V2V for Vehicular Safety Applications

Low delay and high reliability of safety broadcast messages are critical to future intelligent transport systems (ITS). The main objective of this paper is to propose a novel safety broadcast system model to satisfy the latency and reliability requirements of vehicle-to-vehicle (V2V) applications. Second, using this proposed model, a comprehensive performance evaluation is conducted under different technologies (cellular and IEEE 802.11p) for different vehicle densities in rural and urban scenarios based on a realistic system-level simulator. The performance is further improved by using application layer raptor Q codes as compared to the standard repetition codes proposed in the literature. Results show a coverage improvement of 144 m (rural) and 45 m (urban) using cellular V2V with raptor Q codes as compared to IEEE 802.11p for a target end-to-end delay of 5 ms. This is because IEEE 802.11p suffers from preamble channel estimation especially in urban areas with high collision rate due to the hidden terminal problems. In case of a traffic jam, with higher vehicle density, full duplex (FD) operation is needed for cellular V2V to achieve the target delay. FD operation satisfies the latency requirements even when half the resources are available for V2V transmissions.