RFID Device Time Synchronization From A Public Source

• US 20110133897A1
• Filed: 02/14/2011
• Published: 06/09/2011
• Est. Priority Date: 11/19/2007
• Status: Active Grant

• Current Assignee: Round Rock Research LLC
• Original Assignee: Round Rock Research LLC
• Inventors: Smith, Freddie W., Ovard, David K., Greeff, Roy Edgar
• Granted Patent: US 8,154,407 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G01D 9/005 Solid-state data loggers
• CPC Class Codes: G06K 19/0716 at least one of the integrated circuit chips comprising a sensor or an interface to a sensor
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card

Abstract

A radio frequency identification (RFID) device includes an antenna linked to a receiving circuit, the antenna tuned to receive a radio frequency (RF) time-code signal from a public source, a controller circuit and an internal clock linked to the receiving circuit, a microcontroller linked to the receiving circuit, a memory linked to the microcontroller, and a battery linked to and powering the receiving circuit, controller circuit, internal clock, microcontroller and memory.

Claims

1. (canceled)

2. A system comprising:

a radio frequency identification (RFID) device comprising;

an antenna tuned to receive a radio frequency (RF) position signal from a public source;

a receiving circuit linked to the antenna, wherein the receiving circuit is configured to convert the received RF position signal into a digital position bit stream;

a controller circuit linked to the receiving circuit, wherein the controller circuit is configured to decode the digital position bit stream; and

an internal clock linked to the controller circuit, wherein a time maintained by the internal clock is updated based on the decoded position bit stream received from the controller circuit.

3. The system of claim 3, further comprising:

an RFID interrogator configured to interrogate the RFID device and receive in response an RFID identification and a time stamp, wherein the time stamp corresponds to the time maintained by the internal clock.

4. The system of claim 4, further comprising:

a subsystem linked to the RFID interrogator, wherein the subsystem is configured to store the RFID identification and the time stamp.

5. A system comprising:

a radio frequency identification (RFID) device comprising;

an antenna tuned to receive a global positioning system (GPS) speed signal from a public source;

a receiving circuit linked to the antenna, wherein the receiving circuit is configured to convert the received GPS speed signal into a digital speed bit stream;

a controller circuit linked to the receiving circuit, wherein the controller circuit is configured to decode the digital speed bit stream; and

an internal clock linked to the controller circuit, wherein a time maintained by the internal clock is updated based on the decoded speed bit stream received from the controller circuit.

6. The system of claim 5, further comprising:

an RFID interrogator configured to interrogate the RFID device and receive in response an RFID identification and a time stamp, wherein the time stamp corresponds to the time maintained by the internal clock.

7. The system of claim 6, further comprising:

a subsystem linked to the RFID interrogator, wherein the subsystem is configured to store the RFID identification and the time stamp.