Tracking variable conditions using radio frequency identification

• US 7,659,823 B1
• Filed: 03/20/2007
• Issued: 02/09/2010
• Est. Priority Date: 03/20/2007
• Status: Active Grant

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Inventors: Rice, Christopher, Killian, Thomas
• Primary Examiner(s): Tweel, Jr., John A
• Application Number:
  US11/725,776
• Time in Patent Office: 1,057 Days
• Field of Search: 340/572.1, 340/10.41, 340/505, 340/539.1, 340/825.69, 340/825.72, 700/215, 700/225
• US Class Current: 340/572.4
• CPC Class Codes: G06K 19/0717 the sensor being capable of sensing environmental conditions such as temperature history or pressure
• CPC Class Codes: H04Q 2209/47 using RFID associated with sensors
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A method and system for tracking variable conditions using radio frequency identification (RFID) are disclosed. In embodiments of the present invention, an RFID sensor tag is used to measure a condition. The condition can be any measurable condition such as location, temperature, humidity, pressure, time, date, inertial measurements, etc. Variable data representing the measured condition is read from the RFID sensor tag in order to track the measured condition. The variable data can be read from RFID sensor tags in addition to reading tag identification data from RFID tags, so that the variable data can be associated with tag identification data.

Claims

1. A method of operation of an RFID tag comprising:

measuring a condition at the RFID tag; and

transmitting a response signal including variable data representing the measured condition to an RFID reading device in response to a radio frequency interrogation signal, said response signal further including non-variable data identifying the variable data as measured data and identifying the type of measured condition represented by the variable data.

2. The method of claim 1, wherein said step of transmitting a response signal comprises:

combining the non-variable data and the variable data into a format of tag identification data; and

transmitting the combined non-variable data and variable data to said RFID reading device.

3. The method of claim 1, wherein said step of measuring a condition at the RFID tag comprises:

measuring the condition at the RFID tag in response to said radio frequency interrogation signal.

4. The method of claim 1, wherein said step of measuring a condition at the RFID tag comprises:

measuring the condition at the RFID tag at a regular time interval; and

storing variable data resulting from a most recent measurement of the condition.

5. The method of claim 4, wherein said step of transmitting a response signal comprises:

transmitting a response signal including the variable data resulting from the most recent measurement of the condition.

6. A method of operating an RFID reader device comprising:

transmitting a radio frequency interrogation signal;

receiving a plurality of response signals each from one of a plurality of RFID tags in response to said radio frequency interrogation signal, at least one of the plurality of response signals including variable data representing a measurement taken by a first one of the plurality of RFID tags, and at least one of the plurality of response signals including tag identification data of a second one of the plurality of RFID tags;

storing the variable data and the tag identification data in a database; and

associating the tag identification data of the second one of the plurality of RFID tags with the variable data representing the measurement taken by the first one of the plurality of RFID tags.

7. The method of claim 6, wherein said at least one of the plurality of response signals including variable data further includes non-variable data identifying the variable data as measured data.

8. The method of claim 7, wherein said non-variable data identifies the type of measurement represented by the non-variable data.

9. The method of claim 7, wherein the non-variable data and the variable data are combined in a format of tag identification data.

10. The method of claim 6, wherein said step of associating the tag identification data of the second one of the plurality of RFID tags with the variable data representing the measurement taken by the first one of the plurality of RFID tags comprises:

associating the tag identification data with the variable data based on database timestamps assigned to the tag identification data and the variable data.

11. An RFID sensor tag comprising:

means for measuring a condition at the RFID sensor tag; and

means for transmitting a response signal including variable data representing the measured condition to a RFID reading device in response to a radio frequency interrogation signal, said response signal further including non-variable data identifying the variable data as measured data and identifying the type of measured condition represented by the variable data.

12. The RFID sensor tag of claim 11, wherein said means for transmitting a response signal comprises:

means for combining the non-variable data and the variable data into a format of tag identification data; and

means for transmitting the combined non-variable data and variable data to said RFID reading device.

13. The RFID sensor tag of claim 11, wherein said means for measuring a condition at the RFID tag comprises:

means for measuring the condition at a regular time interval; and

means for storing variable data resulting from a most recent measurement of the condition.

14. An RFID sensor tag comprising:

an antenna;

a sensing apparatus for measuring a condition at said RFID sensor tag; and

an RF transceiver connected to said antenna for transmitting a radio frequency response signal comprising variable data representing the measured condition to an RFID reader in response to a radio frequency interrogation signal, said response signal further including non-variable data identifying the variable data as measured data and identifying the type of measured condition represented by the variable data.