Congestion Aware Routing in Hybrid Wireless Mesh Networks

Multi-radio Wireless Mesh Networks (WMN) are gaining lot of popularity owing to their increased application to community and public safety networks. WMNs form a static wireless backhaul to provide connectivity to mobile clients. The wireless medium, being shared and contended for, creates a number of hurdles including congestion, interference and noise. Multi-radio nodes can take advantage of the wider frequency spectrum. However, current mesh technologies employ a simplistic approach by assigning one channel for client servicing and another for the backhaul network. The improper reuse of the same channel across multiple hops causes extensive co-channel interference leading to lower bandwidth. The problem is aggravated in a hybrid WMN where the mobile clients act as routers for other clients. In this paper, we propose a congestion aware routing protocol, which can successfully establish channel diverse routes through least congested areas of a hybrid WMN. The prime advantage of the protocol is its ability to discover optimal routes in a distributed manner without the requirement of an omniscient network entity. Simulation results show that the congestion aware routing protocol can successfully achieve a high packet delivery ratio with lower routing overhead and latency in a hybrid WMN.