Cross-Layer Design of Wireless Mesh Networks with Network Coding

We investigate the optimal design of a multihop wireless mesh network equipped with multiple orthogonal wireless channels and multiple radios. Specifically, we focus on solutions that can efficiently utilize the limited resource to support multiple unicast applications by routing and network coding. We propose a cross-layer optimization framework where the broadcasting feature of the wireless environment, which plays an important role in realizing the achievable gain of network coding, is taken into account. Moreover, we propose a network code construction scheme based on linear programming, with which the possible achievable Coding+MAC gain could be significantly increased. Delay constraints are also included in the network code construction formulation so that the possible impact of the extra decoding delay to the TCP/IP performance can be reduced without changing the upper-layer protocols. The proposed network design based on cross-layer optimization results in significant increase in network throughput.