A Link Reliability-Aware Route Maintenance Mechanism for Mobile Ad Hoc Networks

Hosts in mobile ad hoc networks (MANET) are capable of self-configuration and they can migrate at will, which makes the network topology highly dynamic. Thus, routes may break easily since the data session fails when one node moves out of the sensing range of its partner. Besides that, if overused, nodes tend to drain their power completely due to the limited battery life. That will result in a short life span of the network, which means serious performance degradation. The routing maintenance in traditional routing protocols such as dynamic source routing (DSR) is triggered only after an active routing path breaks and in most cases, is realized by a route discovery process to build a new route. This kind of "after-the-event" routing maintenance raises the overhead heavily since considerable cost has to be spent in detecting the path break and establishing a new one. In this paper, we propose a new routing maintenance mechanism named link reliability-aware route maintenance (LRRM). Implemented on DSR, our mechanism tries to evaluate the link reliability of each hop actively and replace those debilitated nodes with robust ones through a local recovery if necessary. After that, the route change shall be informed to the source node by unicasting. Simulation results have proven LRRM's validity in extending network lifetime. Our mechanism also outperforms original DSR in throughput, delivery ratio and average end-to-end latency.