Routing and Channel Assignment in Multi-Channel Multi-Hop Wireless Networks with Single-NIC Devices

In this paper, we present a routing and channel assignment protocol for multi-channel multi-hop wireless networks. We consider a multi-hop network, where a mobile host may connect to an access point using multi-hop wireless routes, via other mobile hosts or wireless routers. Also, we consider a multi-channel network where multiple non-overlapping (orthogonal) channels are available, and each host or router can dynamically select a channel to improve performance. In this environment, we propose a multi-channel routing protocol that works with nodes (mobile hosts or wireless routers) equipped with a single NIC (network interface card). Supporting single NIC devices is beneficial because having multiple network interface can be costly for small and cheap devices. Using the proposed protocol, nodes discover multiple routes to multiple access points possibly operating on different channels. Based on the traffic load information, each node selects the “best” route to an access point, and stays on the channel where the access point is on. With this behavior, the protocol balances load across the channels, thus removing hot spots and improving channel utilization. The channel assignment does not cause network partitions, assuring that if a path exists from a node to an access point, the node finds a route to an access point, where all the intermediate nodes and the destination are operating on the same channel. Our simulation results 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.