A Novel Two-Timer-Based Broadcast Routing Algorithm for Vehicular Ad-Hoc Networks

This paper proposes a novel two-timer-based broadcast routing algorithm for Vehicular Ad-hoc Networks (VANETs), including a new relay selection scheme and a priority queue mechanism to deal with two patterns of safety messages. The new relay selection scheme can not only minimize the number of relay nodes but also improve the packet penetration speed. Two timers are utilized to decide whether the node forwards the received packets. The first timer is used to stabilize the receiving process, and before it expires, the node would update the relative distance to the last sender of the packet. When the first timer is due, the second timer would be activated to ensure that only the furthest receiver from the last sender of the packet would forward the packet. Moreover, a priority queue mechanism is introduced to guarantee the fast spread of time-critical safety messages. The proposed algorithm is totally distributed and relies on GPS information, yet any other prior knowledge such as network topology is not required. Simulation results reveal that our proposed algorithm provides higher efficiency compared with the slotted one-persistence algorithm and the traditional flooding based one.