Network Coding-Aware Queue Management for Unicast Flows over Coded Wireless Networks

We are interested in unicast flows over wireless networks with intersession network coding (such as COPE [1]). TCP flows over coded wireless networks do not fully exploit network coding opportunities due to their bursty behavior and to the fact that TCP is agnostic to the underlying network coding. In this paper, we take the following steps. First, we formulate congestion control for unicast flows over coded wireless networks as a network utility maximization problem and we present a distributed solution. Second, by mimicking the structure of the optimal solution, we propose a "network-coding aware" queue management scheme (NCAQM) at intermediate nodes. We make no changes to TCP or MAC protocols. We demonstrate, via simulation, that TCP over NCAQM performs significantly better than TCP over COPE.