Cross-Layer and Reliable Opportunistic Routing Algorithm for Mobile Ad Hoc Networks

For improving the efficiency and the reliability of the opportunistic routing algorithm, we propose a cross-layer and reliable opportunistic routing algorithm (CBRT) for mobile ad hoc networks, in which the fuzzy logic and topology control are introduced into the opportunistic routing algorithm. In CBRT, the inputs of the fuzzy logic system are the relative variances (rv) of the metrics rather than the metrics'values; by this, the number of fuzzy rules is reduced dramatically. Moreover, the number of fuzzy rules does not increase when the number of inputs increases. For improving routing reliability and reducing the control cost, in CBRT, the relay node degree is a range rather than a constant number. The nodes are divided into different categories based on their relay node degree. The nodes adjust their transmission power based on which categories that they belong to. In addition, for investigating the effect of the node mobility on routing performance, we propose a link lifetime prediction algorithm which takes the moving speed and moving direction into account. In CBRT, the source node determines the relaying priorities of the candidate relay nodes based on their utilities. The relay node whose utility is large has high priority to forward the data packet to next hop. By these innovations, the performance of CBRT is much better than that of ExOR; however, the computation complexity does not increase in CBRT.