Beaconing from connected vehicles: IEEE 802.11p vs. LTE-V2V

In a near future, vehicles will be equipped with wireless communications technologies to periodically broadcast information to their neighbors on their position and speed. The messages carrying such information, normally denoted as beacons, will reduce the probability of accidents and improve the safety of drivers and passengers. The main candidate technologies for this scope today are IEEE 802.11p and LTE-Advanced with device-to-device communications (LTE-D2D), which is now evolving into vehicle-to-vehicle communications features (LTE-V2V). The aim of this paper is thus to compare the performance in terms of scalability of these two technologies when used for beacon transmission. The comparison is made analytically, through the definition of common scenario and metrics.