An Application-aware Delayed-ACK for Video Streaming over IEEE 802.15.3 WPANs

The Dly-ACK scheme is adopted in IEEE 802.15.3 high-rate WPANs to reduce the overhead of the ACK. Although Dly-ACK improves channel utilization, it also causes additional packet delays if not properly used, which is not good for delay sensitive video-dominating scenarios. In this paper, we first investigate the problems of applying Imm-ACK and fixed burst size Dly-ACK schemes for video streaming over IEEE 802.15.3 WPANs. It is shown that the performance of Imm-ACK degrades first and more quickly as the workload increases due to ACK overhead when the channel is good. N-Dly-ACK works quite well in favorable channel conditions, but it almost can not work when the channel quality is poor. Upon the analysis above, We propose an application-aware Dly-ACK algorithm for video streaming over 802.15.3 WPANs, which includes a frame based dynamic Dly-ACK burst size adjusting algorithm and a min-seq sending up algorithm. In order to evaluate the potential of our mechanism, extensive simulations are carried out. The results show that the proposed algorithm outperforms both Imm-ACK and fixed burst size Dly-ACK consistently over all simulated load levels and channel conditions in terms of fraction of decodable video frames