VIMAC: A Vehicular Information Medium Access Control Protocol for High Reliable and Low Latency Transmissions in VANET

Time division multiple access (TDMA)-based vehicular ad hoc networks (VANETs) can enhance road safety level through providing safety related applications which pose stringent latency and reliable requirements. In this paper, we propose a novel TDMA-based medium access control (MAC) protocol which is able to attain high reliable and low latency transmissions. Our proposed scheme contains two processes, prediction and allocation. The former process, prediction, can be used to mitigate a portion of collisions before their occurrences. There still exists unpredictable collisions due to the vehicular placement. In the case of prediction process being unavailable, the allocation process is able to reduce a portion of the unavoidable collisions with the help of upper layer information. We build a system level simulation platform that merges SUMO and MATLAB to compare the proposed scheme and baseline protocols. The simulation results show that our scheme can optimize the reliable performance for safety related applications. Besides, a lower collision probability leads to fewer retransmissions before each successful transmission, therefore, our proposed scheme can provide low latency performance as is shown by the analysis and simulations.