End-to-end delay reduction technique for videoconferencing over wireless campus networks

Videoconferencing not only needs intra-stream synchronization to ensure the reconstruction quality of the stream, but also has real time requirement to satisfy the natural interaction between participants. This paper analyzed the components of end-to-end delay in the videoconferencing over wireless campus network with the objective of understanding how to reduce the delay as much as possible. Then a Network Resynchronization Delay Reduction (NRDR) algorithm was proposed to determine the optimal queuing deadline for frames in the network resynchronization, which dominates the end-to-end delay. The NRDR synthetically considers three performance metrics: the queuing delay, the discard probability of frames due to deadline misses, and the variation of discarded frames, in the attempt to obtain a compromise between the end-to-end delay and the intrastream synchronization quality. In the experiment, it was demonstrated that the NRDR is capable of providing the optimal synthesis performance, according to different requirements of videoconferencing participants.