Improving V2I Edge Communication by Performance Maps

Vehicle-to-infrastructure (V2I) communication is important for the collection of probe vehicle data and traffic information. When using IEEE 802.11 as access technology (ITS-G5 or WAVE), the communication between moving vehicles and fixed infrastructure, such as roadside stations, is most efficient when the passing vehicle reaches a window of opportunity that is characterized by high frame success rates. If the approaching vehicle does not know this window, it might receive a message from a roadside station announcing its presence while at the same time it needs several transmission attempts to transfer data to this roadside station. In this paper we propose a method to overcome this problem: As standard ITS beacon messages contain the geographic locations of the sending vehicles, the roadside station can use this information to create a performance map, which is basically a data structure that shows at which distance a certain frame success ratio can be expected. By disseminating this information (piggybacked to its own beacons), the roadside station can inform approaching vehicles to start transmissions only at those positions, where the expected success rate is high.