Route fragility: a novel metric for route selection in mobile ad hoc networks

A key factor deciding the performance of a muting protocol in mobile ad hoc networks is the manner in which it adapts to mute changes caused by mobility. Exploiting the intuition that a less dynamic mute lasts longer, we propose a new metric, the Route FragiI&v Coeficient (RFC), to compare mutes. RFC estimates the rate at which a given mute expands or contracts. Expansion refers to adjacent nodes moving apart, while contraction refers to their moving closer. RFC combines the individual link contraction or expansion behavior to pmsent a unified picture of the mute dynamics. We demonstrate that lower the value of RFC, more static (less fragile) the mute. We then use this metric as a basis for route selection so that route discovery yields mutes that last longer and hence increase throughput while reducing contml overhead. We pmvide a simple distributed mechanism to compute RFC, so that a Route-Request W Q ) packet contains the metric for the path it travened, when it reaches the destination. The Dynamic Source Routing Protocol (DSR). is enhanced with the proposed metric in the NS-2 simulation environment. Simulation msults am provided to demonstrate improvement in thmugbput and reduction in routing pmtocol overhead with increased mobility.