A Conflict Analysis Framework for QoS-Aware Routing in Contention-Based Wireless Mesh Networks with Beamforming Antennas

Utilizing smart beamforming antennas in contention-based wireless mesh networks has proven to provide a significant increase in the network capacity. Nevertheless, their effectiveness in providing additional QoS guarantees is still under-explored. In this paper, we develop a framework for analyzing conflicts on wireless links considering both the physical interference and the operation of the underlying directional MAC protocol. Based on a novel taxonomy, we classify the link conflicts into several categories and propose a novel colored conflict graph abstraction to model the network interference pattern in the presence of contention-based directional MAC protocols. Using the proposed colored conflict graph, we derive a closed form expression for the probability of successful transmission over a wireless link given that all the bandwidth requirements are satisfied. Based on our analysis, we formulate the bandwidth-guaranteed routing problem as an optimization problem. Since the problem is NP-hard, we present a heuristic algorithm for joint routing and admission control to find single-path bandwidth-guaranteed routes. Using extensive simulations, we demonstrate the accuracy of our conflict analysis and the ability of the proposed algorithm to provide QoS guarantees along with efficient channel utilization.