Oldest packet drop (OPD): A buffering mechanism for beaconing in IEEE 802.11p VANETs (poster)

The IEEE 802.11p MAC technology can be used to provide connectivity for real-time vehicle control known as Cooperative Adaptive Cruise Control. Due to the real-time nature of this system, it is paramount the delay of the received information is as small as possible. This paper researches the Oldest Packet Drop buffering mechanism to increase freshness of beacons compared to the standard EDCA transmission queues, which have a tail-drop policy. We find that using the Oldest Packet Drop buffering mechanism instead of the standard tail-drop can significantly improve the freshness of the received beacons by reducing the queueing delay experienced by the beacons under near-saturation conditions.