Joint Topology Control and Routing in IEEE 802.11-Based Multiradio Multichannel Mesh Networks

Due to low cost, ease of deployment, increased coverage, and enhanced capacity, multiradio mesh networks that utilize inexpensive and readily available Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless interfaces are touted as the new frontier of wireless networking. In a multihop mesh system, the close interaction between topology control and routing selection affects the system throughput of a wireless network. This paper proposes a novel joint topology control and routing (JTCR) protocol for a multiradio multichannel wireless mesh network to exploit both channel diversity and spatial reusability. It resides between medium access control and the network layer and aims to improve the network throughput by coordinating transmission power, channel assignment, and route selection among multiple nodes in a distributed way. JTCR jointly coordinates the transmission power at each node, the channel selection on each wireless interface, and the route selection among interfaces based on the traffic information that is measured and exchanged among two-hop neighbor nodes. An equivalent channel air time metric (ECATM) is presented to quantify the difference of various adjustment candidates. This protocol achieves the efficient utilization of available channels by selecting a feasible adjustment candidate with the smallest EC ATM value and coordinating affected nodes to realize the adjustment. Our NS-2-based simulation results show that the network throughput can be significantly improved by using our proposed solution.