1、 ETSI TS 1Digital cellular telecoBase Station Controller Lay(3GPP TS 48.0TECHNICAL SPECIFICATION148 056 V13.0.0 (2016communications system (Phar - Base Transceiver Station (interface; ayer 2 specification .056 version 13.0.0 Release 13GLOBAL SYSTEMOBILE COMMUN16-01) hase 2+); n (BSC - BTS) 13) TEM F
2、OR ICATIONSRETSI ETSI TS 148 056 V13.0.0 (2016-01)13GPP TS 48.056 version 13.0.0 Release 13Reference RTS/TSGG-0248056vd00 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
3、but non lucratif enregistre la Sous-Prfecture 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 versi
4、ons 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 spec
5、ific 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
6、 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
7、 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. DE
8、CTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM 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
9、 Association. ETSI ETSI TS 148 056 V13.0.0 (2016-01)23GPP TS 48.056 version 13.0.0 Release 13Intellectual 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
10、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 (ht
11、tps:/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, ess
12、ential 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 interp
13、reted 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
14、“, “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 ETSI TS 148 056 V13.0.0 (2016-01
15、)33GPP TS 48.056 version 13.0.0 Release 13Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 4g31 Scope 5g32 References 5g33 Definitions and abbreviations . 6g34 General description. 6g35 Functional contents 7g36 LAPD functions 7g36.1 Exceptions and modifica
16、tions. 7g36.1.1 Void 7g36.1.2 Command/Response field bit (C/R) 7g36.1.3 Service Access Point Identifier (SAPI) . 7g36.1.4 TEI for point-to-point data link connection 8g36.1.5 Commands and responses . 8g36.1.6 Exchange identification (XID) command/response 8g36.1.7 MDL-XID . 8g36.1.8 PH-DATA, PH DEAC
17、TIVATE and PH-ACTIVATE 8 g36.1.9 MPH-ACTIVATE, MPH-DEACTIVATE an MPH-INFORMATION 8g36.1.10 Priority indicator . 9g36.1.11 Terminal Endpoint Identifier (TEI) management procedures . 9g36.1.11.1 General 9g36.1.11.2 TEI assignment procedure . 9g36.1.11.3 TEI identity verify procedure 11g36.1.11.4 Forma
18、ts and codes. 11g36.1.12 Automatic negotiation of data link layer parameters 11g36.1.13 Establishment procedures . 11g36.1.14 N(S) sequence error 11g36.1.15 List of system parameters . 11g36.1.15.1 Timer T200 . 12g36.1.15.2 Maximum number of retransmissions (N200) 12g36.1.15.3 Maximum number of octe
19、ts in an information field (N201) . 12g36.1.15.4 Maximum number of transmission of the TEI identity request message (N202) 12g36.1.15.5 Maximum number of outstanding frames (K) . 12g36.1.15.6 Timer T201 . 12g36.1.15.7 Timer T202 . 12g36.1.15.8 Timer T203 . 12g36.1.16 Data link layer monitor function
20、 . 13g36.1.17 Miscellaneous . 13g3Annex A (informative): Change History 14g3History 15g3ETSI ETSI TS 148 056 V13.0.0 (2016-01)43GPP TS 48.056 version 13.0.0 Release 13Foreword This Technical Specification has been produced by the 3rdGeneration Partnership Project (3GPP). The contents of the present
21、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 wh
22、ere: 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
23、 incremented when editorial only changes have been incorporated in the document. ETSI ETSI TS 148 056 V13.0.0 (2016-01)53GPP TS 48.056 version 13.0.0 Release 131 Scope The present document specifies the link layer used for signalling on the A-bis interface between BSC and BTS. The use and general as
24、pects of the A-bis interface are described in 3GPP TS 48.051 and the interface aspects in 3GPP TS 48.052. The Link Access Procedure on the D-channel (LAPD) specification used on the A-bis interface in the GSM PLMN is a subset of the EN 300 125 which in turn has less options than the CCITT Recommenda
25、tion Q.921. This description contains first the protocol definitions and second the services provided by the layer 2 to the layer 3. 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. References are either spe
26、cific (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-spec
27、ific 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 48.051: “Base Station Controller - Base Transceiver Station (BSC - BTS) interface; General aspects“. 3 3GPP TS 48.052
28、: “Base Station Controller - Base Transceiver Station (BSC - BTS) interface; Interface principles“. 4 Void. 5 Void. 6 Void. 7 Void. 8 Void. 9 Void. 10 Void. 11 Void. 12 Void. 13 Void. 14 Void. 15 Void. 16 Void. 17 Void. 18 Void. ETSI ETSI TS 148 056 V13.0.0 (2016-01)63GPP TS 48.056 version 13.0.0 Re
29、lease 1319 CCITT Recommendation Q.921: “Integrated services digital network (ISDN) user-network interface - Data link layer specification“. 20 EN 300 125: “Integrated Services Digital Network (ISDN); User-network interface data link layer specification Application of CCITT Recommendations Q.920/I.44
30、0 and Q.921/I.441“. 3 Definitions and abbreviations Abbreviations used in the present document are listed in 3GPP TS 21.905. 4 General description The following information categories are supported by the procedures of this layer 2 Recommendation: - signalling (including Short Message Service (SMS)
31、information); - operation and maintenance; - layer 2 management. For each of these categories the BSC may have one or more layer 2 links to every TRX and BCF. The signalling links over the A-bis interface are addressed to the different units by Terminal Endpoint Identifiers (TEI). The same unit will
32、 normally have more than one functional entity. The logical links between different functional entities are identified by functional addresses, the Service Access Points Identifier (SAPI). Figure 1 shows the architectural model with different layer 2 links. A number of logical links may be multiplex
33、ed on each physical link. The same layer 2 logical link may not be distributed over more than one physical link. _ | _ | | | | | | | | _ | _ _ | | | |_RSL_SAPI_=_0_| |_| | | | | |_OML_SAPI_=_62_| |_| | | | | |_L2ML_SAPI_=_63_| |_| TRX |TEI 1 | | | | | |_| | | | |_| |_| |_| | |LAYER 2| | _ _ | | | _
34、| | |_| | | | | |_|_RSL_SAPI_=_0_| |_| | | | | |_OML_SAPI_=_62_| |_| TRX |TEI 2 | | | |_L2ML_SAPI_=_63_| |_| | | | T E I | | | | |_| | | | |_RSL_SAPI_=_0_| | _ | | | |_OML_SAPI_=_62_| |_| | | | | |_L2ML_SAPI_=_63_| |_| | | | |_| | |_| TRX |TEI 3 | | | | | |_| | | |MANAGE-| | |_| |_| | |MENT | _ | _
35、_ | | | |_OML_SAPI_=_62_| |_| | | | | |_L2ML_SAPI_=_63_| |_| BCF |TEI 4 | | |_| |_| | | | | | _ _ | _ | | | | | | _ _ | OML _ _ _ _SAPI = 62_ | |_| |TEI 65 | | | | _ _ | L2ML_ _ _ _SAPI = 63_ | |_| | | |_|_| | |_| |_| | | |_| Figure 4.1: An example of Logical Layer 2 links supported by three permane
36、nt and one semipermanent links ETSI ETSI TS 148 056 V13.0.0 (2016-01)73GPP TS 48.056 version 13.0.0 Release 135 Functional contents The basic functional content of the layer 2 protocol is: - transparent layer 2 links and time fill; - point-to-point dedicated layer 2 links addressing both physical en
37、tities and functional entities; - point-to-multipoint addressed links used for layer 2 management; - basic functions for TEI assignment and management; - basic priority functions; - basic supervision of links when not carrying traffic; - sequence control; - transmission error control; - control of e
38、rrors not recoverable by retransmission. 6 LAPD functions The LAPD functions as specified in EN 300 125 are applicable. However, the exceptions and modifications specified in the remainder of the present document shall be used. 6.1 Exceptions and modifications In the following headlines from EN 300
39、125 are kept and references are made to the corresponding clause of EN 300 125. 6.1.1 Void 6.1.2 Command/Response field bit (C/R) (Refer to EN 300 125, part 2, clause 3.3.2) In GSM PLMNs BSC represents the network side and TRX/BCF the user side of the interface. 6.1.3 Service Access Point Identifier
40、 (SAPI) (Refer to EN 300 125, part 2, clause 3.3.3) The SAPI values for the A-bis interface are as listed in table 6.1.3. ETSI ETSI TS 148 056 V13.0.0 (2016-01)83GPP TS 48.056 version 13.0.0 Release 13Table 6.1.3: Allocation of SAPI values and priority classes SAPI value Related layer 3 or layer man
41、agement entity Priority 0 Radio signalling procedures 2 1 Reserved for packet mode communications using Q.931 call control procedures (Not used in GSM PLMN) - 16 Reserved for packet communication conforming to X.25 level 3 procedures (Not used in GSM PLMN - 62 Operation and maintenance procedure 1 6
42、3 Layer 2 management procedures 1 All others Reserved for future standardization - 6.1.4 TEI for point-to-point data link connection (Refer to EN 300 125, part 2, clause 3.3.4.2). The remaining Terminal Endpoint Identifier (TEI) values are used for the point-to-point data link connections associated
43、 with the addressed Service Access Point (SAP). The range of TEI values shall be allocated as shown in table 6.1.4. Table 6.1.4: Allocation of TEI values TEI value User type 0-63 TEI assignment for fixed TRX and BCF addresses 64-126 TEI assignment for additional, TRX or BCF addresses NOTE: A BCF is
44、given a separate layer 2 link only if it is not integrated with a TRX. 6.1.5 Commands and responses (Refer to EN 300 125, part 2, clause 3.6.1) The XID command and response are not used. 6.1.6 Exchange identification (XID) command/response (Refer to EN 300 125, part 2, clause 3.6.12) This functional
45、ity is not used. 6.1.7 MDL-XID (Refer to EN 300 125, part 2, clause 4.1.1.9) This functionality is not used. 6.1.8 PH-DATA, PH DEACTIVATE and PH-ACTIVATE (Refer to EN 300 125, part 2, clauses 4.1.1.10 - 4.1.1.12) This functionality is not relevant. 6.1.9 MPH-ACTIVATE, MPH-DEACTIVATE an MPH-INFORMATI
46、ON (Refer to EN 300 125, part 2, clauses 4.1.1.13 - 4.1.1.15) ETSI ETSI TS 148 056 V13.0.0 (2016-01)93GPP TS 48.056 version 13.0.0 Release 13This functionality is not relevant. 6.1.10 Priority indicator (Refer to EN 300 125, part 2, clause 4.1.3.1) The different SAPIs are given the priority classes
47、as listed in table 1 when contending (with priority one as the highest). 6.1.11 Terminal Endpoint Identifier (TEI) management procedures (Refer to EN 300 125, part 2, clause 5.3) Due to the special assignment functions needed on the A-bis interface there are modifications and additions to the assignment procedures. The rest of clause 5.3 in EN 300 125, part 2, is kept if not stated otherwise. 6.1.11.1 General (Refer to EN 300 125, part 2, clause 5.3.1) TEI management for A-bis interface is based on the following procedural means: - a Subset
