Vehicle-to-Roadside Multihop Data Delivery in 802.11p/WAVE Vehicular Ad Hoc Networks

A wide variety of applications aimed to improve road safety and traffic efficiency or to provide comfort/entertainment to passengers in vehicles are intended to be delivered in VANETs (Vehicular Ad hoc Networks) in the near future. Most of these applications require vehicles to access a remote network. However, due to the high costs needed for deploying and maintaining an ubiquitous roadside infrastructure, just a few stationary access points are expected to be installed, which provide partial network coverage; hence multihop communications must be enforced in order to provide remote connectivity to vehicles on the road. The upcoming IEEE 802.11p/WAVE (Wireless Access for Vehicular Environment) standard relies on a multi-channel architecture to deliver both safety and non-safety applications to vehicles, but it does not explicitly support multihop data delivery. In this paper some main design issues are investigated which deal with the provision of multihop communications in 802.11p/WAVE networks. A set of forwarding schemes compliant to the draft standard is specified and analyzed, which aim to improve data delivery and delay performances, by reducing the overhead incurred for relaying packets.