Optimization of Routing, Network Coding and Scheduling in Wireless Multicast Ad-hoc Networks with Topology Compression

In this paper, we present new methodology and results for joint routing and link scheduling optimization in multicast wireless ad-hoc networks. The impact of multicast diversity on scheduling is controlled by using topology compression concept quantified through compressed multicast topology matrix. To define topology matrix, first a set of all possible multicast paths, including network coded paths, is identified. A subset of these paths with appropriate rates is chosen to maximize achievable throughput or throughput per sum of transmitting powers on the route, in a conflict free environment created by proper scheduling. Therefore this optimization provides two improvement gains, throughput gain from scheduling on a compressed network topology and the gain from mixed path selection optimizations with a careful compromise between the multicast diversity and network coding. Numerical results, as illustration, are presented for a simple wireless butterfly network. If just throughput regardless of power consumption is maximized, then depending on the system parameters both a network coded structure or a plain routing can be optimum. On the other hand if throughput per power is maximized, a mixed set of plain routing paths is the optimum solution.