1、 ETSI TS 123 236 V14.0.0 (2017-05) Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Intra-domain connection of Radio Access Network (RAN) nodes to multiple Core Network (CN) nodes (3GPP TS 23.236 version 14.0.0 Release 14) TECHNICAL
2、 SPECIFICATION ETSI ETSI TS 123 236 V14.0.0 (2017-05)13GPP TS 23.236 version 14.0.0 Release 14Reference RTS/TSGS-0223236ve00 Keywords GSM,LTE,UMTS 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
3、Association 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
4、 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 ke
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6、spx 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 photocopyin
7、g 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 2017. A
8、ll rights reserved. DECTTM, 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. oneM2M logo is protected for the benefit of it
9、s Members GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI TS 123 236 V14.0.0 (2017-05)23GPP TS 23.236 version 14.0.0 Release 14Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The
10、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
11、 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 (o
12、r 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 th
13、eir 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 p
14、resent 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 deliverab
15、les except when used in direct citation. ETSI ETSI TS 123 236 V14.0.0 (2017-05)33GPP TS 23.236 version 14.0.0 Release 14Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 5g3Introduction 5g31 Scope 6g32 References 6g33 Definitions, symbols and abbreviations
16、. 7g33.1 Definitions 7g33.2 Symbols 7g33.3 Abbreviations . 7g34 General Description 8g34.1 Iu Flex Technical Requirements . 8g34.2 Overview 8g34.3 Pool-Area and Network Resource Identification 10g34.4 NAS Node Selection Function . 10g34.5 Load Balancing 11g34.5a Load Re-Distribution 12g34.5a.1 Gener
17、al 12g34.5a.2 Network Mode of Operation = 1 . 13g34.6 Mobility Management 13g34.7 Default CN node and Backwards Compatibility 14g34.8 Support of combined mobility management procedures 14g34.8.1 Attach 14g34.8.2 Routing area update 14g34.9 VGCS/VBS Compatibility Issues . 15g34.10 Interactions with E
18、-UTRAN. 15g35 Functional Description . 15g35.1 MS Functions . 15g35.2 RNC Functions . 16g35.2.1 Load Re-Distribution function in RNC . 16g35.3 BSC Functions 16g35.3.1 A interface mode . 16g35.3.2 Gb mode . 17g35.3.3 Iu mode . 18g35.3.4 Load Re-Distribution function in BSC . 18g35.4 MSC Functions . 1
19、8g35.4.1 TMSI Allocation . 18g35.4.2 Mobility Management and Handover/Relocation . 18g35.4.3 Backward Compatibility and Default MSC 18g35.4.4 Support of Combined Procedures . 18g35.4.5 Load Re-Distribution function in MSC 18g35.5 SGSN Functions . 19g35.5.1 P-TMSI Allocation . 19g35.5.2 Mobility Mana
20、gement and Handover/Relocation . 19g35.5.3 Backward Compatibility and Default SGSN 19g35.5.4 Support of Combined Procedures . 19g35.5.5 CS Paging . 20g35.5.6 Load Re-Distribution function in SGSN . 20g36 Application Examples 20g36.1 Network configuration example 1 20g36.2 Network configuration examp
21、le 2 20g3ETSI ETSI TS 123 236 V14.0.0 (2017-05)43GPP TS 23.236 version 14.0.0 Release 147 Specific Examples 21g37.1 Building blocks for signalling flows 21g37.1.1 RAN node selecting CN node in A interface mode 21g37.1.2 RAN node selecting CN node in Gb interface mode 21g37.1.3 RAN node selecting CN
22、node in Iu interface mode 21g37.1.4 New CN node selecting old CN node . 21g37.1.5 Old CN node selecting new CN node . 22g37.1.6 SGSN selecting MSC 22g37.2 Signalling flow for Attach (Iu interface mode) 22g37.3 Signalling flows for Service Request (Iu interface mode) 24g37.3.1 Service Request initiat
23、ed by MS . 24g37.3.2 Service Request initiated by network 25g37.4 Signalling flow for Routing Area Update (Iu interface mode) . 27g37.5 IMSI attach procedure / Location area update with IMSI 30g3Annex A (informative): Network configuration examples 33g3A.1 One city centre surrounded by residential a
24、reas . 33g3A.1.1 Assumptions . 33g3A.1.2. TMSI calculation 33g3A.2 3 Neighbouring large city centres 34g3A.3 Support of Dedicated Core Networks. 39g3Annex B (informative): Change history . 41g3History 42g3ETSI ETSI TS 123 236 V14.0.0 (2017-05)53GPP TS 23.236 version 14.0.0 Release 14Foreword This Te
25、chnical Specification has been produced by the 3rd 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-release
26、d 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
27、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. Introduction UMTS will build on the success of GSM and is likely to become even more widespread, incr
28、easing the importance of a flexible network structure to permit the different operational configurations in which these networks will be deployed. The requirements to have a RNC or BSC controlled by a single MSC server or SGSN lead to certain limitations. Allowing the BSCs and RNCs to connect to a n
29、umber of MSC servers or SGSNs increases the networks performance in terms of scalability, distributing the network load amongst the serving entities, and reducing the required signalling as the user roams. ETSI ETSI TS 123 236 V14.0.0 (2017-05)63GPP TS 23.236 version 14.0.0 Release 141 Scope This do
30、cument covers the details for the Intra Domain Connection of RAN Nodes to Multiple CN Nodes for GERAN and UTRAN based systems. In particular, it details the impacts to GSM and UMTS systems and the stage 2 procedures for the support of connecting a RNC or BSC to multiple MSC servers or SGSNs. The ove
31、rall solution is described, and the detailed impacts on the existing specifications are identified. The description of a broadly similar concept for E-UTRAN based systems is not described in the document: instead, it is described in TS 23.401 22. NOTE: The specified solution impacts RAN nodes. In ca
32、se an upgrade of radio networks is not performed, the solutions for deploying NNSF functionality above RAN nodes described in TR 23.924 23 may be used as a guideline for connecting RAN nodes to multiple MSC servers. The reference model to which these procedures apply can be found within TS 23.002 1.
33、 Detailed architectural requirements within the subsystems are contained within the remainder of the 23 series of specifications e.g. the requirements for the Packet Switched (PS) domain are contained within TS 23.060 2 and the requirements for the Bearer Independent CS Core Network are contained in
34、 TS 23.205 14. 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 re
35、ference, 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 docum
36、ent. 1 3GPP TS 23.002: “Network Architecture“. 2 3GPP TS 23.060: “General Packet Radio Service (GPRS) Service description; Stage 2“. 3 3GPP TS 23.012: “Location management procedures“. 5 3GPP TS 25.331: “Radio Resource Control (RRC) Protocol Specification“. 6 3GPP TS 25.301: “Radio interface protoco
37、l architecture“. 7 3GPP TS 25.303: “UE functions and inter-layer procedures in connected mode“. 8 3GPP TR 21.905: “3G Vocabulary“. 9 3GPP TS 25.413: “UTRAN Iu interface RANAP signalling“. 10 3GPP TS 25.410: “UTRAN Iu Interface: General Aspects and Principles“. 11 3GPP TS 23.228: “IP Multimedia Subsy
38、stem Stage 2“. 12 3GPP TS 43.051: “GSM/EDGE Radio Access Network (GERAN) overall description (Stage 2)“. 13 3GPP TS 23.153: “Out of Band Transcoder Control - Stage 2“. 14 3GPP TS 23.205: “Bearer Independent CS Core Network Stage 2“. 15 3GPP TR 25.931: “UTRAN Functions, examples on signalling procedu
39、res“. 16 GSM 08.18: “General Packet Radio Service (GPRS);Base Station System (BSS) -Serving GPRS Support Node (SGSN); BSS GPRS Protocol (BSSGP)“. ETSI ETSI TS 123 236 V14.0.0 (2017-05)73GPP TS 23.236 version 14.0.0 Release 1417 3GPP TS 48.008: “Mobile-services Switching Centre - Base Station System
40、(MSC - BSS) interface; Layer 3 specification“. 18 3GPP TS 23.003: “Numbering, addressing and identification“. 19 3GPP TS 43.068: “Voice Group Call Service (VGCS); Stage 2“. 20 3GPP TS 43.069: “Voice Broadcast Service (VBS); Stage 2“. 21 3GPP TS 23.251: “Network Sharing; Architecture and functional d
41、escription“. 22 3GPP TS 23.401: “General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access“. 23 3GPP TS 924: “Feasibility Study on NAS Node Selection Function above BSC/RNC“. 3 Definitions, symbols and abbreviations 3.1 Definitions For t
42、he purposes of the present document, the terms defined in TR 21.905 8 apply: CN node: for the purpose of this specification, and unless otherwise stated, a CN node is either an MSC or an SGSN. NAS node selection Function: The function used to assign specific network resources (i.e. MSC or SGSN) to s
43、erve a mobile station and subsequently route the traffic to the assigned network resource. Network Resource Identifier: A specific parameter used to identify the CN node assigned to serve a mobile station. Non-broadcast LAI/RAI: Each CN node in a pool have to be assigned one unique non-broadcast LAI
44、/RAI that it use in case it want to be offloaded. Each CN node in the pool has to be aware of the non-broadcast LAI/RAI assigned to the other CN nodes in the pool, because in case of re-distribution the target CN node will retrieve data (e.g. IMSI, security context, MM e.g. the possible downlink tra
45、ffic can be equally shared between the SGSNs, or the share of each SGSN can be proportional to the capacity of the SGSN. In case a MSC sends a paging-request with IMSI via Gs-interface the SGSN has to add the MSC/VLR-identity to the paging-request message. The NAS node selection function in the BSC/
46、RNC shall upon reception temporarily store the MSC/VLR-identity. ETSI ETSI TS 123 236 V14.0.0 (2017-05)183GPP TS 23.236 version 14.0.0 Release 145.3.3 Iu mode To support MSs in Iu mode the BSC provides the same functionality as described under “RNC Functions“. 5.3.4 Load Re-Distribution function in
47、BSC When the BSC receives a message with a null-NRI it uses the NAS Node Selection Function for selecting a CN node where to forward the message. This is also done for all messages with random TLLIs (Gb-mode). CN node(s) with re-distribution in progress should be excluded from the NAS Node Selection
48、 algorithm in the BSC. This is done by O&M configuration in the BSC. 5.4 MSC Functions 5.4.1 TMSI Allocation Every MSC is configured with its one or more specific NRI (O&M). One of these specific NRIs is part of every temporary identity (TMSI) which the MSC assigns to an MS. The TMSI allocation mech
49、anism in the MSC generates TMSIs which contain one of the specific NRIs in the relevant bit positions. An NRI has a flexible length between 10 and 0 bits (0 bits means the NRI is not used and the feature is not applied). The use of the bits not used to encode the NRI is implementation dependent (e.g. to extent the TMSI space). An MSC applying “Intra Domain Connection of RAN nodes to multiple CN nodes” shall allocate TMSIs to the served MSs. 5.4.2 Mobility Management and Handover/Relocation For MAP signalling be
