Kinetic mobility management applied to vehicular ad hoc network protocols

Vehicular Ad Hoc Networks (VANETs) are a particular category of mobile ad hoc networks (MANETs) characterized by a high mobility and a reduced connectivity. In order to develop protocols for vehicular networks, the community may either create VANET specific approaches, or adapt already existing protocols to VANET. While the former may provide efficient specialized solutions, the latter offers an increased interoperability and universality, which is a key issue for industrial partners involved in the deployment of VANET and Intelligent Transportation Systems (ITS). An important aspect in the porting of ad hoc networks solutions to VANET and ITS is an efficient management of vehicular mobility. Mobility Management is a principle aimed at updating network routes or structures in order to keep them coherent with mobile topologies. Mobility management may be proactive or reactive, depending if the updates are triggered with or without topology changes, or if and only if a change in the topology effectively requires to update the structure. Failure to develop efficient mobility management heuristics leads to a waste of network resources and suboptimal routes or structures. The optimal solution is obviously the reactive mobility management, as updates are optimally triggered only when necessary. However, due to its complexity, the reactive mobility management has not attracted as much attention as its proactive counterpart. In this paper, we introduce a location-aware framework, called Kinetic Graphs, that may be followed by ad hoc protocols in order to implement a reactive mobility management. The Kinetic Graph framework is able to capture the dynamics of mobile structures, and is composed of four steps: (i) a representation of the trajectories, (ii) a common message format for the posting of these trajectories, (iii) a time varying weight for building the kinetic structures, (iv) an aperiodic neighborhood maintenance. We eventually provide a example of a successful application of this framework to broadcasting and routing in VANET. (C) 2008 Elsevier B.V. All rights reserved.