Abstract: A mobile communication method wherein a pilot signal is repeatedly transmitted toward a communication zone. As an IU on a vehicle arrives at the communication zone, it transmits a pilot response signal in reply to the pilot signal. When the confirmation antenna receives the pilot response signal, a procedure relating to the confirmation of debiting is executed. When a given time period has passed after this procedure has terminated, the IU transmits an existence-in-second-gantry-zone signal in response to the pilot signal, if the vehicle still exists in the communication zone. By receiving the existence-in-second-gantry-zone signal, it can be ascertained that the vehicle having a confirmed debiting associated therewith exists in the communication zone. Even if a plurality of vehicles are running in the same lane side-by-side, each of these vehicles can be distinguished from one another. The mobile communication method may be similarly applied to any other moving body, as well as to a road vehicle.

Abstract: An automatic debiting system and method suitable for free lane traveling. Debiting antennas disposed on a first gantry are used to communicate with an in-vehicle unit (IU) mounted on the vehicle for debiting. The passages of the vehicles are detected by the loop coils or line scanners, and the license plates, etc., of the vehicles are photographed by the enforcement cameras. Debiting confirmation antennas on second gantry are used to communicate with the IU for the confirmation of debiting. When the normal debiting is confirmed, a local controller informs a system central controller of the fact, whereas when abnormal debiting is confirmed, images of the license plate, etc., of the illegal vehicle are transmitted to the system central controller as illegal vehicle images. The debiting is thus possible at the time of free lane traveling.

Abstract: An interrogation responder system composed of a transmitter stationarily mounted in a certain fixed place and a receiver mounted on a mobile object. The receiver on the mobile side starts the operation when a power is supplied to the entire circuit in accordance with a wake-up signal from the transmitter on the fixed side so as to modulate the electromagnetic signal emitted from the transmitter on the fixed side in accordance with a predetermined code and reflect a response. This enables continuing bilateral communication of a command, data and so forth. By starting communication between the transmitter and the receiver by a direct wave of a carrier signal in a microwave band after sensing that the receiver on the mobile side has entered a good communication zone, secure communication is enabled at a sufficient electric field strength.