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. 19, 1995
Filed:
Aug. 02, 1993
Richard Mandelbaum, Manalapan, NJ (US);
AT&T Corp., Murray Hill, NJ (US);
Abstract
An updatable, interrogation system is provided for simultaneously interrogating a plurality of portable data cards. Operable over a plurality of radio frequencies, the interrogation system sequentially communicates with each portable data card as it comes within communication range on a first one of the plurality of radio frequencies for determining a unique identification number associated with each data card. Once the identification number for a card is obtained by the interrogation system, a predetermined transaction, such as deactivating an electronic barrier to entering a limited access area, for the holder of the identified card is initiated. The interrogation system then selects and moves with each card to a different one of the plurality of radio frequencies for completing a data transfer portion of the transaction. The interrogation system simultaneously completes each predetermined transaction of reading from and writing data to each one of the plurality of cards while communicating with each card on the respectively selected ones of the plurality of radio frequencies.