A Study of Long Distance Traffic Using the AODV Protocol in a Vehicular Ad Hoc Network

In vehicular ad hoc networks (VANETs) vehicles communicate with each other without any fixed infrastructure (inter-vehicular communication). VANETs have received wide attention in the research community in recent years. Wireless routing protocols (e.g. DSR or AODV) were studied in freeway scenarios. But whereas recent research dealt with different vehicle density rates (number of vehicles per km) the distance and especially the long distance between the source and the destination vehicles has not been tackled well in the published literature. We studied the performance of the AODV protocol considering different distances between the source and destination vehicles. The mobility traces were generated by a microscopic vehicular traffic generator based on the intelligent-driver model. We addressed the limitations of other protocols in this scenario by implementing some improvements to increase the packet delivery rate and the throughput, and to decrease the normalized routing load. For these improvements we used mobility prediction based on neighborhood knowledge to guarantee more reliable intermediate nodes and therefore a more stable route to the destination. The reliability of the intermediate nodes gets more and more important the longer the routes are, as we show in this paper.