A group synchronization mechanism for live media in multicast communications

To support multicast communications for live media, the authors propose a group synchronization mechanism and enhance an intra-stream/inter-stream synchronization mechanism which they previously proposed for live media. The proposed method employs estimates of network delays for adjustment of the output timing among the destinations. The authors have implemented the mechanisms on a lip-synch experimental system. Live video of a speaker and his voice captured at a source are multicast, and then they are synchronized and output at the destinations. This paper also presents the system performance such as coefficient of variation of output interval, total pause time, mean square error of synchronization, average output rate, and average delay.