CARAVAN: A Communications Architecture for Reliable Adaptive Vehicular Adhoc Networks

Current link layer protocols for safety-related inter-vehicle communication networks suffer from significant scalability and security challenges. Carrier Sense Multiple Access (CSMA) approaches may produce excessive transmission collisions at high vehicle densities and are vulnerable to a variety of Denial of Service (DoS) attacks. Explicit time slot allocation approaches tend to be limited by either the need for a fixed infrastructure, a high number of control messages, or poor bandwidth utilization, particularly in low-density traffic. This paper will present a Communications Architecture for Adaptive Reliable Adhoc Networks (CARAVAN). CARAVAN includes novel adaptations of explicit timeslot allocation protocols for IVC networks. The protocol requires no control messages, provides protection against a range of DoS attacks, significantly improves bandwidth utilization, automatically adjusts the timeslot allocation in response to changes in vehicle speed, and provides for much faster multi-hop message propagation.