Merging network coding with feedback management in multicast streaming

Abstract

Reliable multicast over wireless poses interesting challenges arising from the unreliable nature of the wireless medium. Recovering lost packets is particularly challenging in multicast scenarios since different receivers lose different packets. For this reason, simply retransmitting packets does not scale well with the number of receivers and particularly with the packet loss rate. A more efficient alternative is to use erasure codes to generate packets that can help many receivers at the same time. In this paper, we propose using online network coding to send coded packets that repair losses according to feedback reports sent by the clients. In particular, we propose using a recently developed scheduler for controlling feedback reports, which also allows differentiating the QoS provided to clients, and combine it with an online coding approach to provide novel stochastic guarantees of worst-case delay as required for QoS sensitive applications. We show preliminary simulation results that confirm the bounded decoding delay of our approach in a streaming application.