Low-cost radio replacement utilizing RFID technology

• US 6,608,551 B1
• Filed: 09/13/1999
• Issued: 08/19/2003
• Est. Priority Date: 09/13/1999
• Status: Expired due to Term

• Current Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Anderson, James A., Wiklof, Christopher A.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US09/394,241
• Time in Patent Office: 1,436 Days
• Field of Search: 340/10.51, 340/10.5, 340/10.1, 340/572.1, 340/7.27, 340/825.36, 340/825.49, 340/825.69, 340/825.72, 455/422, 455/423, 455/425
• US Class Current: 340/10.51
• 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 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas

Abstract

A radio replacement using RFID technology in an RF-enabled device is provided. The RF-enabled handheld, portable, or otherwise mobile device is equipped with an RFID tag having read and write capability. Data exchange occurs between the RFID tag and a network of RFID interrogators placed to provide adequate coverage of the area over which the device might move. As a result of replacing a full functioning transmitting/receiving radio with an RFID tag, the cost of the RF-enabled device could be significantly reduced, its battery life could be extended, and it could operate in a frequency band that does not require FCC approval. Additionally, this invention could provide tracking and access control using the RFID tag and interrogators.

Claims

1. A wireless data communications systems:

a host computer;

an RFID interrogator connected to the host computer, the RFID interrogator adapted to produce a radio frequency magnetic field within a cell; and

a wireless device, including an RFID tag, an input device, a memory, and data buffers;

wherein data input through the input device is stored in the data buffers of the wireless device; and

wherein the RFID tag is adapted to transmit data stored in the data buffers to the host computer, through a wireless communications link between the RFID tag and the RFID interrogator thereby emptying the data buffers, when the device is within the cell.

2. The wireless data communications system of claim 1, wherein the memory is located on the RFID tag.

3. The wireless data communications systems of claim 1, wherein the RFID tag is adapted to receive host data, transmitted to the host computer to the wireless device, through a wireless communications link between the RFID interrogator and the RFID tag, when the wireless device is within the cell.

4. The wireless data communications system of claim 3, wherein the wireless device includes a processor;

and

wherein the host data includes executable code for execution on the processor of the wireless device.

5. The wireless data communications system of claim 3, wherein the wireless device includes a video display;

and

wherein the host data includes visual display data for display on the video display of the wireless device.

6. The wireless data communications system of claim 1, further comprising a plurality of RFID interrogators connected to the host computer, the plurality of RFID interrogators arranged so that their respective cells define a communications area;

wherein a communications link can be established between the wireless device and the host computer through one of the RFID interrogators when the wireless device is within the communications area.

7. The wireless data communications system of claim 6, wherein the host computer includes program logic for determining the cell location of the wireless device within the communications area.

8. The wireless data communications system of claim 7, wherein the program logic further includes logic for tracking the cellular movement of the wireless device within the communications area.

9. The wireless data communications system of claim 8, wherein the program logic further includes logic for determining the location of the wireless device within its current cell location.

10. The wireless data communications system of claim 9, wherein the program logic includes logic for separately interrogating the wireless device through three RFID interrogators, the three RFID interrogators having associated cells adjacent to the current cell location;

and

wherein the location of the wireless device within its current cell is determined by measuring the signal delays between the RFID tag and each of the three RFID interrogators.

11. A wireless data collection device for exchanging data with the host computer connected to a network of RFID interrogators, the wireless data collection device comprising:

an input device;

a data memory;

data buffers for storing data collected by the input device; and

an RFID tag connected to the data buffers for transmitting the stored data to the host computer when interrogated by at least one of the RFID interrogators; and

for emptying the data buffers.

12. The wireless data collection device of claim 11 wherein the input device is a bar code scanner.

13. The wireless data collection device of claim 11 wherein the RFID tag is adapted to receive data downloaded from the host computer via at least one of the RFID interrogators.

14. The, wireless data collection device of claim 13 further comprising:

a processor; and

a program memory for storing program logic for instructing the processor;

wherein the downloaded data comprises executable code which is stored in the program memory for instructing the processor.

15. The wireless data collection device of claim 14 further comprising:

a video display; and

wherein the downloaded data comprises visual display data for display on the video display.

16. A method of tracking a location of a wireless device, said wireless device including an RFID tag and being movable within any one of a plurality of cells, each cell having an associated RFID interrogator adapted to interrogate the RFID tag when physically located within its associate cell, the method comprising the steps of:

locating the wireless device by sequentially interrogating each cell with its associated interrogator until the wireless device responds;

polling the current cell until the wireless device stops responding to the current interrogator;

sequentially interrogating cells adjacent to the current cell until the wireless device is located; and

repeating the steps of polling and sequentially interrogating for the new cell location.

17. The method of claim 16, wherein the step of polling further comprises the steps of:

measuring signal propagation delay from each of three interrogators associated with three adjacent cells; and

comparing the three signal propagation delays to determine the location of the wireless device within the current cell.

18. The method of claim 16, further comprising the step of controlling access privileges of the wireless device based on the location of the RF device.

19. The method of claim 17, wherein data collected by the wireless device may be uploaded to a host computer through the current interrogator and wherein said uploading empties data buffers.

20. The method of claim 17, wherein the step of sequentially interrogating includes the step of:

determining the most likely new cell location of the wireless device based on the last determined location of the wireless device within the current cell.