Patent ID: 7859386

Claim:
A method for controlling access to an object, comprising the steps: a) establishing signal communication via electromagnetic waves between the object and a wireless portable unit when a tripping device on the object is actuated, the signal communication comprising identity-based data-carrying signals sent from at least one of the object and the wireless portable unit and the identity-based data contained therein serving to identify the signal-sending device; b) evaluating the distance between the object and the portable unit by measuring the total time for a plurality of said identity-based data-carrying signals to pass between the object and the portable unit; c) evaluating at least one of said identity-based data-carrying signals to determine whether the identity-based data carried therein is correct; and d) authorizing access to the object if said total time is below a predetermined threshold and the identity-based data carried in said at least one evaluated signal is correct.