Multi-rate combination of opportunistic routing and network coding: An optimization perspective

Recently, wireless communication methods that exploit the broadcast nature of the wireless medium have been attracting growing attention. Among these methods, opportunistic routing and network coding are regarded as the most promising techniques. While there have been some attempts to combine opportunistic routing with network coding to capture the advantages of both techniques, none of these attempts has considered bit-rate selection for data transmission in multi-rate wireless networks. In this paper, we study the potential benefits of the combination of opportunistic routing and network coding with the bit-rate selection mechanism from an optimization perspective. We develop a theoretical model and algorithm for finding the optimal forwarding scheme for a multi-rate combination of opportunistic routing and network coding in a given network. MIT Roofnet trace-based simulations show that considering bit-rate selection in combination with opportunistic routing and network coding has substantial benefits in terms of the expected transmission time compared to multi-rate opportunistic routing, multi-rate network coding, and a fixed-rate combination approach.