Decentralized Congestion Control Algorithm for Vehicle to Vehicle Networks Using Oscillating Transmission Power

Wireless access in vehicular environments (WAVE) is a vehicle to vehicle (V2V) communications technology which could help prevent up to 82% of non-impaired accidents, according to the US DOT. A 2013 study by the World Health Organization estimated 2,227 road fatalities in 2009 alone. Currently the channel that is responsible for a vehicle's awareness of others suffers from congestion at moderate loads. In this paper we propose a novel method for adjusting the transmission power in a pattern which alternates between high and low powered transmissions. We modify one commonly used decentralized congestion control (DCC) algorithm, LIMERIC, and compare the power adaptation model against two controls. WAVE supports a 300 meter transmission radius, however, less than 200 vehicles can communicate at the target rate of 10 transmissions per second. We demonstrate that our algorithm reduces the number of packets received by distant vehicles, while maintaining a higher packet rate to the closer vehicles, for which a higher rate is more important.