Congestion aware routing metric for opportunistic routing in wireless ad-hoc networks

Opportunistic Routing is a new routing paradigm in wireless ad-hoc networks. In this paradigm, the packets are routed with no fixed and predetermined next hop in the network. Broadcast nature of wireless medium is used in opportunistic routing and the next hop will be selected of the receivers of a packet. A problem that has still remained in opportunistic routing is congestion occurrence along the shortest paths. This is due to unsuitable next hop selection through the utilized routing metric. Queue length consideration in the routing metric is necessary but not sufficient to avoid network congestion. Therefore, a routing metric is proposed in this paper that considers the transmission rate of the nodes in addition to their backlog queue. Simulation results show that the proposed metric has better performance compared to the metric that only considers the queue length in the next hop selection procedure.