A reliable and timely medium access control protocol for vehicular ad hoc networks

Many vehicular safety applications can be implemented more easily and practically by using reliable and real-time communications between vehicles and roadside infrastructures. Neither schedule-based nor contention-based conventional MAC protocols can properly satisfy the safety requirements of such applications. In contention-based protocols, packets may experience unbounded delays and schedule-based protocols are sensitive to users' motion. In this paper, a new STDMA MAC protocol which provides both reliable and real-time medium access is introduced. Simulation results show that the proposed protocol has succeeded in providing an acceptable level of reliable and real-time communications, simultaneously.