RPB-MACn: A Relative Position Based Collision-free MAC Nucleus for Vehicular Ad Hoc Networks

Vehicular Ad Hoc Networks (VANETs) will play a vital role in reducing the number of road accidents and fatalities as well as vehicular traffic optimization. Though an instance of Mobile Ad Hoc Networks (MANETs), the highly mobile and dynamic environment of VANET introduces new research challenges. To quickly adapt to the highly mobile and constantly changing topology and still meet the desired application requirements, it is vital for the VANET media access control (MAC) protocol guarantees wireless channel access with minimal delay and minimal exchange of control messages. This paper proposes an innovative Relative-Position-Based MAC Nucleus (RPB-MACn). By combining the dedicated communication channel pair and the dedicated directional antenna associated to the relative position of vehicles, a conceptually contention-free RPB-MACn mechanism for VANET is realized (when coupling with dynamic power control mechanism). Consequently, RPB-MACn can meet all the key requirements of the MAC protocol in a VANET system.