1、 ETSI TR 125 901 V7.0.0 (2007-06)Technical Report Digital cellular telecommunications system (Phase 2+);Universal Mobile Telecommunications System (UMTS);Network Assisted Cell Change (NACC) from UTRAN to GERAN;Network side aspects(3GPP TR 25.901 version 7.0.0 Release 7)GLOBAL SYSTEM FOR MOBILE COMMU
2、NICATIONSRETSI ETSI TR 125 901 V7.0.0 (2007-06) 1 3GPP TR 25.901 version 7.0.0 Release 7 Reference RTR/TSGR-0325901v700 Keywords GSM, 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 Associat
3、ion but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice Individual copies of the present document can be downloaded from: http:/www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perc
4、eived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should
5、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 servic
6、es: http:/portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2007. All rights reserved.
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8、rganizational Partners. ETSI ETSI TR 125 901 V7.0.0 (2007-06) 2 3GPP TR 25.901 version 7.0.0 Release 7 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
9、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
10、server (http:/webapp.etsi.org/IPR/home.asp). 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 ma
11、y be, or may become, essential to the present document. Foreword This Technical Report (TR) 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
12、 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. ETSI ETSI TR 125 901 V7.0.0 (2007-06) 3 3GPP TR 25.901 version 7.0.0 Release 7 Contents Intel
13、lectual Property Rights2 Foreword.2 Foreword.5 1 Scope 6 2 References 6 3 Definitions, symbols and abbreviations .6 3.1 Definitions6 3.2 Symbols6 3.3 Abbreviations .7 4 Introduction 7 5 Requirements7 6 Study Areas 8 6.1 UTRAN NACC signalling architecture8 6.1.1 General8 6.1.2 Solution 1: (P)SI store
14、d by the SRNC 8 6.1.2.1 General description .8 6.1.2.2 Analysis of the solution.9 6.1.3 Solution 2: (P)SI stored by the local RNC9 6.1.3.1 General description .9 6.1.3.2 Analysis of the solution.10 6.1.4 Solution 3: O 2 presented to TSG for approval; 3 or greater indicates TSG approved document unde
15、r 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 TR 125 901 V7.0.0 (2007-06) 6 3GPP TR 25.901 versio
16、n 7.0.0 Release 7 1 Scope This present document is for the 3GPP Release 6 Work Item “Network Assisted Cell Change Network Side Aspects.“. The purpose of the present document is to aid TSG RAN WG3 to standardise the signalling of relevant GERAN information during cell re-selection across the relevant
17、 UTRAN interfaces. This document is intended to gather all information in order to compare the solutions and to draw a conclusion on the way forward. This document is a living document, i.e. it is permanently updated and presented to TSG-RAN meetings. 2 References The following documents contain pro
18、visions 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 refe
19、rence, 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 TS 44.060: “3rd Generation Partnership Project; Technical
20、 Specification Group GSM/EDGE Radio Access Network; General Packet Radio Service (GPRS); Mobile Station (MS) - Base Station System (BSS) interface; Radio Link Control/Medium Access Control (RLC/MAC) protocol“. 2 3GPP TS 44.901: “3rdGeneration Partnership Project:; Technical Specification Group GSM/E
21、DGE Radio Access Network; External Network Assisted Cell Change“. 3 3GPP TR 21.905: “Vocabulary for 3GPP Specifications“. 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply. Local RNC: the local RNC(s) to a giv
22、en cell or BSS is/are the RNC(s) with cells which are neighbouring to the GERAN cell or BSC. Remote RNC: an RNC is remote to a given GERAN cell or BSS if none of its cells are neighbours of the GERAN cell or BSS. 3.2 Symbols For the purposes of the present document, the following symbols apply: Gb I
23、nterface between the BSS and the 2G SGSN Gn Interface between two GSNs in the same PLMN ETSI ETSI TR 125 901 V7.0.0 (2007-06) 7 3GPP TR 25.901 version 7.0.0 Release 7 3.3 Abbreviations Applicable abbreviations can be found in 3. For the purposes of the present document, the following abbreviations a
24、pply: BSSGP Base Station Subsystem GPRS Protocol DRNC Drift RNC GERAN GSM/EDGE Radio Access Network NACC Network Assisted Cell Change PSI Packet System Information RAN Radio Access Network RIM RAN Information Management RNC Radio Network Controller SI System Information SRNC Serving RNC 4 Introducti
25、on At the 3GPP TSG RAN #19 meeting, the Work Item Description on “Network Assisted Cell Change from UTRAN to GERAN Network Aspects“ was approved. In todays GPRS networks (without NACC), cell re-selection can causes a service interruption in the region of 4 8 seconds, which obviously has an impact on
26、 the user experience. Similar interruption times can be expected in mixed UMTS and GPRS networks, during UE cell re-selection from UTRAN to GERAN. Consequences of this: e.g. TCP applications may time-out at cell change and suffer from the slow-start mechanism, streaming applications may stop at cell
27、 change due to client buffer depletion. All such problems will lead to an unacceptable user experience. This “Network Assisted Cell Change“ feature has already been introduced in the GERAN specifications and the appropriate changes have been to the RLC/MAC protocol 1 within Release 4. Additional enh
28、ancements were approved in Release 5 in order to exchange (Packet) System Information between BSSs, so that NACC can work across BSS boundaries. Currently, there are procedures defined on the Gb and Gn interfaces to enable signalling of GERAN SI/PSI between BSSs. This RAN Information Management (RIM
29、) mechanism was defined initially for the use of NACC, although in a manner that could be extended for applications other than NACC. It consists of the following messages: - RAN INFORMATION REQUEST - from Source BSS to Target BSS requests GERAN SI/PSI. - RAN INFORMATION from target BSS to source BSS
30、 analogous to the Information Exchange over Iur and includes GERAN SI/PSI for one or more GERAN cells. - RAN INFORMATION ACKNOWLEDGE from Source BSS to Target BSS. - RAN INFORMATION ERROR - to inform about e.g. message syntax errors. In Release 5, TSG RAN approved the provision of the GERAN (P)SI me
31、ssages in the CELL CHANGE ORDER FROM UTRAN message. In order for this feature to work successfully, a standardised method is required to signal relevant GERAN information across the relevant UTRAN interfaces. 5 Requirements The standardisation of NACC from UTRAN to GERAN shall meet the following req
32、uirements: 1) The impact to the Gb and Gn interfaces shall be minimised. ETSI ETSI TR 125 901 V7.0.0 (2007-06) 8 3GPP TR 25.901 version 7.0.0 Release 7 6 Study Areas 6.1 UTRAN NACC signalling architecture 6.1.1 General Three possible mechanisms have been identified to gain access to the GERAN SI/PSI
33、 at the SRNC, whilst minimising the impacts on the existing Gb/Gn procedures: 1) The (P)SI is stored by the SRNC. 2) The (P)SI is stored by the local RNC 3) O b) towards one or more (S)RNCs when the local RNC receives an update from a GERAN BSS of the (P)SI for one or more GERAN cells. 6.2.2 Use of
34、RANAP or O b) OR, (corresponding to 2b) the RIM procedure messages are sent in a container inside messages of the existing Information Transfer procedure messages over the Iu interface. In this case, an INFORMATION TRANSFER REQUEST message would need to be created to contain the GERAN RAN INFORMATIO
35、N REQUEST message. When considering this question it should be noted that it is not seen as feasible to deconstruct the BSSMAP/RANAP message fully in the SGSN and construct a corresponding RANAP/BSSMAP message. This would have a higher impact on the SGSN implementation, with no extra gain, apart fro
36、m the fact that the RNC-ID would not be transferred in the RANAP message. 7 Agreements and associated Contributions The main text of the document should start here, after the above clauses have been added. 7.1 UTRAN NACC signalling architecture The mechanism used to gain access to the GERAN SI/PSI a
37、t the SRNC is such that the (P)SI will be stored by the local RNC. 7.2 Format of RIM messages GERAN does not adapt RIM messages to the target system and are routed via the CN without interpretation. The RNC alone needs to send and receive BSSGP messages within a container within the RANAP message. 7
38、.3 Exchange of Information over Iu The transfer of RIM information over the Iu from UTRAN, will be performed using a new RANAP procedure Direct Information Transfer. This generic Class 2 RANAP procedure has been designed such that it will transfer information from the RNC to the CN or vice versa, in
39、 unacknowledged mode maintaining the previously agreed RIM principles. 7.4 Exchange of Information over Iur The transfer of RIM information over the Iur between the SRNC and the DRNC will be performed using an existing RANAP R5 procedure RNSAP Information Exchange following an appropriate modificati
40、on/addition to the procedure. 8 Specification Impact & associated Change Requests This section is intended to list the affected specifications and the related agreed Change Requests. It also lists the possible new specifications that may be needed for the completion of the Work Task. ETSI ETSI TR 12
41、5 901 V7.0.0 (2007-06) 163GPP TR 25.901 version 7.0.0 Release 7 8.1 TS 25.401 UTRAN Overall Description 8.1.1 Impacts GERAN System Information Retrieval is introduced as an additional UTRAN function, as is RAN Information Management as an additional function related to radio resource management and
42、control. 8.1.2 List of Change Requests Refer to http:/www.3gpp.org/ftp/tsg_ran/TSG_RAN/TSGR_24/Docs/ZIP/RP-040182.ZIP. 8.2 TS 25.410 UTRAN Iu Interface: General Aspects and Principles 8.2.1 Impacts GERAN System Information Retrieval is introduced as an Iu Mobility Management function. 8.2.2 List of
43、Change Requests Refer to http:/www.3gpp.org/ftp/tsg_ran/TSG_RAN/TSGR_24/Docs/ZIP/RP-040182.ZIP. 8.3 TS 25.413 UTRAN Iu interface RANAP signalling 8.3.1 Impacts A generic Class 2 RANAP procedure (bi-directional i.e. UL and DL) Direct Information Transfer - has been introduced in RANAP to enable the t
44、ransfer of RIM-PDU for the NACC feature initially, and thereafter for future uses if/when they present themselves. 8.3.2 List of Change Requests Refer to http:/www.3gpp.org/ftp/tsg_ran/TSG_RAN/TSGR_24/Docs/ZIP/RP-040182.ZIP. 8.4 TS 25.420 UTRAN Iurinterface general aspects and principles 8.4.1 Impac
45、ts The exchange of information over the Iu of UTRAN and GERAN information has been included as a function of the Iur. 8.4.2 List of Change Requests Refer to http:/www.3gpp.org/ftp/tsg_ran/TSG_RAN/TSGR_24/Docs/ZIP/RP-040182.ZIP. ETSI ETSI TR 125 901 V7.0.0 (2007-06) 173GPP TR 25.901 version 7.0.0 Rel
46、ease 7 8.5 TS 25.423 UTRAN Iur interface RNSAP signalling 8.5.1 Impacts In the case that the CRNC is not the SRNC, and the SRNC would like to request NACC information, the Information Exchange Procedure has been modified such that the SRNC can request NACC related data for one or several GSM cells.
47、8.5.2 List of Change Requests Refer to http:/www.3gpp.org/ftp/tsg_ran/TSG_RAN/TSGR_24/Docs/ZIP/RP-040182.ZIP. 9 Project Plan 9.1 Schedule Date Meeting Scope expected Input expectedOutput Sept 2003 RAN#21 RAN Approval TR Approved Mar 2004 RAN#23 RAN Approval TR Approved June 2004 RAN#24 RAN Approval
48、TR Approved 9.2 Work Task Status Planned Date Milestone Status ETSI ETSI TR 125 901 V7.0.0 (2007-06) 183GPP TR 25.901 version 7.0.0 Release 7 Annex A: Change history Change history Date TSG # TSG Doc. CR Rev Subject/Comment Old New June 2004 TSG-RAN#24 RP-040186 Presentation of TR for information -
49、1.0.0 June 2004 TSG-RAN#24 Approved at TSG RAN #24 and placed under Change Control 1.0.0 6.0.0 September 2004 TSG-RAN#25 RP-040307 001 - Tidy Up CR for TR 25.901 (NACC) 6.0.0 6.1.0 June 2007 TSG-RAN#36 Upgrade to Release 7 6.1.0 7.0.0 ETSI ETSI TR 125 901 V7.0.0 (2007-06) 193GPP TR 25.901 version 7.0.0 Release 7 History Document history V7.0.0 June 2007 Publication
