Fault-Tolerant Routing Method For Mobile Ad Hoc Networks

Mobile ad hoc network is a core part of the mobile communication technique. And it has obvious technology predominance and wide application. But compare with wired network, the probability of failed transmission in mobile ad hoc networks increases greatly. This brings great challenges forward its dependability. Hence, the research of the routing fault-tolerant technique in the environment of mobile ad hoc networks has the theoretic and practical value.The traditional fault-tolerant technique for the node fault in the networks is whether rerouting to build a new routing to retransmit the data that have been sent but haven't been received yet, or retransmitting the data that have been sent but haven't been received yet using other paths. They are not designed for the mobile ah hoc networks, and cannot adapt to the dynamic changes in it.According to the link interruption and the routing failure caused by the node fault, the network coding based fault-tolerant routing method for mobile ad hoc networks can take full advantage of the characteristic of broadcast of the channels to realize the efficient fault-tolerant routing. Because of the characteristic of broadcast of the channels, the packets sent by the node in the networks can be received by all of its neighbour nodes. Then there are many potential forwarders to form multiple paths. Even one of the paths faults caused by the node failure, the data can still be transmitted by other paths without affections. Network coding can not only get the advantages of the max flow of the network multicast, saving the network bandwidth and balancing the link load by allowing the nodes to encode, but also improve the robustness and the adaptability of the network linking.The method also includes the auto-detection of the node failure, the routing policy adjustment and the restoration of the best path. The auto-detection of the node failure can identify and locate the node failure events in the networks, and inform the sink. The routing policy adjustment is used to adjust the routing policy according to the affection of the transmission paths caused by the node failure. It includes the adjustments of the source's transmission rate and the forwarding rates of the middle nodes. The restoration of the best path is used to maintain the best path of the networks and transmit the control messages without encoding. The corresponding simulation results show that the performance of the network coding based fault-tolerant routing method for mobile ad hoc networks is more preferable than the common fault-tolerant techniques.