Adaptive Beamforming-Based Gigabit Message Dissemination for Highway VANETs

Millimeter-wave (mmWave) directional communication has been viewed as a means to achieve the goal of multiple gigabit data rate with low latency in vehicular networks, so as to fulfill the requirement of dissemination of a huge amount of sensory data. However, most of the existing researches focus on implementing the vehicular mmWave communications by point-to-point (P2P) transmissions between vehicles or base stations, which is not conductive to efficient dissemination of messages in a whole road segment. In this paper, we propose a novel gigabit message dissemination scheme called P2MP in mmWave/Dedicated Short Range Communications (DSRC) multi-hop vehicle-to-vehicle (V2V) network for highway scenario. P2MP includes: 1) a clustering-based transmitter beamforming method which helps a transmitter to search a relatively optimal transmission beam according to the collected environmental information. 2) a positioning-errors-based receiver beamforming which is used to determine the beam direction and beamwidth at every receiver. 3) a candidate forwarder selection mechanism which is devised to select reliable relays for next hop broadcast. Based on these three components, the proposed P2MP transmission scheme is able to broadcast massive messages to vehicles in the road. The simulation results show that our proposed scheme can effectively improve the efficiency of broadcasting large messages through mmWave.