The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 2004
Filed:
Jan. 30, 2002
Applicant:
Inventor:
Nikolas Bergerhoff, Regensburg, DE;
Assignee:
Siemens Aktiengesellschaft, Munich, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B 5/22 ; H04B 7/00 ; H04B 1/00 ; H04B 1/06 ; H04B 7/02 ;
U.S. Cl.
CPC ...
G08B 5/22 ; H04B 7/00 ; H04B 1/00 ; H04B 1/06 ; H04B 7/02 ;
Abstract
In the access control system, a code transmitter-end transceiver unit and a vehicle-end transceiver unit emit signals approximately synchronously on approximately the same carrier frequency. As a result of superimposition, a new code signal arises and its code information item is compared with an expected set point code information item. When there is correspondence, an enable signal for locking or unlocking or releasing the immobilizer is generated. The synchronous transmission/reception makes illegitimate monitoring more difficult.