Enhanced Hybrid Traffic-Aware Routing Protocol for Vehicular Ad hoc Networks

In this paper, we presents a routing protocol called Enhanced Hybrid Traffic-Aware Routing (EHTAR) to cope with the dynamics of Vehicular Ad Hoc Network (VANET) in urban environment. In EHTAR, an elected functional node called Junc-Tracker located at each junction is used to explore the real-time vehicular and network traffic information in each road segment. This information enables each Junc-Tracker to determine a reliability score for each road segment and assist with the selection of a more robust and efficient routing path during transmissions. The reliability score of each junction is updated periodically to adapt to the dynamics in the environment and recalculate these reliability scores if necessary. In addition, we also adopt an enhanced next forwarder selection scheme to make better decisions on how to select a more efficient and stable next forwarder by using location prediction and link duration estimation to enhance and maximize the performance of EHTAR. Simulation results shows EHTAR not only achieves a higher delivery ratio and transmission throughput, but also out performs other position-based routing protocols that adopt the traditional greedy forwarding strategy.