Speed-Aware V2X Congestion Control

None of the current V2X congestion control standards on the wireless medium access layers have provisions for the speed difference of vehicles. The situations where vehicles have wildly different speeds are more common than not. Even if a more recent ETSI standard specifies facilities layer congestion control that considers the vehicle speed, the access layer congestion control that performs gate-keeping is still speed-agnostic and can cause safety problems. Therefore, the access layer congestion control standards should also be generalized to cater to the safety communication requirement associated with vehicle speed. In this paper, we propose a new access layer congestion control for V2X communication that accounts for the speed difference between vehicles. We demonstrate such a scheme can effectively differentiate the congestion control based on speed differences, facilitating driving safety especially for high-speed vehicles passing by low-speed vehicles.