ETSI TS 148 052 V13.0.0 (2016-01)

ETSI TS 1148 052 V13.0.0 (201616-01)






TECHNICAL SPECIFICATIONION
Digital cellular telecocommunications system (Phahase 2+);
Base Station Controller r - Base Transceiver Station (n (BSC - BTS)
interface;
IntInterface principles
(3GPP TS 48.0.052 version 13.0.0 Release 13 13)

R
GLOBAL SYSTTEME FOR
MOBILE COMMUUNNICATIONS

---------------------- Page: 1 ----------------------
3GPP TS 48.052 version 13.0.0 Release 13 1 ETSI TS 148 052 V13.0.0 (2016-01)



Reference
RTS/TSGG-0248052vd00
Keywords
GSM
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: +33 4 92 94 42 00  Fax: +33 4 93 65 47 16

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
http://portal.etsi.org/tb/status/status.asp
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© European Telecommunications Standards Institute 2016.
All rights reserved.

TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.
TM
3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3GPP TS 48.052 version 13.0.0 Release 13 2 ETSI TS 148 052 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

---------------------- Page: 3 ----------------------
3GPP TS 48.052 version 13.0.0 Release 13 3 ETSI TS 148 052 V13.0.0 (2016-01)
Contents
Intellectual Property Rights . 2
Foreword . 2
Modal verbs terminology . 2
Foreword . 4
1 Scope . 5
2 References . 5
3 Definitions and abbreviations . 6
3.1 Definitions . 6
3.2 Abbreviations . 6
4 General . 6
5 Functional division between BSC and BTS . 7
5.1 General . 7
5.2 Terrestrial channel management . 7
5.3 Radio channel management . 7
5.3.1 Channel configuration management . 7
5.3.2 SDCCH (Stand alone DCCH) and TCH management . 8
5.3.2.1 Frequency hopping management . 8
5.3.2.2 Channel selection, link supervision and channel release . 8
5.3.2.3 Power control . 8
5.3.2.4 Idle channel observation . 8
5.3.3 BCCH/CCCH management . 8
5.3.4 Random access . 8
5.3.5 Channel coding/decoding . 8
5.3.6 Transcoding/rate adaption . 9
5.3.7 Timing advance . 9
5.3.8 Radio resource indication . 9
5.3.9 Measurements . 9
5.3.10 LAPDm functions (Layer 2) . 9
5.3.11 Paging . 9
5.3.12 Handover . 9
5.3.13 Encryption. 10
5.3.14 Mobility management and call control . 10
6 Transcoding/rate adaption and multiplexing . 11
6.1 Transcoding/rate adaption in BTS . 11
6.2 Transcoding/rate adaption outside BTS . 11
7 Interface structures . 12
7.1 Communication channels . 12
7.2 Signalling links . 12
7.3 Signalling model . 13
Annex A (informative): Change History . 17
History . 18

ETSI

---------------------- Page: 4 ----------------------
3GPP TS 48.052 version 13.0.0 Release 13 4 ETSI TS 148 052 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

---------------------- Page: 5 ----------------------
3GPP TS 48.052 version 13.0.0 Release 13 5 ETSI TS 148 052 V13.0.0 (2016-01)
1 Scope
The use and general aspects of the A-bis interface are given in 3GPP TS 48.051.
The present document gives the principle basis for the rest of the specifications specifying the interface between the
Base Station Controller, BSC, and the Base Transceiver Station, BTS, with its transceivers, TRX. These components
together form the Base Station System, BSS. (The interface between MSC and the BSS is specified in 3GPP TS 48.001
and 3GPP TS 48.020).
The intention with this interface is to get a unified way of connecting remotely located BTSs/TRXs to a BSC allowing
for the interconnection of BSCs and BTSs/TRXs from different manufacturers.
In order to keep the BTS as simple as possible, BTS contains only those functions which have to recide close to the
radio interface.
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 TR 21.905: "Vocabulary for 3GPP Specifications".
[2] 3GPP TS 48.001: "Base Station System - Mobile services Switching Centre (BSS - MSC)
interface; General aspects".
[3] 3GPP TS 48.002: "Base Station System - Mobile-services Switching Centre (BSS - MSC)
interface Interface principles".
[4] Void.
[5] 3GPP TS 48.006: "Signalling transport mechanism specification for the Base Station System -
Mobile-services Switching Centre (BSS-MSC) interface".
[6] Void.
[7] 3GPP TS 48.020: "Rate adaption on the Base Station System - Mobile-services Switching Centre
(BSS-MSC) interface".
[8] 3GPP TS 48.051: "Base Station Controller - Base Transceiver Station (BSC-BTS) interface;
General aspects".
[9] 3GPP TS 48.058: "Base Station Controller - Base Transceiver Station (BSC-BTS) interface;
Layer 3 specification".
[10] 3GPP TS 48.060: "Inband control of remote transcoders and rate adaptors for full rate traffic
channels".
[11] 3GPP TS 48.061: "Inband control of remote transcoders and rate adaptors for half rate traffic
channels".
[12] Void.
[13] 3GPP TS 23.002: "Network Architecture".
ETSI

---------------------- Page: 6 ----------------------
3GPP TS 48.052 version 13.0.0 Release 13 6 ETSI TS 148 052 V13.0.0 (2016-01)
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Base Station System (BSS): system of base station equipment (transceivers, controllers, etc.) which is viewed by the
MSC through a single interface as defined by the 3GPP TS 48.0xx series of recommendations, as being the entity
responsible for communicating with Mobile Stations in a certain area. The radio equipment of a BSS may cover one or
more cells. A BSS may consist of one or more base stations. If an internal interface according to the 3GPP TS 48.05x
series at recommendations is implemented, then the BSS shall consist of one Base Station Controller (BSC) and several
Base Transceiver Stations (BTSs).
NOTE: The functionality is described in 3GPP TS 48.001.
Base Station Controller (BSC): network component in the PLMN with the functions for control of one or more Base
Transceiver Stations (BTSs).
Base Transceiver Station (BTS): network component which serves one cell, and is controlled by a Base Station
Controller. The BTS can consist of one or more TRXs with or without common control equipment.
Cell: See 3GPP TS 23.002.
Transceiver (TRX): in the GSM PLMN is the functional entity which supports the 8 basic radio channels of the same
TDMA-frame.
Base Control Function (BCF): functional entity which handles common control functions within a BTS,
e.g. frequency hopping sequences etc.
At a multi BTS site, one of the BCFs can also be choosen to perform functions common to the site (e.g. external alarms,
power supply, time base).
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in 3GPP TR 21.905 apply.
4 General
3GPP TS 48.001 and 3GPP TS 48.020 specify the functional split and interface between MSC and the Base Station
System, BSS, the A- interface.
The BSS can be further subdivided into one BSC controlling one or more BTSs, each consisting of one or more TRXs.
The interface treated by the present document is the interface between a BSC and a BTS. It is denoted the A-bis-
interface.
The A-bis-interface is capable of supporting three different internal BTS configurations:
- one single TRX;
- a collection of TRXs where all are served by a common physical connection;
- a collection of TRXs, each served by its own physical connection.
ETSI

---------------------- Page: 7 ----------------------
3GPP TS 48.052 version 13.0.0 Release 13 7 ETSI TS 148 052 V13.0.0 (2016-01)
Figure 4.1 shows some possible configurations.
                    BSS
         <----------------------------------------->
         |    +-----+   A-bis   +-----+
              |   +-------- ┼-------| TRX | BTS1
         |    |   |        + - - |
              |   |        | BCF |
         |    |   |        +-----+
              |   |        +-----+
         |    |   |        | TRX |
              |   |   A-bis   + - - |
         |    |   +-------- ┼-------| TRX | BTS2
              |   |        + - - |
         |    |   |        | TRX |
              |   |        + - - |
         |    |   |        | BCF |
              |   |        +-----+
+-----+    A |    |   |        +- - -+
| MSC +-------- ┼-----------| BSC |   A-bis   |+---+|
+-----+      |    |   +-------- ┼--------|TRX|
              |   |        |+---+|
         |    |   |        |+---+|
              |   +-------- ┼--------|TRX|
         |    |   |        |+---+| BTS3
              |   |        |+---+|
         |    |   +-------- ┼--------|TRX|
              |   |        |+---+|
         |    |   |        |+---+|
              |   +-------- ┼--------|BCF|
         |    |   |        |+---+|
              +-----+        +-- - +

Figure 4.1: BSS Subdivision and Interfaces
The present document is based on the use of digital transmission system interfaces, either at 2 048 kbit/s or at 64 kbit/s.
Furthermore, the use of a subrate of 16 kbit/s and/or 8 kbit/s is supported for coded speech or rate adapted data.
This interface will support the transcoder positioned either inside or outside BTS. In the latter case, remote control
(synchronisation) of the transcoder is used.
5 Functional division between BSC and BTS
5.1 General
In Technical Specification 3GPP TS 48.001 the functional division between MSC and BSS is described. This clause
describes the further subdivisi
...