Status of IMS-Based Next Generation Networks for Fixed Mobile Convergence

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Anissa Parker
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1 Status of IMS-Based Next Generation Networks for Fixed Mobile Convergence Prepared for: WOCC 2007 Fuchun Joseph Lin Chief Scientist Telcordia Technologies, Inc. April 28,

2 Outline Evolution to IMS-Based Next Generation Networks Mobile Networks (3GPP, 3GPP2, WLAN, WiMAX) Fixed Networks (DSL, Cable) IMS Technical Challenges Verizon Wireless A-IMS IMS Readiness and Its Impact to Legacy Telecommunications Systems Conclusion 2

3 IMS-Based Next Generation Networks Legacy mobile signaling networks IMS-SSF SGW Applications and Services HSS SLF BGCF BGCF IM CN Subsystem IP/Multimedia Networks OSA-SCS CSCF MGCF AS SGW MRFC MRFP MGW PSTN Mobile RANs UTRAN PDF IPCAN GGSN Packet-Cable 2.0 SGSN MSC DSL PS-Domain CS-Domain 3G Cellular 3

4 Evolution to IMS-Based Next Generation Networks (1) WiMAX CSN 1.5 Adopts IMS PacketCable 2.0 Adopts IMS ATIS NGN FG and IIF ITU-T FG NGN and IPTV ETSI TISPAN_NGN NGN Gap Analysis ITU-T NGN R1 TISPAN NGN R1 IPTV NGN-GSI IPTV NGN R2 3GPP Release 8 3GPP2 MMD 3GPP IMS 3GPP Release 5 IMS Phase 1 3GPP Release 6 IMS Phase 2 3GPP Release 7 IMS Phase 3 March 2003 December June 2004 March 2005 December 2005 December 2006

5 Evolution to IMS-Based Next Generation Networks (2) Cellular Fixed FMC 3GPP ATIS ITU-T IMS Specification Starting with Extended IMS from TISPAN NGN-FG NGN GSI ATIS (NA) ETSI (Europe) CCSA (China) TTA (Korea) ARIB (Japan) TTC (Japan) ETSI TISPAN NGN Extended IMS For Fixed Networks IETF Reqts OMA CableLabs PacketCable 2.0 WiMAX Forum NWG 1.5 NGN Based on IMS with Broadband support (e.g. xdsl) Has adopted IMS Has adopted IMS Has adopted IMS 5 Mobile

6 IMS in Mobile Networks (3GPP, 3GPP2, WLAN, WiMAX) 3GPP has IMS ownership and will continue evolve IMS to meet the needs of various access networks. 3GPP2 adopts IMS as the core of its Multi-Media Domain (MMD) architecture but adds CDMA2000 access specific changes. WLAN have been integrated with IMS in 3GPP Release 6 using a loosely coupled architecture. WiMAX follows the WLAN approach but adds WiMAX access specific changes to its IMS architecture. 6

7 IMS in 3GPP IMS Phase 1 (3GPP Release 5) Provisioning of IP-based multimedia services Call control and roaming to support IMS in UMTS Access Security for IMS Lawful interception Charging and OAM&P for IMS IMS Phase 2 (3GPP Release 6) IMS Conferencing IMS Messaging IMS Group Management Interworking with WLAN Additional SIP capabilities (e.g. forking) Interworking with non IMS SIP networks (IETF SIP, IPV4) Interworking between IMS and CS networks Interworking and migration scenario for IPv4 based IMS QoS improvements (Gq) Flow-Based Charging Presence IMS Phase 3 (3GPP Release 7) Fixed Broadband Access to IMS Emergency calls in PS and IMS End-to-end QoS Combining CS with IMS Policy Control Evolution and Charging Accommodation of requirements from WLAN Accommodation of requirements from DSL and Cable 7

8 IMS in 3GPP2 MMD MMD consists of the following: IMS (IP Multimedia Subsystem) Packet Data Subsystem (vs. GPRS in 3GPP) 3GPP2 IMS Added flexibility (e.g. placement of P-CSCF) Access network specific changes (e.g. QoS, Mobility) Supports alternate authentication schemes etc. 3GPP2 PDS AAA, Policy, and Security Functions Home Agent (HA) Foreign Agent (FA) PDSN (Packet Data Service Node) PCF (Packet Control Function) MMD Rev 0 in December 2003 MMD Rev A in November 2005 Now wrapping up MMD Rev B, starting Rev C. 8

9 IMS in WLAN and WiMAX Loosely Coupled Approach WLAN Access Network 3GPP AAA Server WAG IMS Core Network PDG IMS Home WiMAX Access Network CSN IWU CSN IWU CSN IWK Unit Provide local IP address management (DHCP, DNS) Provide NAT function WAG WLAN Access Gateway Provide access to IMS services Route packets via PLMN to PDG Perform accounting and policy enforcement PDG Packet Data Gateway Service authentication and authorization IP address allocation Policy enforcement and charging CSN WiMAX Connectivity Service Network 9

10 IMS in Fixed Networks (DSL, Cable) DSL Under NGN (Next Generation Network) Initiative ITU-T and ETSI TISPAN develop IMS suited for DSL networks. Both TISPAN and ITU-T NGN Release 1 (supported by IMS Phase 3 in 3GPP Release 7) was finished at the end of Release 2 has been ongoing since Cable Under PacketCable 2.0 Initiative, Cable Labs is defining an end-to-end architecture for providing real-time IP communication services based on IMS The goal is to extend cable s existing Internet Protocol service environment to accelerate the convergence of voice, video, data, and mobility technologies 10

11 IMS in TISPAN and ITU-T NGN Service Stratum Application Functions User Profile Functions O ther M ultim edia Components Streaming Services Service and Control Functions Legacy Terminals GW Network Access A ttachm ent Functions NAAF PSTN / ISDN Emulation IP M ultim edia Component &PSTN/ISDN including Simulation PST N /ISD N S im ulation Resource and Admission Control Functions RACF Other Networks Customer Networks NGN Terminals Customer End-user and Terminal Functions Functions Access Functions UNI Access Transport Functions Edge Functions Core transport Functions Transport Stratum FGNGN-OD NNI Source: ITU-T FGNGN 11

12 IMS in PacketCable 2.0 PacketCable integrated an IMS core into the cable architecture Cable-based provisioning, management, and accounting Client-managed NAT & Firewall Traversal Policy Control via PacketCable Multimedia Subscriber Management HSS SLF Session Control I-CSCF P-CSCF IP connectivity via DOCSIS Access Network S-CSCF Applications Application Servers GPRS/other GSM PSTN Interconnect via PacketCable 1.5 Interconnect with PacketCable 1.5 telephony clients (E-MTAs) Enhancements based upon cable requirements Cable clients 12 Handsets Source: CableLabs

13 IMS Technical Challenges Non-SIP applications - The lack of support for non-sip-based applications and products is the biggest concern. Security Both network and device security enhancements are required. Wireless VoIP - SIP needs to be optimized to reduce mobile VoIP latency. Verizon Wireless pointed out the above IMS shortcomings when it announced its A-IMS architecture initiative on 7/27/

14 Key A-IMS Concepts Policy Server is designed to coordinate overall network resource usage including both SIP and non-sip applications. Service Broker can handle interactions between SIP and non-sip applications. Security agent capabilities are extended to all network devices. Use Security Manager to manage the overall security policy of the network. Use Bearer Manager (Home Agent) to provide two IP addresses and two anchors for a mobile terminal, one in the home network and one in the visiting network. This dual anchoring concept allows latency-sensitive application such as VoIP to use the visited anchor, while other applications requiring service provider control use the home anchor. 14

15 IMS Readiness IMS R5 IMS/NGN Functionalities *IMS R6 *IMS R7/NGN R1 *IMS R8/NGN R2 Gaps Critical time for industry support Opportunities! IMS/NGN Specifications Converged Industry-wide implementation of IMS/NGN Diverged Opportunities: To prove business case and to narrow the gaps and ensure convergence to IMS/NGN Both fixed and mobile operators can leverage the standardized solution. Achieve True fixed mobile convergence. 15

16 IMS Impact to Legacy Telecommunications Systems IMS is set to eventually replace legacy telecommunications systems (LTS). But this will be evolutionary rather than revolutionary. Need to consider the co-existence of LTS and IMS for at least next five years. Keys to drive the evolution toward IMS/NGN include Service differentiators for new revenue Reduced operations and capital expense A smooth transition strategy 16

17 Conclusion IMS has been adopted by all major access technologies as the core network service architecture. However, not all technical challenges behind the practical applicability of IMS have been addressed. We believe the use of experimental IMS testbeds to discover and address these technical issues are very critical at this point of standards development. These testbeds can assist and enable smooth deployment of the IMS-Based Next Generation Networks that are not addressed in the standards specifications. 17

IMS in the Next Generation Network

Proceedings of the 11th WSEAS International Conference on COMMUNICATIONS, Agios Nikolaos, Crete Island, Greece, July 26-28, 2007 45 IMS in the Next Generation Network TATIANA KOVACIKOVA, PAVOL SEGEC, MILAN