Investigating the Use of Message Reneging in Multi-hop 802.11p VANETs

Vehicular ad hoc networks (VANETs) are becoming an important technology to enable enhanced road safety. Based on the 802.11p standard model, VANETs are known to suffer from channel congestion when the number of vehicles increases. Also, problems of fading and channel loss conditions on the road, make the effective delivery rate in VANETs very low beyond distances that are half of the transmission range. In this paper, we are interested in multi-hop message delivery in VANETs to extend the delivery range of safety messages beyond a one-hop range. We investigate the use of priority to favor on-hop messages over relayed ones according to the distance from the event originator. We also investigate the effect of using a limited delay in messages queues versus message reneging with such a scheme. An analytic and simulation study show interesting results under various constraints.