Vehicular Ad Hoc Networks and Trajectory-Based Routing

With the rapid advance in short-range radio communications for (e.g., IEEE 802.11p), vehicular ad hoc networks have emerged as a new paradigm of mobile ad hoc networks. Within a vehicle ad hoc network, there are several types of wireless communications, including vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and infrastructure-to-vehicle (I2V). A wide variety of existing applications are being developed based on vehicular ad hoc networks, such as traffic safety, transport efficiency, and entertainment on the move. A key enabling technology for vehicular ad hoc network is message routing among vehicles. Efficient message routing is particularly challenging for vehicular ad hoc networks because of frequent network disruption, fast topological change and mobility uncertainty. The vehicular trajectory knowledge plays a key role in message routing. By extracting mobility patterns from historical vehicular traces, we develop trajectory predictions by using multiple order Markov chains. We then present routing algorithms taking full advantage of predicted probabilistic vehicular trajectories. We carry out extensive simulations based on large datasets of real GPS vehicular traces. The simulation results demonstrate that the trajectory based routing algorithms can achieve higher delivery ratio at lower cost.