Packet-level forward erasure correction with user fairness in lossy wireless networks

Packet-level erasure correction is considered for downstream packets each of which is delivered from a base station to an individual receiver (i.e., user) over a lossy shared wireless network where only a very limited upstream feedback is provided. Note that, while the destination of each packet is a single user, each packet can be overheard by all users in the shared network. With exploiting this overhearing property of wireless links, we focus on packet recovery by exclusive-OR (XOR) packet composition-based forward-erasure-correction (FEC). For network applications with packet-loss tolerance and delay-time limitation, our goal is to increase the effective packet received rate (the ratio of finally received/recovered packets after applying FEC) of each user with fairness in a low-cost manner. We propose a simple XOR packet composition scheme that can approximately maximize the minimum effective packet received rate among users, based on an experimentally suggested linear relation between the packet loss rates and the optimal packet composition ratios among users. Simulation results clearly indicate the potential effectiveness of the proposal.