fully integrated MS including
data terminal and its adaptation functions. MT1 includes ISDN terminal adaptation functions and MT2
includes CCITT V- or X-series terminal adaptation functions among other MT functions.
3 not used
4 not used
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
5 FUNCTIONS TO SUPPORT DATA SERVICES
The main functions of the MT to support data services are:
- functions to ensure conformity of terminal service requests to network capability
- physical connection of the reference points R and S
- flow control of signalling and mapping of user signalling to/from GSM PLMN access signalling
- rate adaptation of user data (see GSM 04.21)
- flow control of non-transparent user data and mapping of flow control for asynchronous data
services
- support of data integrity between the MS and the interworking function in the GSM PLMN
- end-to-end synchronization between terminals
- filtering of status information
- functions to support non-transparent bearer services e.g. termination of the Radio Link Protocol
(RLP) and the Layer 2 Relay function (L2R) (where applicable)
- terminal compatibility checking
- optional support of local test loops
In addition, functions to support autocalling and autoanswering are optionally specified in accordance with
CCITT Rec. V.25 bis (although the use of other autocalling/autoanswering procedures are not prohibited
provided that mapping in a functionally equivalent way to GSM 04.08 call control is also provided).
Other functional entities can be envisaged apart from the TAF. One of the physical interface to all these
functions is the DTE/DCE interface to the MT. Normally, this DTE/DCE interface is associated with the
TAF, if available. Therefore the access to any of these other functional entities, if implemented, via the
DCE/DTE interface must be triggered by appropriate command sequences which are described in the
applicable specifications (although the use of other procedures is not prohibited provided that mapping in a
functionally equivalent way is also provided). These command sequences can be issued by the DTE only
when the MT is in the appropriate command status and there is no data connection pending. They are
interpreted by an MT internal control function and result in an association of the DTE/DCE interface with
the addressed function, if available.
6 SUPPORT OF NON TRANSPARENT BEARER SERVICES
In order to support non transparent bearer services a Layer 2 Relay (L2R) function is included in the
mobile termination. The details of the particular L2R function for the different non transparent bearer
services are contained in the appropriate GSM 07-series Specification. This section describes the general
aspects of the L2R function.
The Layer 2 Relay (L2R) function provides for the reliable transportation of known, i.e. non transparent,
user protocols across the radio interface of a GSM PLMN. The L2R functions are located in the Mobile
Termination (MT) and the Interworking Function (IWF) associated with a Mobile Switching Centre (MSC).
The L2R uses the services provided by the Radio Link Protocol (RLP) to transport the non transparent
protocol information between the MS and the IWF.
6.1 Functions of the Layer 2 Relay
The complete protocol reference models for data and telematic services are described in GSM 03.10. The
subset of those protocol reference models relating to the L2R function is reproduced in Figure 2.
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
MS IWF
˜˜˜˜˜˜˜˜˜˜˜˜˜ Transparent higher layer protocol ˜˜˜˜˜˜˜˜˜˜˜˜˜
�˜˜˜˜˜˜˜˜˜¿ �˜˜˜˜˜˜˜˜˜¿
‡ L2R ˆ˜˜˜˜˜ L2R Protocol ˜˜˜˜· L2R ‡
˜ NTP ˜˜· �˜´˜˜˜· ˆ˜˜˜´˜¿ ˆ˜˜ NTP ˜˜
‡ ‡ ‡ ˆ˜ Radio Link Protocol ˜· ‡ ‡ ‡
ˆ˜˜˜· ˆ˜˜˜· ˆ˜˜˜· ˆ˜˜˜·
˜ IFP ˜˜· ‡ ‡ ˆ˜˜ IFP ˜˜
ˆ˜˜˜· ˆ˜˜˜·
NTP - Non Transparent Protocol
IFP - Interface Protocol
Figure 2
The Non Transparent Protocol (NTP) will normally be a layer 2 protocol for OSI conformant protocols or an
equivalent in the case of non OSI protocols. The Interface Protocol (IFP) will normally be a layer 1 protocol
for OSI conformant systems or equivalent for non OSI systems.
The L2R can be considered to consist of 3 sub-functions, see figure 3.
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¿
‡ ‡
‡ Relay Entity ‡
‡ ˆ˜˜˜˜˜˜˜˜˜˜˜
‡ ‡
‡ L2RP ‡
˜˜˜˜˜˜˜˜˜˜· NTP Entity ‡
‡ Entity �˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ ‡ ‡
‡ ‡ ‡ RLP ‡
‡ ‡ ‡ Entity ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜·
Figure 3
The 3 sub-functions are:
- A Non Transparent Protocol Entity
- A L2R Protocol Entity
- A Relay Entity
The NTP-entity interfaces the L2R to the IFP-entity and provides an interface to the particular NTP.
The L2RP-entity interfaces the L2R to the RLP-entity and provides an interface to the appropriate L2R
protocol.
The Relay-entity provides the mapping between the NTP-entity and the L2R-entity.
It should be noted that the inter-layer interfaces within the MS and the IWF and within the L2R will not be
specified by GSM, any description given is for explanatory purposes only and is not intended to indicate a
method of implementation. Therefore, the specification of the L2R is in terms of the peer-peer protocols.
Generally, the non transparent and interface protocols will be specified elsewhere, e.g. CCITT
Recommendation X.25 Layer 2 and 1. Thus the main specification for the L2R will consist of the L2R peer-
peer protocols.
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ETS 300 582: July 1995 (GSM 07.01 version 4.8.0)
6.2 Radio Link Services Used
The L2R function uses services defined in GSM Specification 04.22 (Radio Link Protocol).
6.3 Flow Control - General Description
A flow control active condition can take place under a number of circumstances.
- End to end flow control (DTE to DTE matter)
- Backpressure (buffers filling)
- Receive not ready (RLP condition)
It is possible that there will be an interaction between flow control active and inactive conditions in each
circumstances.
6.3.1 End to End Flow Control
A DTE may wish to send a flow control active condition to another DTE.
Provisions exists in the L2R entity to transfer a flow control active condition (sent by its associated DTE) to
the other L2R entity as soon as possible. This mechanism in the L2R entities allows such a flow control
condition to be put ahead of any queuing which exists in the L2R entities.
Such a mechanism avoids build up of data in buffers which can be undesirable.
The L2R entity, receiving a flow control active condition from its associated DTE, stops sending data to
that associated DTE immediately.
6.3.2 Back Pressure
The L2R and RLP entities have buffers which may become full to a predetermined threshold for a number
of reasons, e.g.severe radio fading, failure or slowness of DTE to react to end to end flow control, certain
RNR conditions. When this predetermined threshold is reached, a flow control active condition is sent to
the associated DTE which is then prevented from sending any data, subsequently, the flow control inactive
condition is sent to the associated DTE when the L2R or RLP entities have indicated that there is sufficient
free capacity in their buffers for data flow from the associated DTE to proceed.
The corresponding peer-layer procedure to assess the respective buffer conditions are a layer
management matter and are not dealt with here. It is also considered an implementation matter to ensure
that such procedure do not result in loss of data or considerable reduction in throughput.
6.3.3 Receive not Ready
When the RNR condition arises, an RLP indication is sent to the other RLP entity which in turn shall send a
flow control active condition to its associated L2R entity. That L2R entity shall then send a flow control
active condition to its associated DTE.
An RNR condition may result in the Execution of "back pressure" as mentioned under 6.3.2.
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7 STRUCTURE OF THE GSM 07-SERIES OF SPECIFICATIONS
The structure of the Specifications is as follows:
07.01 General on Terminal Adaptation Functions for Mobile Stations
07.02 Terminal Adaptation Functions for Services using Asynchronous Bearer Capabilities
This Specification defines the interfaces and terminal adaption functions integral to a MT
which enable the attachment of Asynchronous Terminals to a MT.
07.03 Terminal Adaptation Functions for Services using Synchronous Bearer Capabilities
This Specification defines the interfaces and terminal adaptation functions integral to a
MT which enable the attachment of Synchronous Terminals to a MT.
8 FUNCTIONS COMMON TO ALL INTERFACES
8.1 Synchronization of the Traffic Channel
As long as there is no connection between the traffic channel and the interface to the TE this interface
must be terminated in the appropriate way.
Prior to exposing the traffic channel of a GSM PLMN connection to transmission of user data, the
controlling entities of the connection have to assure of the availability of the traffic channel. This is done by
the so called synchronization process
- starting on the indication of "physical connection established" resulting from the PLMN inherent
outband signalling procedure. This indication is given on reception of the message CONNECT in
case of MOC, on reception of the message CONNACK in case of MTC and on reception of the
message MODIFY COMPLETE in case of in-call modification.
- ending by indicating the successful execution of this process to the controlling entity, which then
takes care of the further use of the inband information (data, status).
With respect to the TAF for the transparent bearer capability support the synchronization procedure is as
follows:
- sending of synchronization pattern 1/OFF (all data bits "1" / all status bits "OFF", all E-bits "1") to
the IWF
- searching for detection of the synchronization pattern 1/OFF received from the IWF. The value of
the bits E4-E7 shall not be checked
- holding CT106, 107 and 109 in the OFF condition
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note),
When the 1/OFF from the IWF has been recognized as a steady state the TAF continues sending the
synchronization pattern 1/OFF to the IWF unless a timer T (=500ms) expires. From this time the filtering
process according to section 8.2 applies and the information on the receiving lines CT106 and CT109 from
the IWF are directly mapped to the respective sending lines. The condition on CT107 will be changed from
"OFF" to "ON", the data bits received from the IWF are mapped to CT104, and CT103 is mapped to the
data bits sent towards the IWF.
During the synchronization process described above i.e. while the synchronization pattern is being sent by
the MT, the MT will not send the V.110 frame structure to the ISDN terminal. Once the timer T expires the
synchronization pattern will continue to be transmitted from the MT to the IWF, however, the MT will start
sending the V.110 frames received from the IWF to the ISDN terminal. The MT will start looking for the
ISDN frame alignment to be received from the ISDN terminal. On recognizing frame alignment the MT will
cease sending its synchronization pattern to the IWF and connect the ISDN terminal through to the IWF.
With respect to the TAF for non-transparent bearer capability support the synchronization procedure is as
follows:
- initiating the RLP link establishment by sending a RLP-SABM across the radio interface.
- holding CT106, 107, 109 in the OFF condition.
When the RLP link has been established, CT107 will be changed from "OFF" to "ON". From this time the
information from/to the RLP, including status changes, will be mapped by the L2R entity applicable to the
particular bearer capability. The MT will not send V.110 frame structure to the ISDN terminal and will not
start looking for ISDN frame alignment to be received from the ISDN terminal unless the RLP link has been
established. On recognizing frame alignment the information from/to the RLP will be mapped by the L2R
entity.
It should be noted that in a GSM PLMN V.-series and X.-series interfaces are only supported in full duplex
mode. Thus the call control phase can be mapped almost completely to the signalling procedure (the S-bits
during the call control phase are irrelevant). However, the "ready for data" condition (i.e. CT 106/109, in
the case of V.-series interface, and I-circuit, in the case of X.-series interface) is derived directly from the
traffic channel (see also filtering of channel information).
8.2 Filtering of Channel Control Information
8.2.1 General
The DTEs taken into account for the PLMN at the MS side conform to CCITT's DTE/DCE interface
specifications, which assume basically an error-free environment, i.e.
- limited distance, point-to-point local interconnection of the interface circuits for data and status
- steady state signalling.
The envisaged use of these DTEs in the PLMN environment leads to the exposure of these
"interconnections" to the PLMN radio channel. To assure proper operation even under these conditions
appropriate measures have to be taken. In the non transparent case the RLP satisfies the requirement for
both data and status lines.
NOTE:
- an idle frame sent by the BSS and received by the MS has the same pattern as the
synchronisation pattern 1/OFF
- at the moment when the message CONNECT (MOC) or CONNACK (MTC) is
received at the MS, it is guarantied that this pattern is received from the MSC/IWF with
the exception of a loss of frame synchronisation on the Abis interface
- the handling of frame stealing in case of 2400bit/s full rate data channels is
implementation dependent
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In the transparent case the
- data line aspects have to be dealt with end-to-end between the users, while
- status line aspects are of concern to the network, which are dealt with in the following.
8.2.2 Filtering Process to Be Applied
Filtering of channel control information is only relevant at the MS side in the transparent mode of operation.
By applying filtering measures the condition of a DTE/DCE control interchange circuit, for which the DTE
constitutes the information sink, will be preserved until another condition is signalled for an "integration
time" period by the channel control information (status bits) of the rate adaptation scheme.
The filtering mechanism is understood to reside between the rate adaptation function (information source)
and the DTE (information sink). It receives the unfiltered condition of the respective control interchange
circuit set according to the actual sequential appearance of the individual associated status bit and
forwards the filtered condition to the DTE.
The filtering process starts when the traffic channel synchronisation ends with the expiry of timer T.
V.-series interface
CT 106
In the transparent mode the remote inband control of this circuit is needed to support a modem retrain
procedure.
OFF-ON transition at the MS will authorize the DTE to send data; if wrongly set, loss of data may occur.
ON-OFF transition at the MS will cause the DTE to cease transmitting data; set wrongly may impair the
performance in connection usage.
CT 109
In the transparent mode the remote inband control of this circuit is needed to
- trigger the interpretation of received data
- indicate to the DTE the state of the connection.
OFF-ON transition at the MS will authorize the DTE to rely on the condition of the received data
interchange circuit, set wrongly may cause receipt of wrong data, while setting late may cause loss of
data.
ON-OFF transition at the MS
- will cause the DTE to cease receiving data
- may initiate release of the connection during a data phase by the DTE giving an ON-OFF transition
on circuit 108/2.
Setting this condition wrongly may cause loss of data and potentially release the connection.
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X.-series interface
I-circuit
The OFF-ON transition of this circuit in connection with the appropriate conditions of the other interchange
circuit will indicate the "ready for data" status of the connection. As received data may commence
immediately following this status change, the delay in conveying this condition shall be kept as short as
possible.
As a clear request/indication will be directly mapped to the PLMN outband signalling the ON-OFF
integration time should be rather long.
Filtering mechanism
A filtering mechanism shall be provided by an integration process on the SB and X datastreams carried in
the V.110 frame. The integration periods applied are:
V-series Transition Integration Status
period stream
CT 106 Off-On 1 s X
CT 106 On-Off 1 s X
CT 109 Off-On 200 ms SB
CT 109 On-Off 5 s SB
X-series Transition Integration Status
period stream
I-circuit Off-On 40 ms SB
I-circuit On-Off 5 s SB
The integration process shall ensure that the interchange circuits do not change state in response to
spurious transitions of the status bits during the integration period.
The integration process shall operate reliably with error characteristics as specified in GSM 05.05.
8.3 Terminal Compatibility Decision
The establishment of a mobile terminated connection depends on a positive decision on the terminal
compatibility. The Mobile Station (MS) contributes to this process by performing (depending on the
individual call set-up condition)
- a compatibility check
- the selection of the appropriate terminal function, and
- the indication of compatibility requirements to the PLMN
initiated by a call set-up request from the PLMN. The afore mentioned functions shall be carried out as
follows.
8.3.1 Compatibility Check
Annex B of GSM 04.08 applies, particularly paragraphs B.3, B.3.1 and B.3.2. As regards the therein
mentioned user-to-user compatibility checking the following applies:
When the calling user requests a service with user-to-user compatibility significance indicated by the
presence of HLC and LLC information element in the call set-up request, the MS shall check that the
service supported by the called user matches concerning the contents of the HLC/L
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