Contention-Aware Cooperative Routing in Wireless Mesh Networks

Cooperative communication is a new physical layer technique which improves link capacity by exploiting broadcast nature and spatial diversity of wireless channel. The introduction of cooperative communication in wireless networks changes the traditional definition of link and the contention relationship among links. In this paper, we focus on cooperative communication aware routing protocol design in wireless mesh networks, targeting at maximizing the overall end-to-end throughput of the whole network and meanwhile taking contention relationship among multiple links into consideration. We propose a routing metric called contention-aware cooperative metric (CCM) and prove that CCM has the isotonic property. Therefore, efficient algorithms such as Dijkstra or Bellman-Ford can be used to find CCM-based minimum cost paths. Based on CCM, we propose a routing protocol called Contention-aware Cooperative Routing (CCR) which can be implemented in both link-state and distance-vector routing protocols. Extensive simulations are conducted on ns-2 to evaluate the performance of our novel routing metric and routing protocol. The results show that CCR achieves significant throughput gain compared with hop- count-based routing and ETT-based routing. The end-to-end delay is also dramatically reduced under CCR routing.