ETSI TS 148 002 V13.0.0 (2016-01)

ETSI TS 1148 002 V13.0.0 (201616-01)






TECHNICAL SPECIFICATIONION
Digital cellular telecocommunications system (Phahase 2+);
Basase Station System -
Mobile-services Swiittcching Centre (BSS - MSC) interface; in
IntInterface principles
(3GPP TS 48.0.002 version 13.0.0 Release 13 13)

R
GLOBAL SYSTTEME FOR
MOBILE COMMUUNNICATIONS

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3GPP TS 48.002 version 13.0.0 Release 13 1 ETSI TS 148 002 V13.0.0 (2016-01)



Reference
RTS/TSGG-0248002vd00
Keywords
GSM
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3GPP TS 48.002 version 13.0.0 Release 13 2 ETSI TS 148 002 V13.0.0 (2016-01)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or
GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables.
The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under
http://webapp.etsi.org/key/queryform.asp.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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3GPP TS 48.002 version 13.0.0 Release 13 3 ETSI TS 148 002 V13.0.0 (2016-01)
Contents
Intellectual Property Rights . 2
Foreword . 2
Modal verbs terminology . 2
Foreword . 5
1 Scope . 6
2 References . 7
3 Definitions and abbreviations . 7
4 Functional division between Base Station System (BSS) and MSC . 8
4.1 Terrestrial channel management . 8
4.1.1 Terrestrial channel allocation . 8
4.1.2 Blocking of terrestrial channels . 9
4.2 Radio channel management . 9
4.2.1 Channel configuration management . 9
4.2.2 Radio TCH management . 9
4.2.2.1 Radio channel allocation . 9
4.2.2.2 TCH radio link supervision . 9
4.2.2.3 Frequency hopping management . 9
4.2.2.4 Idle channel observation . 9
4.2.2.5 TCH power control . 10
4.2.2.6 TCH channel release . 10
4.2.3 BCCH CCCH management . 10
4.2.3.1 Scheduling of BCCH and CCCH messages . 10
4.2.4 DCCH Management . 10
4.2.4.1 DCCH link supervision . 10
4.2.4.2 DCCH channel release . 10
4.2.4.3 DCCH power control . 10
4.2.4.4 Radio Channel Allocation . 10
4.3 Resource indication . 10
4.4 Channel coding decoding . 10
4.5 Transcoding/rate adaptation . 11
4.6 Interworking function (data calls) . 11
4.7 Measurement information . 11
4.7.1 Measurement information reported from the MS . 11
4.7.2 Uplink measurement information . 11
4.7.3 Traffic information . 11
4.8 Handover . 11
4.8.1 Internal handover within one cell . 11
4.8.2 Internal handover between cells. 11
4.8.3 External handover . 12
4.8.3.1 Recognition that a handover is required for a radio reason . 12
4.8.3.2 Recognition that a handover is required for a traffic reason . 12
4.8.3.3 Decision of Target Cell . 12
4.8.3.4 Execution . 12
4.9 Mobility management . 12
4.10 Call control . 12
4.11 Security features . 12
4.11.1 User data confidentiality . 12
4.11.2 User identity confidentiality . 13
4.11.3 Signalling information confidentiality . 13
4.11.4 Authentication of users . 13
4.12 Global Text Telephony . 13
4.13 NAS Node Selection Function . 13
ETSI

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3GPP TS 48.002 version 13.0.0 Release 13 4 ETSI TS 148 002 V13.0.0 (2016-01)
5 Transcoder/rate adapter integration . 13
5.1 TDM based A-Interface . 13
5.2 IP based A-Interface . 13
6 Multiplexing of common and dedicated control channels. 14
7 Classes of signalling messages . 14
8 Support of services and features other than speech . 14
8.1 Data services . 14
8.2 Supplementary services . 14
9 Interface structures . 14
10 Operation and maintenance . 15
Annex A (informative): Remote Mobile Switching Unit (RMSU) . 16
A.1 Introduction . 16
A.2 Functions provided by the RMSU . 16
A.3 General requirements . 16
Annex B: (void) . 17
Annex C (informative): Change History . 18
History . 19

ETSI

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3GPP TS 48.002 version 13.0.0 Release 13 5 ETSI TS 148 002 V13.0.0 (2016-01)
Foreword
rd
This Technical Specification has been produced by the 3 Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
ETSI

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3GPP TS 48.002 version 13.0.0 Release 13 6 ETSI TS 148 002 V13.0.0 (2016-01)
1 Scope
The present document gives the principles on which the detailed interface specifications in the rest of the 3GPP TS
48.0xx series of Technical Specifications are based.
The set of fixed equipment accessed from the MSC through one particular instance of the interface will be later referred
to as a Base Station System (BSS). A BSS ensures the coverage of n cells, where n can be 1 or more.
The function of a BSS may be further subdivided into a control function, performed by one Base Station Controller
(BSC) and a transceiving function, performed by "n" Base Transceiver Station equipments (BTS), one for each cell.
However, the study of such a split is outside the scope of the 48.0xx series of Technical Specifications, where the BSS
will be considered as a whole.
The BSS-MSC interface defined in the 3GPP TS 48 series of Technical Specifications is designed to support a wide
range of possible architectures on both sides. Characteristics like location of the transcoders/rate adaptation to the MSS
or inside the BSS (either physically integrated into the transceivers or very near to the MSC) or the use of traffic or
signalling concentration at either side are left to the operators" choice. Annex A to the present document contains
guidance information concerning the use of remote mobile switching units, which for the purposes of the present
document are considered as part of the MSC.
The BSS-MSC interface is commonly called 'A-Interface'. It is subdivided into the Control Plane (signalling) and the
User Plane (traffic). Throughout this document the term 'MSC' is used to reflect both planes of the Mobile Core
Network, although in some architecture the Mobile Core Network is split into MSC-Server (MSC-S) and Media
Gateway (MGW).
Direct connection between two BSSs is not supported by this A-Interface.
This A-Interface may be based on
- TDM using 1 or more 2 048 kbit/s digital transmission system interfaces. Each 2 048 kbit/s interface provides
31*64 kbit/s channels which can be used for traffic (User Plane) or signalling (Control Plane) as the operator
requires, and/or
- IP supporting User Plane and/or Control Plane (SIGTRAN).The signalling is layered, terminology similar to that
in the OSI reference model is used in this series, however the layers referred to are not identical to the
equivalently named layer in the OSI model.
This A-Interface User Plane is defined at the boundary of the MSC and
- in case of TDM, it has a per channel bit rate of 64 kbit/s, but the net radio path traffic channel is at a rate of less
than 16 kbit/s. A speech transcoder or data rate adapter function is thus needed for the rate conversion. The
interface is designed such that the transcoding or rate adaptation function may be geographically situated at
either the MSC site or the BSS site, however the transcoder is considered to be part of the BSS
- in case of IP, it has a flexible channel bit rate, adapted to the payload size. The speech transcoding function can
be part of either the BSS or the Core Network or can be omitted (transcoding free operation), allowing e.g. for
use of both, PCM encoded speech and compressed speech, over the A-Interface. The data rate adapter function is
always located inside the BSS, using a 64kbit/s unrestricted digital interface (Clearmode) over IP.
The A-Interface has been designed around the aims of 3GPP TS 48.001 allowing each component and the system as a
whole to evolve.
ETSI

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3GPP TS 48.002 version 13.0.0 Release 13 7 ETSI TS 148 002 V13.0.0 (2016-01)
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including
a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same
Release as the present document.
[1] 3GPP TS 21.905: "Vocabulary for 3GPP Specifications".
[2] 3GPP TS 23.009: "Handover procedures".
[3] 3GPP TS 23.910: "Circuit switched data bearer services".
[4] 3GPP TS 43.020: "Security related network functions".
[5] 3GPP TS 44.018: "Mobile radio interface layer 3 specification; Radio Resource Control Protocol".
[6] 3GPP TS 48.001: Base Station System - Mobile services Switching Centre (BSS - MSC)
interface; General aspects".
[7] Void.
[8] 3GPP TS 48.006: "Signaling transport specification mechanism for the Base Station Subsystem –
Mobile-services Switching Centre (BSS - MSC) interface".
[9] 3GPP TS 48.008: "Mobile-services Switching Centre – Base Station System (MSC-BSS)
interface; Layer 3 specification".
[10] Void.
[11] Void.
[12] Void.
[13] Void.
[14] Void.
[15] Void.
[16] Void.
[17] Void.
[18] 3GPP TS 52.001: "Common aspects of GSM Network Management (NM)".
[19] 3GPP TS 23.236: " Intra-domain connection of Radio Access Network (RAN) nodes to multiple
Core Network (CN) nodes ".
3 Definitions and abbreviations
Abbreviations used in the present document are listed in 3GPP TS 21.905.
ETSI

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3GPP TS 48.002 version 13.0.0 Release 13 8 ETSI
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