Eelctronic Toll Collect (ETC) or Electronic Fee Collection (EFC) are microwave-based radio systems that determine the position of the vehicle. In conjunction with the on-board unit (OBU), the toll can be calculated from the distance travelled and from vehicle-specific data
. In Europe, toll collection systems work with Dedicated Short Range Communication (DSRC) according to IEEE 802.11p
inthe frequency range of 5.8 GHz
. Depending on the concept, the communication of the electronic Toll Collect systems takes place between the vehicle and the radio beacons, which are positioned as Roadside Units (RSU) along the routes. The radio beacons transmit a radio signal that is received by the on-board unit and sent back to the radio beacon modulated with a data signal. To ensure reception, the OBUs use two different modulation methods. The distance can be determined from the stationary position of the radio beacon.