Due to the recent development of digital TV broadcasting systems, contents data broadcasting using voices or movies has attracted great attention. In general broadcasting systems, the server broadcasts the same data repetitively and clients wait until the first portion of the data is broadcast. Although the server can deliver the data to many clients concurrently, clients have to wait until their desired data are broadcast. We have proposed several methods to reduce waiting time for contents data broadcasting that clients play without interruption. However, we do not consider the packet loss that occurs in actual environments. In actual environments, we need to make the broadcast schedule considering the error resilience. In this paper, we propose a scheduling scheme to reduce the rate of packet loss considering the error resilience. Our proposed scheme can make the broadcast schedule using several replicated frames. In addition, by scheduling many replications of main frame, the error resilience is improved compared to the conventional scheme.

A Scheduling Scheme for Improving Error Resilience on Media Data Broadcasting

Wireless IP-based video broadcast suffers from heavy packet losses caused by multipath fading and interference variations in the wireless channels. This paper addresses this issue by proposing an application-layer error-resilience scheme, called the replicate multiple descriptor coding scheme (RMD). In principle, RMD extends the conventional multiple descriptor transmission strategy with two new features, the selective-frame-based replication and a time-shifted descriptor transmission. We show that with these two features, we are able to exploit the time diversity in a time-sharing channel to mitigate the damage impact and provide more efficient protection for the video. The simulation results confirm that when the packet loss rate is heavy (e.g., 15%–35%), RMD outperforms other schemes in terms of PSNR improved, while only requiring moderate data overheads.

Che-Min Chen

Papers

Application-layer error resilience for wireless IP-based video broadcasting