Capacity Region of a Wireless Mesh Backhaul Network over the CSMA/CA MAC

This paper studies the maximum throughput that can be supported by a given wireless mesh backhaul network, over a practical CSMA/CA medium access control (MAC) protocol. We resort to the multi-commodity flow (MCF) formulation, augmented with the conflict-graph constraints, to jointly compute the maximum throughput and the associated optimal network dimensioning; while use a novel approach to take into account the collision overhead in the distributed CSMA/CA MAC. Such overhead has been ignored by the existing MCF-based capacity studies, which assume impractical centralized scheduling and result in aggressive network dimensioning, unachievable over the CSMA/CA MAC. We develop a generic method to integrate the CSMA/CA MAC analysis with the MCF formulation for optimal network capacity analysis, and derive both an upper bound and a lower bound of the network throughput over a practical CSMA/CA protocol. To the best of our knowledge, this paper is the first rigorous theoretical study of the achievable capacity over a multi-hop CSMA/CA based wireless network.