Error and Congestion Resilient Video Streaming over Broadband Wireless

In this paper, error resilience is achieved by adaptive, application-layer rateless channel coding, which is used to protect H.264/Advanced Video Coding (AVC) codec data-partitioned videos. A packetization strategy is an effective tool to control error rates and, in the paper, source-coded data partitioning serves to allocate smaller packets to more important compressed video data. The scheme for doing this is applied to real-time streaming across a broadband wireless link. The advantages of rateless code rate adaptivity are then demonstrated in the paper. Because the data partitions of a video slice are each assigned to different network packets, in congestion-prone wireless networks the increased number of packets per slice and their size disparity may increase the packet loss rate from buffer overflows. As a form of congestion resilience, this paper recommends packet-size dependent scheduling as a relatively simple way of alleviating the buffer-overflow problem arising from data-partitioned packets. The paper also contributes an analysis of data partitioning and packet sizes as a prelude to considering scheduling regimes. The combination of adaptive channel coding and prioritized packetization for error resilience with packet-size dependent packet scheduling results in a robust streaming scheme specialized for broadband wireless and real-time streaming applications such as video conferencing, video telephony, and telemedicine

Engineering wireless broadband access to IPTV

IPTV is now extending to wireless broadband access. If broadband video streaming is to achieve competitive quality the video stream itself must be carefully engineered to cope with challenging wireless channel conditions. This paper presents a scheme for doing this for H.264/AVC codec streaming across a WiMAX link. Packetization is an effective tool to govern error rates and, in the paper, source-coded data-partitioning serves to allocate smaller packets to more important data. A packetization strategy is insufficient in itself, as temporal error propagation should also be addressed by insertion of intra-coded data. It may be necessary to include redundant packets when channel conditions worsen. The whole should be protected by application-layer rateless coding. Therefore, the contribution of the paper is a complete scheme comprised of various protection measures aimed at robust IPTV streaming. Due to computational overheads, the scheme is aimed at the new generation of smartphones with GHz CPUs