Cooperative vehicle collision avoidance using inter-vehicle packet forwarding

This paper proposes a broadcast based packet forwarding mechanism for intra-platoon cooperative collision avoidance (CCA) using dedicated short range communication (DSRC) links. The paper first motivates the needs for broadcast forwarding as opposed to unicast routing for transporting inter-vehicle data for safety-critical applications. Then it introduces an implicit acknowledgement mechanism for reducing the amount of broadcast traffic for enhanced packet delivery rate. We have developed a discrete event hybrid simulator InventSim, which is capable of jointly simulating DSRC based vehicular wireless networks, highway vehicle traffic with car following logic and various drivers´ reaction models, and ITS application interface to the wireless network. Performance of the proposed broadcast forwarding for a CCA system has been characterized using InventSim. Reported results demonstrate that with inter-vehicle spacing of nearly one second, the proposed mechanism is capable of saving up to 90% of vehicles in a platoon from chain crashes following emergency events at the front of the platoon. The system has been also evaluated for a wide range of parameters including vehicle spacing, drivers´ reaction time, and the amount of background non-CCA traffic