A Novel Dual Priority Cooperative Opportunistic Routing Scheme in Wireless Multi-Hop Networks

Distributed cooperation among the forwarding candidates is the main challenge of opportunistic routing design for wireless multi-hop networks. Timer-based coordination is an efficient way to solve this problem. However this method leads to unnecessary duplicate transmission problem which will degrade the system performance. In the scenario where nodes are nonadjacent, the duplicate transmission problem gets even worse. To avoid the useless retransmission, this paper proposes a pure network layer scheme called Dual Priority Cooperative Opportunistic Routing Scheme (DPCOR). DPCOR exploits the global network information to complete the network layer confirmation. The nodes with lower global priority receive a duplicate packet will not respond again. Furthermore, it combines the local link quality variation and adjacent information to classify the forwarding candidates into three levels with local priority. As the packets are broadcasted at different time according to the local priority, the scheme can get more time diversity, which can avoid collision and improve performance effectively. We test DPCOR by using the simulation in various network scenarios. The results show that DPCOR achieve significant performance improvement with less transmission cost compared to the traditional routing and typical opportunistic routing.