Routing and Channel Assignment in Multi-Channel Multi-Hop Wireless Networks with Single Network Interface

In this paper, we present a routing and channel assignment protocol for multi-channel multi-hop wireless networks. We view a multi-hop network as an extension to infrastructure networks, where a mobile host may connect to an access point using multi-hop wireless routes, via other mobile hosts or wireless routers. The access points are configured to operate on one of multiple available channels. Mobile hosts and wireless routers can select its operating channel dynamically through channel switching. In this environment, we propose a routing protocol that finds routes and assigns channels to balance load among channels while maintaining connectivity. The protocol works with nodes equipped with a single network interface, which distinguishes our work with other multi-channel routing protocols that require multiple interfaces per node. Supporting nodes with single network interface is beneficial because having multiple interfaces can be costly for small and cheap devices. The protocol discovers multiple routes to multiple access points, possibly operating on different channels. Based on traffic load information, each node selects the “best” route to an access point, and synchronizes its channel with the access point. With this behavior, the channel load is balanced, removing hot spots and improving channel utilization. The channel assignment assures every node has at least one route to an access point, where all intermediate nodes are operating on the same channel. Our simulation results show that the proposed protocol successfully adapts to changing traffic conditions and improves performance over a single-channel protocol and a protocol with random channel assignment.