Background and justification

ITU-T Study Group 16 has focused on the H.300-series standardization of tele-time audiovisual conversational services and systems, such as videoconferencing and video telephony, over various types of networks. In past work, either a high level of QoS was assumed to be provided by the network (H.320/ISDN) or the network was assumed to have no ability to provide QoS (H.323 V1/LANs). Looking forward, MM will be most frequently operated over packet networks that support various types of QoS features, including but not limited to ATM QoS services and IP QoS services. The general topic of how MM systems and coders interact with and request QoS from the network and how this relates to end-to-end performance requires further study.

Study Items

• QoS needs of MM systems and coders.
• Preferred signalling methods for QoS in MM systems.
• Study of methods to provide better QoS in lossy networks, including routed packet networks and mobile networks.
• Common API or interfaces to different QoS signalling methods.
• End-to-end latency and QoS.
• Other aspects of end-to-end performance as perceived by the user.
• Alignment with goals related to Mediacom 2004, IP, GII.

Specific task objectives with expected time-frame of completion

• Enhanced QoS signalling in H.323/H.225.0 V4.
• QoS signalling in possible future terminals (2002+).
• Input to terms of reference for audio and video coders that maximize QoS in lossy networks (2000).
• Input to ATM Forum, IETF, IMT-2000, and SG 11 on MM QoS needs (2000).

Relationships

• All project Questions in SG 16.
• IETF for Internet QoS RFCs.
• ATM Forum and SG 11 for ATM QoS.
• SG 16 on Mediacom 2004 project.
• SG 13 on IP and GII projects.
• SG 12 on performance.
• ETSI TIPHON.