Reliable broadcast streaming over 802.11 WLANs with minimum channel usage

In this paper we investigate the interaction of channel code and modulation (i.e., the bitrate) of wireless transmissions and application layer forward error correction in the context of media streaming. To this end, we design a multimedia delivery protocol based on systematic network coding with partial feedback for reliable broadcast streaming over WLANs. Differently from other work, our approach takes into account the trade-off between (i) exploiting feedback-based encoded retransmissions at the multimedia broadcast source to compensate for the lack of MAC-layer error recovery mechanisms, and (ii) the efficient use of the wireless channel resources as given by the selected modulation scheme and the amount of feedback messages. The proposed protocol is tailored to the delay/packet loss rate demands of multimedia traffic and uses a combination of modulation rate and a forward error correction overhead which jointly leads to a minimal channel usage.