Rate Control With Pairwise Inter-Session Network Coding

In this paper, the authors develop a distributed rate control algorithm for networks with multiple unicast-sessions when network coding is allowed across different sessions. Building on recent flow-based characterization of pairwise inter-session network coding, the corresponding optimal rate-control problem is formulated as a convex optimization problem. The formulation exploits pairwise coding possibilities between any pair of sessions, where any coded symbol is formed by coding over at most two original symbols. The objective function is the sum of the utilities based on the rates supported by each unicast session. Working on the Lagrangian of the formulated problem, a distributed algorithm is developed with little coordination among intermediate nodes.