Patent ID: 6834179
Filing Date: 2004-12-21
Classification: B60R,G07C

Abstract:
A method of operating an access control system, the access control system including:a first transceiver unit in a portable code transmitter configured to emit a first signal upon being triggered; and a second transceiver unit in an access-controlled system configured to emit a second signal upon being triggered; the method which comprises the following steps: emitting the first signal with the first transceiver unit and, at least partially simultaneously and at a substantially equal carrier frequency, emitting the second signal with the second transceiver unit, whereby a superposition of the first signal and the second signal forms a code signal; extracting a code information item from the code signal; and comparing the extracted code information item with a set point code information item, and generating an enable signal if correspondence is determined between the code information item and the set point code information item.