3GPP Work Item description

This page contains informal descriptive text only.  See master WID page for further details.

Feature: 3G-324M Video Telephony Call Setup Times Improvements

Video telephony is very important for the successful adoption of UMTS. 3G-324M, the basis for 3GPP circuit-switched multimedia calls, was based on H.324 and has been evolving ever since its first introduction into 3GPP specifications in Rel-99. As part of this evolution, new codecs have been proposed and adopted in 3GPP to improve the quality of service. These evolutions have been focusing so far on the media quality and not on other aspects such as call set-up time, which also greatly affects user experience.

Using Rel-99, the time taken to set up a 3G-324M call is currently significantly longer than that taken to set up a voice call. This quality of experience is broadly acceptable to early UMTS adopters. However, as adoption becomes broader, this tolerance will decrease.

In the interest of facilitating broader adoption of UMTS and mobile video telephony, further solutions should be identified to accelerate 3G-324M.

The final objective of this work item is to reduce 3G-324M call set-up time to the equivalent of a voice call. Since methods to achieve this goal have already been proposed and adopted in other standards bodies, we propose to start the work by investigating and reusing as much as is relevant of the existing solutions. Therefore we suggest a phased approach to this work. SA4 will liaise to SA1 to get requirements for this work (and will liase also with GERAN depending on the output on the Feasibility Study on Enhanced Support of Video Telephony).   

Phase 1 (Dec 2005): Adopt one of the currently available and stable technologies (e.g. the WNSRP proposal in ITU-T). The likely output of this phase would be a CR.

Phase 2 (Dec 2006): Assess the output of Phase 1 against the defined requirements. In the event of further development being needed, SA4 shall open a selection process for innovative technical proposals. Input from other standards bodies (ITU-T, TISPAN, 3GPP2 etc.) will be invited. Any selected solution shall be backwardly compatible or agnostic to the phase 1 solution.

Service Aspects:

This work item is focused on delivering enhanced user experience of 3G-324M. This may be accomplished by several methods including optimizing the in-band call control (H.245)