A forwarding protocol with relay acknowledgement for vehicular ad-hoc networks

In vehicular ad-hoc networks (VANETs), mobility is one of key characteristics that have a significant effect on routing performance because it causes dynamic changes of network topology. In this paper, we propose a contention based forwarding protocol that exploits geographic or virtual location information. A node that is closer to the destination node has a higher priority in competing for the wireless channel, and forwards packets as a relay node earlier than other adjacent nodes. When a packet is forwarded by a relay node, its preceding node informs adjacent nodes that it has been already relayed to prevent duplication of packet delivery. Through ns-2 simulations, we show that the proposed scheme can significantly improve the network performance in terms of the packet delivery ratio and the end-to-end delay in various VANET scenarios.