A Cooperative Congestion Control Approach within VANETs: Formal Verification and Performance Evaluation

The main objective of congestion control is to best exploit the available network resources while preventing sustained overloads of network nodes and links. Appropriate congestion control mechanisms are essential to provide efficient operation of a network. Ensuring congestion control within vehicular ad hoc networks faces special challenges, due to the specificities of such environment ( High mobility of nodes, high rate of topology changes, high variability in nodes density and neighborhood configuration, broadcast/geocast communication nature, etc.). In this context, we present in this paper a cooperative and fully distributed congestion control approach, based on dynamic scheduling and transmission of priority-based messages, to ensure reliable and safe communication architecture within VANET. Messages priorities are dynamically evaluated according to their types, the network context, and the neighboring nodes configuration. Considering the context of high reliability and real-time response required for intervehicular communications ( including emergency breaking notification for example), we propose a complete validation method of our congestion control algorithms, taking into account reliability, temporal, and operational aspects.