Performance Evaluation of Safe Avoidance Time and Safety Message Dissemination for Vehicle to Vehicle (V2V) Communication in LTE C-V2X

VANET has many opportunities to manage vehicle safety on the road efficiently. The standards from European Telecommunications Standards Institute (ETSI) for Intelligent Transport System (ITS) provide necessary upper-layer specifications for safety message dissemination between vehicles using Cooperative Aware Messages (CAM) and Decentralized Event Notification Message (DENM). Besides, mobile radio technology of Long-Term Evolution (LTE) in Release-14 comes with two modes of communication, which is mode 3 and mode 4 to support vehicle to vehicle communications. The relationship between vehicle time gap, speed, and UE transmit power significantly impacts the Packet Delivery Ratio (PDR) and throughput. With higher vehicle moving speeds, longer safe distances must be kept in ensuring safety. However, at longer safe distances, we have proven that communication may be lost because CAM messages cannot be exchanged successfully. As a result, no vehicle safety can be guaranteed using V2V communication. This may get worse in urban or cities environment where interference is dominant. Simulation results provide evidence that variable distance between vehicles cannot be ignored to ensure vehicle safety with successful message communication among them.