Patent US 5,488,360

At a restricted-access facility such as a toll booth, queries are transmitted through an antenna having a restricted zone of transmission and reception. Cellular telephone stations aboard vehicles within this zone of reception respond to the query by transmitting an electronic identification number, which is received by the same or another antenna. The identification number is then encoded in binary format and transmitted by a transceiver connected to the antenna to a computer controller, where the identification number is compared to a list of valid user identification numbers. If the received identification number is found to be valid, the computer controller transmits a "Go" command to the traffic control equipment of the restricted-access facility.