Research On Opportunistic Routing Protocol In Ad Hoc Network Based On OPNET

Ad Hoc networks are becoming a new attractive communication paradigm. Routing protocol design is critical to the performance and reliability of wireless Ad Hoc networks. These traditional routing protocols choose the best sequence of nodes between the source and destination, and forward each packet through that sequence. They are ineffective when coping with unreliable and unpredictable wireless medium.To improve the network performance, an idea of opportunistic routing which works by broadcasting and uses of many links to forward the packets is become a research direction gradually.Opportunistic routing protocol uses of many links to forward the packets, so the wireless link is strengthened, especially in unreliable and unpredictable wireless medium, the network performance is inhanced obviously.Compare with the traditional routing protocols, opportunistic routing protocols have two advantages. First, opportunistic routing protocols can combine many unreliable and unpredictable wireless link to a strong link. Second, opportunistic routing protocols can use the link which has high loss rate but long transmission distance.In this paper, we first introduce the idea of opportunistic routing and the classic opportunistic routing ExOR, and then we develop a Multi-stream Opportunistic Routing protocol (MSOR). MSOR broadcasts every packet and each packet would be forwarded only once by nodes which received the packet in the forwarder list before. Through more nodes forward each packet, the wireless link is strengthened. In addition, MSOR takes advantage of multiple long but radio lossy links concurrently, resulting in high expected progress per transmission, so the packet delay would decrease remarkably. Through simulation on OPNET, our preliminary results show that MSOR is of high efficiency and can effectively support multiple simultaneous flows. Especially in unreliable and unpredictable wireless networks, MSOR has shown better performance than traditional routing protocols such as AODV.