1、 ETSI TS 123 236 V15.0.0 (2018-06) 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 15.0.0 Release 15) TECHNICAL
2、 SPECIFICATION ETSI ETSI TS 123 236 V15.0.0 (2018-06)13GPP TS 23.236 version 15.0.0 Release 15Reference RTS/TSGS-0223236vf00 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
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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. ETSI 2018. All rights reserved. DECTTM, PLUGTESTSTM, UM
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9、s registered and owned by the GSM Association. ETSI ETSI TS 123 236 V15.0.0 (2018-06)23GPP TS 23.236 version 15.0.0 Release 15Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information pertaining to
10、 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. La
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13、ty of ETSI, and conveys no right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This Technical Specification (TS) has
14、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 ref
15、erence 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
16、 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 123 236 V15.0.0 (2018-06)33GPP TS 23.236 version 15.0.0 Release 15Contents Intellectual Property Rights
17、 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 5g3Introduction 5g31 Scope 6g32 References 6g33 Definitions, symbols and abbreviations . 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
18、and Network Resource Identification 9g34.4 NAS Node Selection Function . 10g34.5 Load Balancing 11g34.5a Load Re-Distribution 12g34.5a.1 General 12g34.5a.2 Network Mode of Operation = 1 . 13g34.6 Mobility Management 13g34.7 Default CN node and Backwards Compatibility 13g34.8 Support of combined mobi
19、lity management procedures 14g34.8.1 Attach 14g34.8.2 Routing area update 14g34.9 VGCS/VBS Compatibility Issues . 14g34.10 Interactions with E-UTRAN. 14g35 Functional Description . 15g35.1 MS Functions . 15g35.2 RNC Functions . 15g35.2.1 Load Re-Distribution function in RNC . 16g35.3 BSC Functions 1
20、6g35.3.1 A interface mode . 16g35.3.2 Gb mode . 16g35.3.3 Iu mode . 17g35.3.4 Load Re-Distribution function in BSC . 17g35.4 MSC Functions . 17g35.4.1 TMSI Allocation . 17g35.4.2 Mobility Management and Handover/Relocation . 18g35.4.3 Backward Compatibility and Default MSC 18g35.4.4 Support of Combi
21、ned Procedures . 18g35.4.5 Load Re-Distribution function in MSC 18g35.5 SGSN Functions . 18g35.5.1 P-TMSI Allocation . 18g35.5.2 Mobility Management and Handover/Relocation . 18g35.5.3 Backward Compatibility and Default SGSN 19g35.5.4 Support of Combined Procedures . 19g35.5.5 CS Paging . 19g35.5.6
22、Load Re-Distribution function in SGSN . 19g36 Application Examples 19g36.1 Network configuration example 1 19g36.2 Network configuration example 2 20g3ETSI ETSI TS 123 236 V15.0.0 (2018-06)43GPP TS 23.236 version 15.0.0 Release 157 Specific Examples 21g37.1 Building blocks for signalling flows 21g37
23、.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 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 . 21g37.1.6 SGSN selecting MSC 21g37.2 Sig
24、nalling flow for Attach (Iu interface mode) 21g37.3 Signalling flows for Service Request (Iu interface mode) 24g37.3.1 Service Request initiated by MS . 24g37.3.2 Service Request initiated by network 25g37.4 Signalling flow for Routing Area Update (Iu interface mode) . 26g37.5 IMSI attach procedure
25、/ Location area update with IMSI 29g3Annex A (informative): Network configuration examples 32g3A.1 One city centre surrounded by residential areas . 32g3A.1.1 Assumptions . 32g3A.1.2. TMSI calculation 32g3A.2 3 Neighbouring large city centres 33g3A.3 Support of Dedicated Core Networks. 38g3Annex B (
26、informative): Change history . 40g3History 41g3ETSI ETSI TS 123 236 V15.0.0 (2018-06)53GPP TS 23.236 version 15.0.0 Release 15Foreword This Technical Specification has been produced by the 3rd Generation Partnership Project (3GPP). The contents of the present document are subject to continuing work
27、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 T
28、SG 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
29、 have been incorporated in the document. Introduction UMTS will build on the success of GSM and is likely to become even more widespread, increasing the importance of a flexible network structure to permit the different operational configurations in which these networks will be deployed. The require
30、ments 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 number of MSC servers or SGSNs increases the networks performance in terms of scalability, distributing the network load amongst the serving entities, and redu
31、cing the required signalling as the user roams. ETSI ETSI TS 123 236 V15.0.0 (2018-06)63GPP TS 23.236 version 15.0.0 Release 151 Scope This document 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 i
32、mpacts 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 overall solution is described, and the detailed impacts on the existing specifications are identified. The description of a broadly similar concept for E-UTRAN b
33、ased systems is not described in the document: instead, it is described in TS 23.401 22. NOTE: The specified solution impacts RAN nodes. In case 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 gu
34、ideline for connecting RAN nodes to multiple MSC servers. The reference model to which these procedures apply can be found within TS 23.002 1. Detailed architectural requirements within the subsystems are contained within the remainder of the 23 series of specifications e.g. the requirements for the
35、 Packet Switched (PS) domain are contained within TS 23.060 2 and the requirements for the Bearer Independent CS Core Network are contained in TS 23.205 14. 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. -
36、 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 (includi
37、ng 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 23.002: “Network Architecture“. 2 3GPP TS 23.060: “General Packet Radio Service (GPRS) Service description; Stage 2“. 3 3GPP TS 23.012: “Locati
38、on management procedures“. 5 3GPP TS 25.331: “Radio Resource Control (RRC) Protocol Specification“. 6 3GPP TS 25.301: “Radio interface protocol 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
39、 interface RANAP signalling“. 10 3GPP TS 25.410: “UTRAN Iu Interface: General Aspects and Principles“. 11 3GPP TS 23.228: “IP Multimedia Subsystem 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 -
40、Stage 2“. 14 3GPP TS 23.205: “Bearer Independent CS Core Network Stage 2“. 15 3GPP TR 25.931: “UTRAN Functions, examples on signalling procedures“. 16 GSM 08.18: “General Packet Radio Service (GPRS);Base Station System (BSS) -Serving GPRS Support Node (SGSN); BSS GPRS Protocol (BSSGP)“. 17 3GPP TS 4
41、8.008: “Mobile-services Switching Centre - Base Station System (MSC - BSS) interface; Layer 3 specification“. ETSI ETSI TS 123 236 V15.0.0 (2018-06)73GPP TS 23.236 version 15.0.0 Release 1518 3GPP TS 23.003: “Numbering, addressing and identification“. 19 3GPP TS 43.068: “Voice Group Call Service (VG
42、CS); Stage 2“. 20 3GPP TS 43.069: “Voice Broadcast Service (VBS); Stage 2“. 21 3GPP TS 23.251: “Network Sharing; Architecture and functional description“. 22 3GPP TS 23.401: “General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access“. 23
43、 3GPP TS 924: “Feasibility Study on NAS Node Selection Function above BSC/RNC“. 3 Definitions, symbols and abbreviations 3.1 Definitions For the 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
44、 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 serve a mobile station and subsequently route the traffic to the assigned network resource. Network Resource Identifier: A specific parameter used to identify
45、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/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
46、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 traffic 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
47、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/RNC shall upon reception temporarily store the MSC/VLR-identity. 5.3.3 Iu mode To support MSs in Iu mode the BSC provides the same functionality as described
48、under “RNC Functions“. 5.3.4 Load Re-Distribution function in 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-distribut
49、ion in progress should be excluded from the NAS Node Selection 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 mechanism 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 (
