Connectivity based transmit power control in VANET

Real-time safety message exchanging is one of the most important issues in Vehicular Ad-hoc NETwork (VANET), and safety message exchanging mostly happens between close neighbors. Based on this character, this paper presents a novel power control method based on connectivity, which decreases the access delay of safety packets. In the proposed method, the neighbors are weighted according to the relative ranges, moving trend, etc. Comparing the proposed method with conventional fixed transmit power scheme, the average delay is decreased by half, and the packets delay are within 50ms while the vehicles density keep increasing, which achieves the primary application targets of VANET.