Wireless identification systems and protocols

• US 20070008069A1
• Filed: 04/17/2006
• Published: 01/11/2007
• Est. Priority Date: 06/14/2001
• Status: Abandoned Application

• Current Assignee: Dean Freiwald, James Rodgers, Roc Lastinger, William Fowler
• Original Assignee: Dean Freiwald, James Rodgers, Roc Lastinger, William Fowler
• Inventors: Rodgers, James, Lastinger, Roc, Fowler, William, Freiwald, Dean
• Application Number:
  US11/406,509
• Publication Number:
  US 20070008069A1
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

Monitoring systems and protocols are disclosed that are flexible in mode operation and format depending on the environment in which they are used. Such monitoring systems and protocols are able to change their utilization automatically, or by received instruction to do so. A location detection system includes one or more low frequency transmitters, one or more radio frequency monitoring tags and one or more receiving devices. The low frequency transmitter transmits location identification information, such as the transmitter ID, to a tag in the vicinity of the transmission. The tag relays the transmitter ID using a higher frequency transmission sent from the tag to the receiver. Communication protocols are disclosed that enable deciphering of multiple tag transmissions starting simultaneously.

Claims

1. In a system for monitoring location of tags, a method performed by a tag for transmitting a tag message, the method comprising:

determing whether the tag has been moved since an immediately prior tag message transmission; and

if it is determined that the tag has been moved, then beginning transmitting the tag message without awaiting lapse of an intermessage gap;

otherwise, beginning transmitting the tag message after lapse of the intermessage gap.