VehCom: Delay-Guaranteed Message Broadcast for Large-Scale Vehicular Networks

Timely vehicle-to-vehicle (V2V) communication is a key component of intelligent transportation systems to improve driving safety and efficiency. Although many results have been produced for vehicular networks, most of them focused on improving vehicular communication capacity and reliability. Very limited progress has been made so far in the design of practical V2V communication schemes for large-scale vehicular networks. In this paper, we present VehCom, a fully distributed message broadcast scheme for V2V communication networks. VehCom offers a delay guarantee for each vehicle’s message broadcast while minimizing the packet loss rate. The enabler of VehCom is an asynchronous packet reception technique, which leverages a vehicle’s multiple antennas to decode asynchronous collided packets from its neighboring vehicles. We have implemented the asynchronous packet reception technique on a vehicular wireless testbed, and examined the performance of VehCom in a large-scale vehicular network where i) each vehicle is equipped with four antennas, ii) each vehicle has 240 vehicles in its communication range, and iii) each vehicle broadcasts a 624-bit packet over 10 MHz spectrum in every 100 ms (guaranteed delay). Our experimental and analytical results show that the packet loss rate is less than 3.9% on parking lots, less than 4.1% on local roads, and less than 6.2% on highways.