RFID device time synchronization from a public source

A radio frequency identification (RFID) device comprising:

• a Global Positioning System (GPS) receiver configured to receive a radio frequency (RF) time-code signal from a Global Navigation Satellite System (GNSS), wherein the GPS receiver is configured to convert the received RF time-code signal into a digital time-code bit stream;
• a controller circuit linked to the GPS receiver, wherein the controller circuit is configured to decode the digital time-code bit stream;
• an internal clock linked to the controller circuit, wherein a time maintained by the internal clock is updated based on the decoded time-code bit stream received from the controller circuit;
• a microcontroller linked to the receiving circuit;
• a memory linked to the microcontroller;
• and
• a battery linked to and powering the GPS circuit, controller circuit, internal clock, microcontroller and memory.

A radio frequency identification (RFID) device comprising:

• a LORAN-C receiver configured to receive a radio frequency (RF) time-code signal, wherein the LORAN-C receiver is configured to convert the received RF time-code signal into a digital time-code bit stream;
• a controller circuit linked to the LORAN-C receiver, wherein the controller circuit is configured to decode the digital time-code bit stream;
• an internal clock linked to the controller circuit, wherein a time maintained by the internal clock is updated based on the decoded time-bit stream received from the controller circuit;
• a microcontroller linked to the receiving circuit;
• a memory linked to the microcontroller;
• and
• a battery linked to and powering the LORAN-C circuit, controller circuit, internal clock, microcontroller and memory.

A radio frequency identification (RFID) device comprising:

• an antenna tuned to receive a radio frequency (RF) time-code signal from a public source;
• a receiving circuit linked to the antenna, wherein the receiving circuit is configured to convert the received RF time-code signal into a digital time-code bit stream;
• a controller circuit linked to the receiving circuit, wherein the controller circuit is configured to decode the digital time-code bit stream;
• an internal clock linked to the controller circuit, wherein a time maintained by the internal clock is updated based on the decoded time-code bit stream received from the controller circuit;
• a microcontroller linked to the receiving circuit;
• and
• a memory linked to the microcontroller.

A method comprising:

• in a radio frequency identification (RFID) device, receiving a radio frequency (RF) time-code signal from a public source;
• converting the received RF time-code signal into a digital time-code bit stream;
• decoding the digital time-code bit stream;
• and
• updating a time maintained by an internal clock based on the decoded time-code bit stream.

A system comprising:

• a radio frequency identification (RFID) device comprising:
• an antenna tuned to receive a radio frequency (RF) time-code signal from a public source,
• a receiving circuit linked to the antenna, wherein the receiving circuit is configured to convert the received RF time-code signal into a digital time-code bit stream,
• a controller circuit linked to the receiving circuit, wherein the controller circuit is configured to decode the digital time-code 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 time-code bit stream received from the controller circuit;
• a 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;
• and
• a subsystem linked to the RFID interrogator, wherein the subsystem is configured to store the RFID identification and time stamp received from the RFID interrogator.