Joint Scheduling and Wireless Network Coding

In this paper, we establish a new framework for network coding in ad hoc wireless networks. First, we consider a simple wireless network topology to illustrate how network coding can improve throughput and energy efficiency objectives beyond routing solutions. Then, we extend the network coding problem to general wireless networks in conjunction with scheduling-based medium access control (MAC). For that purpose, we partition the nodes into disjoint sets of transmitters and receivers that result in conflict-free network realizations with minimum cost (e.g. power) assignments. We separately activate distinct network realizations using a time division mechanism. Then, we specify the content of network flows through network coding and derive transmission schedules to optimize the throughput or energy measures. Next, we present a method of constructing time-varying linear network codes that satisfy the wireless network properties. Also, we verify via numerical results the superior performance of network coding over routing in terms of throughput and energy efficiency.