Link Adaptation for Video Transmission over COFDM based WLANs
PL Ferre, Angela Doufexi, James T H Chung How, Andrew Nix, David Bull · Bristol Research (University of Bristol) · 2003
Wireless Local Area Networks (WLANs) such as IEEE 802.11a/g and Hiperlan/2 operate in numerous transmission modes, each providing different throughputs and reliability levels. Link adaptation algorithms proposed in the literature ([1], [2], and [3]) maximise data throughput based on channel conditions and assume that only error-free packets may be passed on to the higher layer. For multimedia applications such as video transmission, completely error-free communication is not essential, especially if robust video compression techniques are applied. In such scenarios, better decoded video quality might be obtained with a video stream transmitted at a higher bit-rate but with some degree of transmission error, rather than an error free video stream at a lower bit-rate. In this paper, we present a link adaptation scheme that improves the Quality of Service (QoS) for video transmission in terms of the overall received video quality, rather than by maximising error-free throughput. Simulation results using the H.263+ video compression standard over IEEE 802.11a are presented.