Mobile communicating system with communication unit at road edge

摘要

The units (2) at the road edge interrogate periodically appts (4) fitted to a car (c). When the traffic near the road units is low, a repeated interrogation can lead to a wrong double toll calculation, if the car did not move out of the communication range of the road unit. The wrong toll calculation can be prevented by adjustment of a fixed delay in the car fitted apparatus so that no false toll calculation is possible, when the car passes the same, or another road unit within the delay period. Therefore the road unit calculates a reaction delay of suitable length, based on car speed. The reaction delay is transmitted to the car appts.