IMS: Lessons Learned Brough Turner SVP & CTO
Tomorrow s Communications Network One core network with any access Based on IP Wireline and wireless transparency Standardized signaling based on extensions to IETF stds Access and bandwidth will become commodities, services are the differentiator IP Multimedia Subsystem (IMS) Per-session control to support per-application quality of service (QoS) guarantees and per-application billing But service creation environments not standardized Slide 2
IMS Story Convergence Traditional Services IMS Services TV Caller ID Phone Tools Push to Talk TV Caller ID Phone Tools Push to Talk Application Application Application Application Application Application Subscriber Data Media Functions Access Delivery OSS/ BSS Subscriber Data Media Functions Access Delivery OSS/ BSS Subscriber Data Media Functions Access Delivery OSS/ BSS Subscriber Data Media Functions IP Multimedia Subsystem OSS/ BSS Wireline Packet Cable Wireless Wifi WiMax Wireline Packet Cable Wireless Wifi WiMax Source: Team Analysis, Lucent Slide 3
IMS Business Justification Convergence (to IP) saves money Access to new (IP-based) applications provides new sources of revenue Per session control (of IP sessions) allows differential billing on a per-application basis But Must maintain current revenue streams Controlled migration, especially for profitable applications Slide 4
History of IMS and NGN 3GPP IMS R5 3GPP Release 4 Packet Cable 2.0 ATIS NGN FG ITU-T NGN FG TISPAN R1 3GPP2 MMD 3GPP IMS R6 2000 2001 2002 2003 2004 2005 2006 3GPP R4 Softswitching for circuit switched 3GSM networks 3GPP R5 SIP-based IP Multimedia Subsystem (IMS) introduced 3GPP R6 adds features and support for IMS over WLAN 3GPP IMS R7 3GPP R7 adds broadband / wireline access capabilities with participation from 3GPP2 (CDMA 2000), TISPAN (ETSI s NGN), ITU-T NGN Focus Grp, ATIS NGN Focus Grp, PacketCable Slide 5
3GPP R7/TISPAN IMS Architecture Slide 6
IMS Session (i.e. Call) Control CSCF = Call session control function, i.e. softswitch Slide 7
So Far, Only Used for New Applications! Most major mobile operators have deployed a SIP infrastructure of some sort CSCFs per strict IMS, or pre-ims softswitches In use for new applications like Push-to-talk (PTT) Fixed operators moving to softswitching for conventional voice, But Mobile voice calls still use circuit switching Slide 8
Long Term Parallels: IN & IMS Intelligent Network (IN) IP Multimedia System (IMS) Free operators from equipment provider lock-in Separate applications from basic call control Open protocols & APIs for (many) new applications Intelligent Network Application Successes 800/900 #s, Mobile (HLR), Pre-paid, Voice mail, 15 year summary: only a few applications, but very widely deployed Slide 9
Early IMS Applications Push-to-Talk Being deployed today, performance improving Add video during voice call, a.k.a. video sharing See what I see most common use of 3G video calling Video sharing awaits spread of appropriate handsets Fixed-mobile convergence (FMC) But initial deployments use circuit switching via UMA Instant messaging Mobile initiated communities? or AOL, Yahoo, MSN & QQ? Video ringback NMS 2008? Slide 10
IMS Application & Database Servers Primary Application Servers (AS) part of IMS network package Ericsson BEA WebLogic SIP Server (WLSS) Nokia-Siemens Ubiquity SIP Application Server (SIP A/S) Standard interfaces; vendor specific added capabilities Primary database is Home Subscriber Server (HSS) Extensible to support application data in theory Standard interfaces; vendor specific added capabilities Slide 11
Media in IMS Applications In IMS model, applications invoke shared, networkbased, Media Resource Function (MRF) Slide 12
Practical Deployments Likely to be different Generic MRF is announcement server; additional media capabilities available, but expensive Media resources scale with application, i.e. must deploy additional ports with each application Some applications require specialized media, e.g. video, wideband audio conferencing Rich media resources from application vendor Application vendor follows IMS specs offers to use existing MRF, but ends up selling application-specific MRF Slide 13
IMS Model MRF vs. Actual MRFs Network Announcement Server S-CSCF Media for a specific application AS MRFC MGW MRFP IMS Core Network Slide 14
Application Migration Example MyCaller Leading ringback tone solution Deployed in ~30 mobile operator networks Existing deployments via IN and other circuit techniques Migration stage one: IMS-enabled MyCaller Works with IMS and pre-ims SIP infrastructures Consistent with a variety of IMS configurations Migration stage two: Native IMS MyCaller Leverage standard IMS network elements to maximum possible extent Slide 15
MyCaller Service Architecture IN Customer Care Digital Asset Management Subscriber Profiling & Statistics Subscriber Access Management Web WAP Content Media Profile Info CSM Subscriber Info SMS IVR HLR OSS / BSS Service GW Subscriber Provisioning, Content Selection Wireless Wireless Network Network MSC MyCaller MMP Node Audio Audio ID Query MyCaller Subscriber Server SCP MyCaller Mobile Media Platform Slide 16
IMS-enabled MyCaller Component View HSS OSS / BSS Digital Asset Management Subscriber Profiling & Statistics Subscriber Access Management Subscriber Access (Web, WAP, IVR, SMS, MMS, J2ME) Cx (Diameter) Custom er Care Content Media Profile Info CSM Subscriber Info Proprietary IP Mechanism Service GW Subscriber Profiling Data Mining Trend Analysis S-CSCF Filter ISC(SIP) Network AS RBT Logic Proprietary IP Mechanism MyCaller (MRF & AS) RBT Logic RTP Mr (SIP) Slide 17
IMS-enabled MyCaller Components Network Application Server (e.g. BEA WLSS) B2BUA; Resilience and Redundancy RBT AS logic Partial RBT Logic connection routing (select MRF) MyCaller Intelligent Peripheral (MRF & AS) Partial RBT Logic subscriber preferences & music database SIP UA Server functionality; RTP Interface MyCaller CSM Provides XML/SOAP interface for HSS Provisioning and Billing through custom adapter Slide 18
IMS Native MyCaller Customer Care Content Digital Asset Management Subscriber Profiling & Statistics Subscriber Access Management Web WAP SMS Media Profile Info CSM Subscriber Info IVR Subscriber Provisioning, Content Selection Cx (Diameter) S-CSCF HSS Filter ISC(SIP) Sh OSS / BSS AS RBT Logic Non-IMS IP Mechanism Service GW Non-IMS IP Mechanism MRFC Non-IMS IP Mechanism MRFP RTP (BEA WLSS or equiv.) Mr (SIP) Slide 19
IMS Native MyCaller Components MyCaller CSM Provides XML/SOAP interface for HSS Provisioning and Billing through custom adapter Application Server MyCaller Subscriber Server functions Forward INVITE to MRFC with selected content file to play MRFC Media Resource Broker for AS Identifies which set of MRFPs have the needed content MRFP Media Player with appropriate content replica to meet < 50 ms incremental post dial delay timing Slide 20
IMS Application Summary Application logic Connection control via IMS application server (AS) IMS AS determined by network provider Augment with application-specific AS for complex and/or media rich applications Data storage HSS for subscriber data and session data Typically augmented with application-specific databases Media Leverage network MRF for simple announcements Provide application-specific MRFs for significant media Slide 21
IMS: Lessons Learned (so far) Early days, evolving specs Pre-IMS deployments, esp. on fixed networks 3GPP releases 6, 7 yet to come, i.e. many years of evolution Connection control focus Establish IP sessions, guarantee QoS, bill per session Many applications need additional IT infrastructure Rich media specialized databases Interactive dialogs (IVVR) additional AS & MRF functionality, e.g. VXML, speech, content caching Once connected, three-tier IT model still valid, i.e. 1) database, 2) business logic, 3) presentation Slide 22
IMS Status Questioning is over 70% of the service providers believe that IMS is important or essential to their business Trials underway 35 major operators with IMS trials underway Some partial deployments in commercial service Building on experience Operators talking about early IMS experience Areas of further work have been identified Slide 23
Thank You Brough Turner SVP & CTO NMS Communications rbt@nmss.com