Multimedia Gateways & H.248/ MEGACO

1. Multimedia Gateways & H.248/ MEGACO ITU Workshop on IP Networking & MEDIACOM-2004 April 26, 2001 Presented by- Clifford Sayre, Lucent Technologies

2. Multimedia Gateways • This presentation is the joint work of several teams: • NTT DoCoMo • Takashi Suzuki - (ITU-T SG 16 delegate) • NTT DoCoMo Communications Laboratories USA • Muhammad Mukarram Bin Tariq • Shahid Shoaib • Lucent Technologies • Clifford Sayre - (ITU-T SG 16 delegate)

3. Overview • Introduction to IMT-2000 & New Capabilities • Emerging Wireless Multimedia Applications • H.324M/ 3G-324M Standard for Wireless Multimedia • Interworking with the ITU-T H.3XX Series • MEGACO/H.248 as Key Element in Interworking Gateway

4. Features of IMT-2000 • High Speed Data and Video Transmission • Maximum bit rate: 384kbps (outdoor), 2Mbps (Indoor) • Global Mobility • High quality transmission • Appropriate quality for each application can be provided • From 10-3 to 10-6 • Improved Frequency Efficiency • The same frequency band can accommodate a greater number of users • The network platform for the Mobile Multimedia Applications • Video Phone • Video Mail • Video Distribution (streaming / download)

5. Bearers of IMT-2000 and the Type of Services Type of Bearers Bearers Services to be Covered • Audio/Video Application over Circuit Switched Bearer • Based on 3GPP 3G-324M • Various applications with 3G-324M • Video phone • Video mail / Video answering • Audio/Visual content distribution • Interworking between 3G-324M and other networks • Important to launch mobile multimedia successfully Circuit Switched Voice Communication Voice Non-specified Digital Internet Audio／Video Communication Video phone (3GPP 3G-324M) Packet Switched Packet Internet

6. Interworking Between Multimedia Terminals • Interworking with Multimedia terminal on the Internet • Interworking with Multimedia terminal on the PS mobile network • 3G-324M – H.323/SIP Interworking SS7 Packet Switched Mobile Network MGC Circuit Switched Mobile NW H.248 MT (PS) (SIP/H.323) 3G-324M MG Internet H.323/SIP

7. 3GPP 3G-324M Overview • ITU-T developed H.324 Mobile extension (H.324M) • H.324 Annex C has been established in ’98.2 • Improved error robustness • Error robust multiplexing (H.223 Annex A ~ C) • Efficient transport of H.245 control messages • 3GPP extended H.324 Annex C • 3G-324M has been established in ’99.12 • Specified the audio/video CODECs suitable for Wireless Network • Mandatory support of AMR speech CODEC • Mandatory support of H.263 baseline • Optionally but recommended support of MPEG-4 Simple Profile @ Level 0 • Specified the multiplexing for Wireless Network • Mandatory support of H.223 Level 2 (Annex B) • Added several clarifications • Based on the interoperability test carried out by the interested companies • Described in 3G-324M Implementor’s Guide

8. Building Blocks of 3G-324M/ H.324M • H.223 multiplexed bitstream is mapped onto digital channel • Bearer control messages are delivered as in-band data • Modem/Mode negotiation is not applied Out-band Call Control In-band Bearer Control H.245 Wireless Network Wireless Network I/F Audio CODEC AMR H.223 Annex B Video CODEC H.263/MPEG-4

9. Interworking With H.323 • Interworking with H.323 system requires: • Mapping of Call Control Signaling • Mapping of Bearer Control Signaling (I.e. H.245) • Conversion of Media Transport Format • Media Transcoding 3G-324M H.323 Call Control Q.931/H.225.0 TCP Bearer Control H.245 Bearer Control H.245 Wireless Network I/F IP Audio CODEC AMR Audio CODEC H.223 Annex B RTP/UDP Video CODEC H.263/MPEG-4 Video CODEC

10. Interworking with SIP • Interworking with SIP requires: • Mapping of Call Control /Bearer Control Signaling to SIP/SDP • Conversion of Media Transport Format • Media Transcoding 3G-324M SIP Call Control SIP/SDP TCP or UDP Bearer Control H.245 Wireless Network I/F IP Audio CODEC AMR Audio CODEC H.223 Annex B RTP/UDP Video CODEC H.263/MPEG-4 Video CODEC

11. Interworking & Gateway Decomposition • Requirements for gateway • Decomposed GW shall be able to achieve the same interworking functionalities as Monolithic GW • Able to communicate with any 3G-324M/ H.324M compliant terminal • Easy to achieve compatibility between MG and MGC from different vendors • Less interactions between MG and MGC are better • For compatibility between MG and MGC • For reduction of signaling traffic (to accommodate tens of millions of customers)

12. Gateway Configuration • Proposed configuration • H.248/ MEGACO protocol for MGC to MG control • MGC for call control/ signaling • MG for media stream processing • MG or MGC for media stream control (H.245) varying with application • Advantages • Distributed architecture • Scalability • Synergy with converged voice/data network architectures • H.248/ MEGACO advantages for multimedia • Support for multiple terminations in a call context • Media descriptors for voice & video signals • Packages provide flexibility for extensions & customization • ITU-T SG 16 to standardize packages for H.324M support

13. Configuration of 3G-324M – H.323 Gateway • Add/Delete H.245 termination • Rough Resource Control • (max. no of audio/video termination) Bearer Control (H.245) in MG MGC Call Control H.225.0 * Resource Control • Control Audio/Video streams • Based on H.245 signaling • Follow the limitations set by MGC H.248 MG H.245 H.245 NT * H.323 IP 3G-324M wireless TDM H.223 LC Audio NT * LC Video NT * LC:Logical Channel NT:Network Termination

14. Other Configuration Bearer Control (H.245) in MGC MGC Call Control H.225.0 * H.245 * H.245 Resource Control Backhaul of H.245 H.248 MG H.245 H.323 IP 3G-324M wireless TDM H.223 LC Audio NT * LC Video NT * LC:Logical Channel NT:Network Termination

15. Complementary Standards • Complementary standards from different organizations enable: • Wireless multimedia telephony • Interworking between wireless multimedia and ITU-T H.3XX series • ITU-T Standards • Circuit switched standards such as H.324M • Packet switched standards such as H.323 • Interworking standards such as H.246 • Joint IETF & ITU-T • Media gateway control with MEGACO/ H.248 • IETF Standards • IP/ packet standards such as SDP, RTP, & TCP • 3GPP Standards • Wireless standards such as 3G-324M & GSM-AMR speech • ISO/ MPEG Standards • Multimedia standards such as MPEG-4 video

16. Summary • Emerging wireless multimedia applications • Based on 3G-324M/ H.324M • Supported as 3GPP circuit switched service • Interworking to other networks • Scenarios for H.3XX series terminals • Scenarios for other terminals, such as SIP terminals • Gateways to support interworking • Flexible architecture with MGC & MG elements • H.248/ MEGACO protocol for MGC to MG control • Complementary standards help support interworking scenarios

17. Multimedia Gateways • Back up slides and additional information

18. H.324M Transport Via IP Tunneling • 3G-324M audiovisual call via IP-based core network • Save the resource of MG and core network by multiplexing audio and video stream into one connection • Enable precise audio and video synchronization between GWs Bearer Independent Call Control MGC MGC IP-based Core NW H.248 H.248 Circuit Switched Radio Access NW Circuit Switched Radio Access NW MG MG IP tunneling of 3G-324M stream 3G-324M 3G-324M

19. Configuration of tunneling gateway • Gateway for tunneling MGC MGC * Resource Control H.248 MG MG NT 3G-324M 3G-324M TDM H.223 * LC:Logical Channel NT:Network