Control mechanisms for ITS cooperative safety applications

In the last decades, Intelligent Transportation Systems (ITS) have been considered as one of the most emerging research area due to their promising role in promoting traffic efficiency and enhancing road safety. ITS cooperative safety applications, being the most vital and critical, have gained a lot of attention. The effectiveness of these applications depends widely on the efficient exchange of two main types of information.  The periodic awareness corresponding to the one-hop location information of surrounding environment and the multi-hop event-driven information generated at the detection of a safety situation. Due to the large scale characteristic of ITS, this information is expected to be subject to severe congestion which might impact its reliable reception. The goal of this thesis is to focus on the reliable and robust control of safety-related information by reducing the channel congestion and at the same time taking into account the requirements of safety applications. We address first the event-driven safety information. We proposed a multi-hop policy showed to improve the dissemination of the event-driven information. However, it remains strongly sensitive to the channel load resulting from periodic awareness transmissions. On the other hand, the effective transmission of event-driven information depends primarily on the accurate detection of safety events and accordingly on the accuracy of awareness.  Thus, we provide an efficient awareness control mechanism in order to provide better accuracy and limit the channel congestion. The approaches proposed in this thesis have deeply investigated the trade-off between ensuring the requirements of cooperative safety and the efficient management of congestion in vehicular network.