1、 International Telecommunication Union ITU-T Y.2027TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (07/2012) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Frameworks and functional architecture models Functional architect
2、ure of multi-connection Recommendation ITU-T Y.2027 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects Y.300Y.39
3、9 Interfaces and protocols Y.400Y.499 Numbering, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Architecture, access, network capab
4、ilities and resource management Y.1200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 IPTV over NGN Y.1900Y.1999 NEXT GENERATION NETWOR
5、KS Frameworks and functional architecture models Y.2000Y.2099Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Numbering, naming and addressing Y.2
6、300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Packet-based Networks Y.2600Y.2699 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 FUTURE NETWORKS Y.3000Y.3499 CLOUD COMPUTING Y.3500Y.3999 For furt
7、her details, please refer to the list of ITU-T Recommendations. Rec. ITU-T Y.2027 (07/2012) i Recommendation ITU-T Y.2027 Functional architecture of multi-connection Summary Recommendation ITU-T Y.2027 describes the functional architecture of multi-connection taking into account the requirements pro
8、vided in Recommendation ITU-T Y.2251 and the next generation network (NGN) functional architecture as provided in Recommendation ITU-T Y.2012. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.2027 2012-07-29 13 Keywords Access control layer, access layer, application layer, coordinati
9、on, functional architecture, heterogeneous access, multi-connection, multi-connection architecture, NGN heterogeneous access, NGN, session control layer. ii Rec. ITU-T Y.2027 (07/2012) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of t
10、elecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing tel
11、ecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the
12、 procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a
13、 telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all
14、 of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIG
15、HTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by IT
16、U members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this
17、may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T
18、Y.2027 (07/2012) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 2 4 Abbreviations and acronyms 2 5 Conventions 3 6 Overview of the multi-connection architecture 3 6.1 General architecture 3 6.2 High level
19、function descriptions . 5 6.3 Functional entities 8 6.4 Reference points . 11 7 Multi-connection architecture in relation to the NGN architecture 12 8 Security considerations . 14 Appendix I The evolvement of multi-connection architecture . 15 Appendix II Mapping of baseline to 3GPP EPC/IMS 17 Appen
20、dix III Mapping of baseline to next generation hotspot (NGH)/IMS . 18 Appendix IV Information procedures of multi-connection 19 IV.1 Initiating/adding a new connection 19 IV.2 Removing a connection 20 IV.3 IP flow mobility 21 IV.4 Service composition during call establishment 23 IV.5 Service decompo
21、sition during call establishment 24 IV.6 Service decomposition with QoS policy control 25 IV.7 Subscriber attaches to the access network 26 IV.8 Policy control procedure . 27 Bibliography. 28 Rec. ITU-T Y.2027 (07/2012) 1 Recommendation ITU-T Y.2027 Functional architecture of multi-connection 1 Scop
22、e As defined in ITU-T Y.2251, multi-connection functionality provides capabilities to the user equipment and network to support simultaneous attachment to multiple access technologies. Furthermore, it controls and coordinates media sessions and components through multiple access technologies. The us
23、er experience depends on the access technologies provided: high throughput, low delay, high security, etc. Multi-connection enables users to utilize either one of the available access technologies, or to utilize several at the same time. It is recognized that both operators and users will benefit fr
24、om the harmonization of multiple connections, such as efficient utilization of network bandwidth, load balancing, high reliability of connection and continuity of services. This Recommendation describes the functional architecture of multi-connection in terms of the overall functional requirements a
25、nd the high-level overview of the multi-connection framework itself. The objective of this Recommendation is to develop the functional architecture, definitions and capabilities of the relative functional entities, and to describe the relationship between the multi-connection functional architecture
26、 and the NGN functional architecture ITU-T Y.2012. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommen
27、dations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly pu
28、blished. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T Y.2012 Recommendation ITU-T Y.2012 (2010), Functional requirements and architecture of next generation networks. ITU-T Y.2251 Recommendation ITU-T Y.2251
29、 (2011), Multi-connection requirements. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 functional entity ITU-T Y.2012: An entity that comprises an indivisible set of specific functions. Functional entities are logical concepts, while g
30、roupings of functional entities are used to describe practical, physical implementations. 3.1.2 mediated services ITU-T Y.2012: Services that are based on intermediate service stratum facilities provided by one or more service providers. 3.1.3 multi-connection ITU-T Y.2251: The functionality which p
31、rovides capability to the user equipment (UE) and network to maintain more than one access network connection simultaneously. NOTE 1 All connections are coordinated to provide service to higher layer entities. NOTE 2 In a multi-connection communications at least one UE is required to be a multi-conn
32、ection UE. 2 Rec. ITU-T Y.2027 (07/2012) 3.1.4 non-mediated services ITU-T Y.2012: Services that are not based on intermediate service stratum facilities provided by any service provider. 3.2 Terms defined in this Recommendation This Recommendation defines the following term: 3.2.1 multi-connection
33、user equipment (MUE): A user equipment which can support two or more network connections simultaneously under the control of a network enhanced for multi-connection capability. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: 2G Second Generation 3G Thi
34、rd Generation AAA Authentication Authorization Accounting AC-FE Access Control FE ADSL Asymmetrical Digital Subscriber Line AN Access Network AP Access Point API Application Program Interface BSS Base Station Subsystem CS Circuit Switched EPC Evolved Packet Core FE Functional Entity FTP File Transfe
35、r Protocol HO Handover IF Interface IMS IP Multimedia Subsystem IP Internet Protocol ISP Internet Service Provider LTE Long Term Evolution MAS-F Multi-connection Application Support Function MC-ARCH Multi-connection Architecture MC-FE Multi-connection Coordination FE MMF Multi-connection Media Funct
36、ion MPC-FE Multi-connection Policy Control FE MR-FE Multi-connection Registration FE MSISDN Mobile Subscriber International ISDN / PSTN Number MTC-FE Multi-connection Terminal Control FE MUE Multi-connection UE Rec. ITU-T Y.2027 (07/2012) 3 MUP-FE Multi-connection User Profile FE NGH Next Generation
37、 Hotspot NGN Next Generation Network OSI Open System Interconnect reference model P2P Peer to Peer PC Personal Computer PS Packet Switched QoE Quality of Experience QoS Quality of Service SCF Service Control Functions SDP Session Description Protocol SIP Session Initial Protocol SUE Single connectio
38、n UE UE User Equipment UMTS Universal Mobile Telecommunications System VoIP Voice over IP VPN Virtual Private Network WBA Wireless Broadband Alliance WFA Wi-Fi Alliance Wi-Fi Wireless Fidelity WiMAX Worldwide Interoperability for Microwave Access WLAN Wireless Local Area Network 5 Conventions None.
39、6 Overview of the multi-connection architecture 6.1 General architecture The multi-connection architecture (MC-ARCH) enhances the NGN to support the ability of multiple concurrent sessions from a single UE in a coordinated manner. In order to achieve this, NGNs and UEs require the addition of new fu
40、nctions. The general architecture for multi-connection includes the following major functions, as shown in Figure 6-1: 1) Deployment of the multi-connection access technology policy and maintain information (such as traffic, usage duration, bandwidth, connection status, etc.) of the available connec
41、tions for MUEs; 2) Manage connections to initiation, transfer, release and update; 3) Provide mobility related services; 4) Provide flow-based management related services; 4 Rec. ITU-T Y.2027 (07/2012) 5) Provide session continuity for applications/services; 6) Provide QoS and relevant policy contro
42、l; 7) Manage multi-connection applications with proper access information statically or dynamically; 8) Support authentication, authorization and accounting (AAA) functions for multi-connection services and assist AAA related events in each access technology; 9) Support mechanisms for service compos
43、ition and decomposition which allow separation of one session of the relevant service (e.g., audio/video service) into several flows and vice versa; 10) Improve application performance by utilising available access technologies. Y.2027(12)_F6-1ApplicationsMulti-connectionapplication support function
44、Signal enhancedIn MC OtherMulti-connectioncontrol functionMulti-connectionmedia functionTransport functionMUEService control functionFigure 6-1 Overview of multi-connection architecture Figure 6-2 shows how an MUE and MC-ARCH enhanced network can align with the OSI layering. It also highlights that
45、MC-ARCH introduces new functions in user equipment and network nodes supporting multi-connection. Rec. ITU-T Y.2027 (07/2012) 5 Y.2027(12)_F6-2(1)(1)(1)(1)(n)(n)(n)(n)(n)(n)(n)(n)(1)(1)(1)(1)MUE MC-ARCHOSI L5-7e.g., multiple SIPregistrations usingIMPU/IMPITechnology independentidentifiers:OSI L4e.g.
46、, multiple SCTP bindingsTechnology independentidentifiers:OSI L3e.g., multiple HoAusing DSMIPv6,PMIPv6, GTPtunnel, NBIFOM etc.Technology independentidentifiers:OSI L1-2e.g., GSM, UMTS,LTE, Wi-Fi,WiMAX etc.e.g., multiple CoAsTechnology specificidentifiers:MC-TERMINALCONTROLMC-applicationsupport FECon
47、nection-less Connection-orientedMC-applicationsupport FEService control FE Service control FEUDP SCTP TCPAccess controlIP(DSMIPv6)Access controlIPSecPDCP/RLC/MAC/RFLLC/MAC/RFPeer protocolentitiesPeer protocolentitiesPeer protocolentitiesPeer protocolentitiesMC-applicationsupport FEAccess controlServ
48、ice controlFEAccess networkMC-REGISTRATIONMC-COORDINATIONCONTROLMC-USERPROFILEMC-POLICY CONTROLRTPSIP FTPMC - Media controlFigure 6-2 Functional entities supporting multi-connection architecture Figure 6-2 assumes, as an example, that the MUE has two concurrent ongoing sessions: The first session is
49、 a SIP based communication. In this instance, the SIP based application is enhanced for multi-connection since the service flow is decomposed between UMTS and Wi-Fi. In particular, the flow related to SIP signalling is carried over UMTS while the user plane is transported over Wi-Fi using UDP/RTP. The second session is a FTP session over Wi-Fi. In this case, the FTP application is not enhanced for multi-connection. The functional entities shown in yellow, support multi-connection, both in the UE and netw
