Exploiting Context Information for V2X Dissemination in Vehicular Networks

Cooperative ITS systems are expected to highly improve the efficiency of road mobility. Wireless communications are used by these systems to disseminate centralized real-time traffic information to radio-equipped vehicles. Current proposals for traffic information dissemination either exploit dedicated cellular transmissions to interested vehicles, or cooperatively relay the information through vehicular ad-hoc networks. However, dedicated cellular transmissions may pose energy cost and traffic scalability issues to network operators. On the contrary, purely ad-hoc solutions may suffer from network disconnections and not always ensure adequate service reliability. To overcome these limitations, this paper introduces RoAHD, a hybrid approach in which a few messages injected through the cellular system are followed by a cooperative multi-hop dissemination in the vehicular network. RoAHD exploits multi-hop road connectivity information obtained at a low channel cost. Thanks to this knowledge, it is capable to operate smart injection decisions to ensure good levels of message delivery.