Butteries in the Mesh: Lightweight Localized Wireless Network Coding

In this paper, BFLY-a lightweight localized network coding protocol for wireless mesh networks-is proposed. To supplement forwarding packets in classical networks, intermediate wireless nodes code packets from different sources, so that each transmission's information content is increased by a factor of more than one. Prior work allowed intermediate nodes to code (i.e, XOR) packets such that the recipient of that coded message must decode the message before forwarding. BFLY, however, allows intermediate recipients to, in addition to XOR-ing, forward coded packets; and thus further exploits network coding opportunities in multihop wireless networks. BFLY utilizes knowledge of the local topologies and source route information in the packet headers. We have developed network coding modules in ns-2 that facilitate simulation with large networks. Simulation studies show that BFLY can increase overall network throughput by a factor of 1.2 - 2 and reduce packet end-to-end latency. Finally, jointly coding with BFLY and COPE always yields more gain than the individual approaches.