On the average course length in mobility models for mobile ad hoc networks

In simulations of Manets, mobile nodes usually move in a random direction until they reach their target, then stop and start heading to another direction. We propose in this paper to study the average course length of mobile nodes, from the moment they start moving to their respective destinations, and the time they stop. Since the knowledge of the time nodes keep on heading to their targets helps adjusting the refreshing period of ad hoc routing and topology control protocols, it becomes possible to obtain an insight of the expected improvements these protocols can get from the use of aperiodic instead of periodical updates. We show in this paper that when using fair metrics, the length of nodes movements following a Random-Waypoint mobility model (RWM) or a Manhattan mobility model (ManM) is situated around 10 seconds in the worst case scenario. Therefore, by fixing a refreshing period to this
time interval, it becomes possible to improve the global performance of topology control and routing protocols.