Robust Loop-Free On-Demand Routing in Ad Hoc Networks

摘要

In this thesis, we explore new techniques for robust, efficient, loop-free on-demand routing in Mobile Ad hoc Networks (MANETs) using the same information (i.e., topology information, sequence numbers, etc.,) used in prior on-demand routing protocol proposals. We provide new insights into the robustness of protocols based on destination-sequence numbers when operating with node failures and loss of routing information, and present a new destination-sequence number framework that works correctly even with failure conditions. We also show how destination-sequence numbers can be manipulated as routing labels for improving performance, rather than being strictly treated as time-stamps. We present two different routing approaches that exploit the topology information that can be collected on-demand during the route request ood search. The first approach translates topology information into labels that are then stored at nodes in strict lexicographic ordering along any successor path to a destination. Loop-freedom is maintained by allowing nodes to only pick 'smaller' labels. The second approach maintains a list of topology information that should not be trusted in-addition to the known path to a destination. Using the notion of trusted topology, nodes can always make routingWe conclude our research with a new on-demand routing technique that exploits the route request search process, which is an integral part of any on- demand routing protocol. Without requiring any additional mechanisms or information, we use the uniqueness of route requests to realize a on-demand routing framework. We, then, present extensions to the basic framework to improve performance using more information that can be collected during the flood search process.