Blockage Avoidance Based Sensor Data Dissemination in Multi-Hop MmWave Vehicular Networks

MmWave communication has emerged as a promising technology to fulfill requirements of gigabit-level data rates, so as to support the exchange of large amounts of sensor data in vehicle-to-vehicle (V2V) communications. However, inter-vehicle line-of-sight (LOS) blockages may significantly deteriorate the link quality and lead to data packet loss. Addationally, it is difficult to coordinate directional transmissions to broadcast massive sensor data to nearby vehicles timely for enhanced environmental awareness. To overcome these challenges, this article proposes a blockage avoidance based multi-hop sensor data dissemination (BAMD) scheme in a centralized manner. First, we propose a mmWave LOS link availability identification method based on the geometric relation among vehicles. Second, the problem of sensor data dissemination among all vehicles is formulated aiming at minimizing the overall transmission delay. To find an approximate solution, a novel transmission utility function based multi-hop data dissemination algorithm is designed jointly considering the distance between vehicles, packet queue, the number of LOS neighbors and concurrent transmissions. By theoretical analysis and extensive simulation, it is indicated that the proposed scheme can achieve a reliable and fast sensor data dissemination. In high-density case, BAMD can improve reliability by 20 $\%$ and reduce transmission delay by 82 $\%$ compared with baselines.