Distributed RFID interrogation system and method of operating the same

• US 20070096874A1
• Filed: 10/27/2005
• Published: 05/03/2007
• Est. Priority Date: 10/27/2005
• Status: Abandoned Application

• Current Assignee: WJ Communications, Inc. (Qorvo, Inc.)
• Original Assignee: WJ Communications, Inc. (Qorvo, Inc.)
• Inventors: Mravca, James
• Application Number:
  US11/259,780
• Publication Number:
  US 20070096874A1
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

A system and method are provided for interrogating passive radio frequency identification (RFID) transponders located in compartmentalized areas such as on shelves or in other spatially-partitioned storage areas. The system includes a controller and a plurality of minimal function RFID readers coupled to the controller via a network-compatible cable. The controller is configured to address a subset of at least one reader at a time to interrogate the RFID transponders located in at least one of the compartmentalized areas. The readers are each give a physical location and a unique address, through which the controller would know the locations of the RFID transponders being interrogated.

Claims

1. An RFID reader system comprising:

a controller; and

a plurality of low-power UHF or microwave RFID readers coupled to the controller.

2. The RFID reader system of claim 1 wherein the controller includes a network interface for communicating with the readers.

3. The RFID reader system of claim 2 wherein the network interface is an IEEE 802.3 standard Ethernet interface.

4. The RFID reader system of claim 1 further comprising a network-compatible cable to facilitate communication between the controller and the plurality of RFID readers.

5. The RFID reader of claim 4 wherein each of at least some of the plurality of RFID readers is incorporated into the network compatible cable.

6. The RFID reader system of claim 4 wherein each of the plurality of RFID readers includes an RFID radio coupled to at least one antenna, an Ethernet interface coupled to the network-compatible cable, and an interface module coupled between the RFID radio and the Ethernet interface.

7. The RFID reader system of claim 6 wherein the RFID radio includes registers that can be written to or read from by the controller.

8. The RFID reader system of claim 4 wherein the network-compatible cable includes a plurality of connectable cable sections and at least one adaptor for connecting two neighboring cable sections.

9. The RFID reader system of claim 8 wherein each of at least some of the plurality of RFID readers is incorporated in one of the at least one adaptor.

10. The RFID reader system of claim 8 wherein the at least one adaptor includes two receptors for connecting to respective ones of two neighboring cable sections and a third receptor for connecting with one of the plurality of RFID readers through a network-compatible cable.

11. The RFID reader system of claim 1 wherein each of the plurality of RFID reader has a unique network address.

12. The RFID reader system of claim 1 wherein the controller is configured to address a subset of at least one of the plurality of RFID readers at a time and to cause the at least one RFID reader to transmit interrogation signals.

13. The RFID reader system of claim 12 wherein the controller is configured to generate a reader interface packet to address the subset of the RFID readers.

14. The RFID reader system of claim 13 wherein the reader interface packet is encapsulated in a IEEE 802.3-compliant header.

15. The RFID reader system of claim 1 wherein the controller includes a memory for storing physical locations of the plurality of the RFID readers.

16. The RFID reader system of claim 1 further comprising a plurality of RFID tags with identifications and physical locations known to the controller, at least one of the RFID tags being placed in close proximity to each RFID reader.

17. The RFID reader system of claim 1 wherein the plurality of RFID readers are placed in compartmentalized areas to allow at least one RFID reader in each of the compartmentalized area, and wherein the controller is configured to address each RFID reader individually, and to direct each addressed RFID reader to read or write to RFID tags also placed in the same compartmentalized area with the RFID reader.

18. A method for interrogating RFID tags in compartmentalized areas, comprising:

placing a plurality of RFID readers coupled to a controller through a network interface in the compartmentalized areas;

addressing a first subset of at least one of the plurality of RFID readers from the controller to interrogate RFID tags located in a first subset of at least one of the compartmentalized areas during a first time period; and

addressing a second subset of at least one of the plurality of RFID readers from the controller to interrogate RFID tags located in a second subset of at least one of the compartmentalized areas during a second time period after the first time period.

19. The method of claim 18 wherein the step of placing comprises placing the plurality of the RFID readers in the compartmentalized areas such that at least one of the plurality of RFID readers is situated in each area.

20. The method of claim 18 wherein the plurality of RFID readers are coupled to the controller via a network-compatible cable, and wherein each step of addressing comprises sending from the controller a reader interface packet down the network-compatible cable, the reader interface packet including at least one unique address corresponding to the first or second subset of RFID readers.