Data Dissemination in Vehicular Environments

In the last few decades, Intelligent Transportation Systems (ITS) have been deployed to reduce congestion, enhance mobility, and help save lives. Among the various technologies incorporated is vehicular communication which consists in equipping vehicles with inexpensive wireless devices to enable a decentralized network composed by vehicles and infrastructure points. Such a vehicular network allows vehicles to extend their horizon of awareness to events that are beyond those that on-board sensors alone are able to detect. In this context, one crucial task is the dissemination of data generated by a wide range of applications. On the one hand, safety applications are mostly related to hazardous situations. Therefore, they require a low dissemination delay and reliable delivery to all vehicles in the surroundings. On the other hand, non-safety applications, related to transport efficiency and infotainment, tolerate higher levels of delay, however, they also generate larger data volumes. Due to the limited channel capacity, the data must be selected prior to broadcasting according to the current level of interest of neighboring vehicles. This can be defined based on the current context such as the vehicles’ direction and the age of the data being disseminated. In both categories, applications share the challenges raised by unique characteristics of vehicular networks such as the continual variation in density and predominant intermittent connectivity between vehicles. This thesis focuses on the development of data disseminating solutions that address these challenges while fulfilling the requirements of both safety and non-safety applications