1、 ETSI TS 1Evolved Universal TerresX2 genera(3GPP TS 36.4TECHNICAL SPECIFICATION136 420 V13.0.0 (2016LTE; restrial Radio Access Network (eral aspects and principles 6.420 version 13.0.0 Release 1316-01) k (E-UTRAN); ) ETSI ETSI TS 136 420 V13.0.0 (2016-01)13GPP TS 36.420 version 13.0.0 Release 13Refe
2、rence RTS/TSGR-0336420vd00 Keywords LTE 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 but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The pre
3、sent 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 ET
4、SI. 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
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6、tal.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 modif
7、ied 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. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are Trade Marks of ETSI registered for the benefit o
8、f 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 Association. ETSI ETSI TS 136 420 V13.0.0 (2016-01)23GPP TS 36.420 version 13.0.0 Release 13In
9、tellectual 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 R
10、ights (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,
11、 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
12、 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 G
13、SM, 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 t
14、he 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 136 420 V13.0.0 (2016-01)33GPP TS 36.420 version 13.0.0 Release 13Contents Intellectual Property Rights 2g3Foreword . 2
15、g3Modal verbs terminology 2g3Foreword . 5g31 Scope. . 6g32 References 6g33 Definitions, symbols and abbreviations . 6g33.1 Definitions 6g33.2 Abbreviations . 7g34 General aspects . 7g34.1 Introduction 7g34.2 X2 interface general principles . 7g34.3 X2 interface specification objectives 7g34.3.1 Gene
16、ral 7g34.3.2 Addressing of eNBs over the X2 interface . 7g34.4 X2 interface capabilities . 7g34.4.1 Radio application related signalling 7g34.4.2 X2 tunnels . 8g34.5 X2 interface characteristics 8g34.5.1 Uses of SCTP 8g34.5.1.1 General 8g35 Functions of the X2 interface . 8g35.1 Function list 8g35.2
17、 Function description . 9g35.2.1 Intra LTE-Access-System mobility support for ECM-CONNECTED UE . 9g35.2.1.1 Context transfer from source eNB to target eNB 9g35.2.1.2 Control of user plane transport bearers between source eNB and target eNB 9g35.2.1.3 Handover cancellation . 9g35.2.1.4 UE context rel
18、ease in source eNB . 9g35.2.1.5 Dual Connectivity . 9g35.2.2 Load management . 9g35.2.3 Inter-cell interference coordination . 9g35.2.3.1 Uplink interference load management 9g35.2.3.2 Downlink interference avoidance 9g35.2.4 General X2 management and error handling functions 10g35.2.4.1 Error indic
19、ation . 10g35.2.4.2 Reset 10g35.2.5 Trace functions . 10g35.2.6 Application level data exchange between eNBs . 10g35.2.7 Data exchange for self-optimisation . 10g36 X2 interface protocols and protocol structure 10g36.1 General . 10g36.2 Radio signalling protocols 11g36.2.1 X2AP protocol 11g36.3 User
20、 plane protocol 11g36.3.1 Tunnelling protocol GTP-U 11g37 Other X2 interface specifications . 11g37.1 E-UTRAN X2 interface: X2 layer 1 (TS 36.421). 11g37.2 E-UTRAN X2 interface: X2 signaling transport (TS 36.422) . 12g37.3 E-UTRAN X2 interface: X2 application protocol (X2AP) (TS 36.423) 12g37.4 E-UT
21、RAN X2 interface: X2 data transport (TS 36.424) 12g3ETSI ETSI TS 136 420 V13.0.0 (2016-01)43GPP TS 36.420 version 13.0.0 Release 137.5 Summary of E-UTRAN X2 interface Technical Specifications . 12g3Annex A (informative): Change history . 13g3History 14g3ETSI ETSI TS 136 420 V13.0.0 (2016-01)53GPP TS
22、 36.420 version 13.0.0 Release 13Foreword This Technical Specification has been produced by the 3rdGeneration 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 content
23、s 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 docum
24、ent 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 ETSI TS 136 420 V13.0.0 (2016-01)63GPP TS 36.420
25、 version 13.0.0 Release 131 Scope. The present document is an introduction to the TSG RAN TS 36.42x series of UMTS Technical Specifications that define the X2 interface. It is an interface for the interconnection of two E-UTRAN NodeB (eNB) components within the Evolved Universal Terrestrial Radio Ac
26、cess Network (E-UTRAN) architecture (TS 36.401 2). 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
27、 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 sam
28、e Release as the present document. 1 3GPP TR 21.905: “Vocabulary for 3GPP Specifications“. 2 3GPP TS 36.401: “Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Architecture description“. 3 3GPP TS 36.421: “Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 layer 1“. 4 3GPP
29、TS 36.422: “Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 signaling transport“. 5 3GPP TS 36.423: “Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 application protocol (X2AP)“. 6 3GPP TS 36.424: “Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 dat
30、a transport“. 7 IETF RFC 4960 (2007-09): “Stream Control Transmission Protocol“. 8 3GPP TS 36.300: “Evolved Universal Terrestrial Radio Access (E-UTRA), Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2“. 3 Definitions, symbols and abbreviations 3.1 Definitio
31、ns For the purposes of the present document, the terms and definitions given in TR 21.905 1 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 1. Dual Connectivity: Defined in TS 36.300 8. E-RAB: Defined in TS 3
32、6.401 2. X2 GW: Defined in TS 36.300 8. ETSI ETSI TS 136 420 V13.0.0 (2016-01)73GPP TS 36.420 version 13.0.0 Release 133.2 Abbreviations For the purposes of the present document, the abbreviations given in TR 21.905 1 and the following apply. An abbreviation defined in the present document takes pre
33、cedence over the definition of the same abbreviation, if any, in TR 21.905 1. ECM EPS Connection Management E-RAB E-UTRAN Radio Access Bearer MeNB Master eNB SeNB Secondary eNBX2-C X2 Control plane X2 GW X2 GateWay 4 General aspects 4.1 Introduction The interface allowing to interconnect eNBs with e
34、ach other is referred to as the X2 interface. 4.2 X2 interface general principles The general principles for the specification of the X2 interface are as follows: - the X2 interface should be open; - the X2 interface shall support the exchange of signalling information between two eNBs, in addition
35、the interface shall support the forwarding of PDUs to the respective tunnel endpoints; - from a logical standpoint, the X2 is a point-to-point interface between two eNBs within the E-UTRAN. A point-to-point logical interface should be feasible even in the absence of a physical direct connection betw
36、een the two eNBs. 4.3 X2 interface specification objectives 4.3.1 General The X2 interface specifications shall facilitate the following: - inter-connection of eNBs supplied by different manufacturers; - support of continuation between eNBs of the E-UTRAN services offered via the S1 interface; - sep
37、aration of X2 interface Radio Network functionality and Transport Network functionality to facilitate introduction of future technology. 4.3.2 Addressing of eNBs over the X2 interface - 4.4 X2 interface capabilities 4.4.1 Radio application related signalling The X2 interface provides capability to s
38、upport radio interface mobility and Dual Connectivity between eNBs, of UEs having a connection with E-UTRAN. ETSI ETSI TS 136 420 V13.0.0 (2016-01)83GPP TS 36.420 version 13.0.0 Release 134.4.2 X2 tunnels 4.5 X2 interface characteristics 4.5.1 Uses of SCTP 4.5.1.1 General The SCTP (IETF RFC 4960 7)
39、is used to support the exchange of X2 Application Protocol (X2AP) signalling messages between two eNBs A single SCTP association per X2-C interface instance shall be used, except when the X2 GW is used. Only when the X2 GW is used to connect one eNB to one or more specific eNB(s), all X2-C interface
40、 instances from that eNB to the relevant eNB(s) are carried over the same SCTP association from that eNB to the X2 GW, and over separate SCTP association(s) from the X2 GW to the relevant eNB(s). For X2-C interface instance(s) over one SCTP association one pair of stream identifiers shall be used fo
41、r X2-C common procedures and only a few pairs of stream identifiers should be used for X2-C dedicated procedures. Source-eNB communication context identifiers that are assigned by the source-eNB for X2-C dedicated procedures, and target-eNB communication context identifiers that are assigned by the
42、target-eNB for X2-C dedicated procedures, shall be used to distinguish UE specific X2-C signalling transport bearers. The communication context identifiers are conveyed in the respective X2AP messages. 5 Functions of the X2 interface 5.1 Function list The list of functions on the X2 interface is the
43、 following: - Intra LTE-Access-System Mobility Support for ECM-CONNECTED UE: - Context transfer from source eNB to target eNB; - Control of user plane transport bearers between source eNB and target eNB; - Handover cancellation; - UE context release in source eNB; - Dual Connectivity. - Load Managem
44、ent - Inter-cell Interference Coordination - Uplink Interference Load Management; - Downlink interference avoidance. - General X2 management and error handling functions: - Error indication; - Reset. - Application level data exchange between eNBs - Trace functions ETSI ETSI TS 136 420 V13.0.0 (2016-
45、01)93GPP TS 36.420 version 13.0.0 Release 13- Data exchange for self-optimisation 5.2 Function description 5.2.1 Intra LTE-Access-System mobility support for ECM-CONNECTED UE This function allows the eNB to handover the control of a certain UE to another eNB. 5.2.1.1 Context transfer from source eNB
46、 to target eNB This function allows transferring information required to maintain the E-UTRAN services for an UE in ECM-CONNECTED from source to target eNB. 5.2.1.2 Control of user plane transport bearers between source eNB and target eNB This function allows establishing and releasing transport bea
47、rers between source and target eNB to allow for data forwarding. At most one user plane transport bearer per E-RAB allocated to the UE may be established for relaying DL data received from the EPC from the source eNB to the target eNB. At most one user plane transport bearer per E-RAB allocated to t
48、he UE may be established for relaying the UL data received from the UE from the source eNB to the target eNB. 5.2.1.3 Handover cancellation This function allows informing an already prepared target eNB that a prepared handover will not take place. It allows releasing the resources allocated during a
49、 preparation. 5.2.1.4 UE context release in source eNB This function allows the target eNB to trigger the release of the resources allocated to the UE in the source eNB. 5.2.1.5 Dual Connectivity This function allows MeNB and SeNB to support Dual Connectivity. MeNB and SeNB manage establishment, modification and release of UE context at the SeNB, and controls user plane tunnels over X2. 5.2.2 Load management This function allows exchanging overload and traffic load information between eNBs, such that the eNBs can control the traffic loa
