Leveraging the Collective Perception Service for CAM Information Aggregation at Intersections

Intersections are prone to accidents due to poor visibility and complex traffic situations. Vehicle-to-X communication enables vehicles to announce themselves by sending Cooperative Awareness Messages or Basic Safety Messages and thus helps to greatly improve the time they are aware of each other before arriving at an intersection. However, similar to the drivers' vision, communication can be obstructed by buildings, too. To mitigate this issue, different approaches to message relaying have been suggested in the past. While they discussed the general idea, this paper gives a detailed proposal on how Road Side Units can aggregate and relay messages using the Collective Perception Service which is currently being standardised. A simulation study analyses the performance of direct and aggregated relaying using a complete ITS-G5 communication stack. Especially, the influence of Decentralized Congestion Control is discussed which earlier studies did not include. It is shown that aggregating Cooperative Awareness information in Collective Perception Messages can greatly improve the drivers' reaction time while at the same time adding only a small amount of load to the communication channel.