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:
Feb. 13, 2007
Filed:
Oct. 29, 2004
Li-cheng Richard Zai, Los Gatos, CA (US);
Xinyu Zang, Sunnyvale, CA (US);
Li-Cheng Richard Zai, Los Gatos, CA (US);
Xinyu Zang, Sunnyvale, CA (US);
Other;
Abstract
The system of the present invention includes a large-zone RFID reader, a plurality of small-zone RFID readers, and a plurality of RFID tags. The large-zone RFID reader covers areas which are not covered by the small-zone RFID readers. The output power of the small-zone RFID readers is controlled by the large-zone RFID reader based on RFID tag operation patterns of the small-zone RFID readers. The system reliability is improved by a method that uses reliable RFID tags, RFID reader beacon signals, and RFID tag's repetitive transmitting signals to detect tag failures. The system security is provided by a method that uses integrated crypto engines in both the RFID tags and RFID readers.