Opportunistic Routing In Multi-hop Wireless Networks

Multihop wireless networks, such as mobile ad hoc networks (MANETs), wireless sensor networks (WSNs), and wireless mesh networks (WMNs), have broad application prospects in monitoring, communication, control, etc. Routing in multi-hop wireless networks presents a great challenge mainly due to the following facts:the mobility of network node, the instability of network link, and the unreliability of wireless transmission. The traditional routing strategy must look for an effective transmission path, and then transfer data. Because of the network of mobile nodes, environmental impacts, the node own failures, and so on, the life span of transmission path is very short, and they seriously reduce the transmission efficiency. On the contrary, opportunistic routing (OR) is not need to find a complete transmission path. Data packets are closer the destination node by each hop transmission through, and the broadcast nature of wireless transmission to improve the success rate of transmission in each hop transmission through. Opportunistic routing effectively improve the transmission route stability, is very suitable for multihop packet loss wireless networks. In this paper, the main research work about Opportunistic routing is carried out as follows:Firstly, this paper proposes an approach which uses cumulative trust to measure intermittent failure (SCMCT) in MANET. In the one-time monitoring, the information entropy is used for taking down the intermittent of nodes response, and a new distributed monitoring scheme with several collaborative detection methods based on pseudo-space distance is defined in this paper. The simulation result shows this approach is much better than the old. In order to improve on the veracity of detection when nodes with high mobility, by the series of subsection monitoring, the monitoring results are seen as classifiers, and the intermittent failure is measured by the cumulative trust. The simulation result shows this approach is wonderful when nodes with high mobility.Secondly, we first present a new routing strategy that generalizes opportunistic routing in multi-channel multi-hop wireless networks. Firstly, after analyzing the seriousness of channel interference and the complexity of channel assignment in Multi-hop Wireless Networks, the novel heuristic channel assignment approach based on the load of network nodes is proposed, which greatly reduces the channel interference of networks. Secondly, we analyze the effective bandwidth of link, in considering the channel Interference, propose the strategy for selecting forwarding candidates set based on EOTT, and prove that EOTT meets the optimization principle.Thirdly, Considering the factors of both advantage path and load balance, this paper takes advantage of back-pressure scheduling in the high-load network and makes use of characteristics of Qos in opportunistic routing transmission, and proposes an opportunistic routing strategy(BPS-OR), which based on back-pressure scheduling. In this strategy, EODB is used to describe the expected differential backlog between current node and the next. In opportunistic routing, EODT is designed to depict the expected delay of transmitting the packet to the destination and it is proved that EODT meets the optimization principle, and then the algorithm of forming forwarding candidates set is given out. Experimental results also show that BPS-OR's throughput is 28% higher than DiffQ in low-load network, and the gains rise to 52% in high-load network, which potentially improves the stabilization of transmission efficiency of the wireless networks.