Analytical transmit power adjustment in cooperative vehicle safety systems

Vehicular ad hoc networks (Vanets) play a critical role in enabling essential emergency safety applications (e.g., Forward Collision Warning) and subsequently help the driver deal with emergency situations, These emergency applications have strict different QoS requirements mainly on latency time [1]. In this work, we propose a Power Control Scheme, called PCS that adjusts the transmission power level to guarantee short delays for safety messages over 802.11p/DSRC, especially for occasional emergency messages. PCS aims to minimize contention within two-hop neighborhood of a vehicle under high-offered load conditions. Numerical results show the effectiveness of PCS scheme when coupled with either the traditional random access mechanism [2] or the priority-aware deterministic access protocol based on 802.11p/DSRC [3].