On interference-aware cooperation policies for wireless ad hoc networks

In this paper we devise efficient optimization techniques to find optimal routing and scheduling policies for wireless ad hoc networks in the presence of multi-user interference and cooperative transmissions. Our focus is to assess the impact of interference among distinct data flows on optimal routing paths and related transmission schedules. In our reference scenario, all nodes have a single antenna and can cooperate in the transmission of packets. Given that, we first model the cooperative transmission problem using linear programming (LP). Thus, for an efficient solution, we reformulate the joint routing and scheduling problem as a single-pair shortest path problem, which is solved using the A* search algorithm through specialized heuristics. Simulation results of the obtained optimal policies confirm the importance of avoiding interfering paths and that interference-aware routing can substantially improve the network performance in terms of throughput and energy consumption, even when the number of interfering paths is small. Our models provide useful performance bounds for the design of distributed cooperative transmission protocols in ad hoc networks.