Adaptive feedback techniques for synchronized multimedia retrieval over integrated networks

The authors have developed intermedia synchronization techniques for multimedia on-demand retrieval over integrated networks in the absence of global clocks. In these techniques, multimedia servers use lightweight messages called feedback units transmitted by media display sites (such as audiophones and videophones, generically referred to as mediaphones) to detect asynchronies among those sites. They present strategies by which the multimedia server can adaptively control the feedback transmission rate from that mediaphone, so as to minimize the associated overheads without permitting the asynchrony to exceed tolerable limits. They compare the performance of various resynchronization policies such as conservative, aggressive, and probabilistic. Performance evaluation of the feedback techniques indicates that their overheads are negligible; for a typical audio/video playback environment, the feedback frequency was about one in a hundred