The Impact of Interference on Optimal Multi-path Routing in Ad Hoc Networks

We develop a queueing model characterizing explicitly the impact of interference on end-to-end performance measures such as throughput in ad hoc networks, emphasizing the performance trade-off between single-path and multi-path routing. It may seem attractive to employ multi-path routing, but as all nodes share a single channel, efficiency may drop due to increased interference levels thus yielding single-path performance for some topologies. We formulate a nonlinear programming problem to optimize network performance. Next, we focus on network capacity and show that for this objective the optimum could be found by solving an exponential number of linear programmes. We propose a greedy algorithm that efficiently searches these programmes to approximate the optimal solution. Numerical results for small topologies provide structural insight in optimal path selection and demonstrate the excellent performance of the proposed algorithm. Besides, larger networks and more advanced scenarios with multiple source-destination pairs and different radio ranges are analyzed.