Geographical opportunistic routing in dynamic multi-hop cognitive radio networks

In this paper, we discuss the issue of unicast routing in dynamic CR networks. The problem of our concern is: given a set of CR nodes with geographical positions and temporarily available channels, how to design a protocol so that the average number of transmissions per packet for a unicast transmission is minimized. We propose a novel distributed protocol where packets are transmitted through successively geographic closer intermediate destination nodes, until eventually destination is reached. The intermediate destination nodes are within a two-hop neighborhood and locally chosen by a heuristic algorithm we develop. A priority-based opportunistic routing method is adopted to forward the packets between two nearby intermediate destination nodes. Extensive simulations are conducted to show the performance of our protocol.