Adaptive Beacon Rate Adjusting mechanism for safety communication in cooperative IEEE 802.11p-3G vehicle-infrastructure systems

Cooperative active safety applications in WAVE employ periodic beacon broadcasting for status advertisement. High beacon rate enables each vehicle sense the traffic situation from its vicinity promptly. This timely information may assist the driver for safer driving experience. However, high beacon rate will congest the wireless medium due to the contention-based IEEE 802.11p MAC. In this paper, an Adaptive Beacon Rate Adjusting (ABRA) mechanism is proposed and studied. With the help of neural network and back propagation algorithm, a set of guide beacon rates can be obtained adaptively to decrease the performance deterioration caused by congestion. Extensive simulations validate that the proposed mechanism is effective.