Method, devices and system for multiple RFID tag read-out

• US 7,872,581 B2
• Filed: 09/28/2007
• Issued: 01/18/2011
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Naukkarinen, Santtu Teemu Olavi, Darianian, Mohsen
• Primary Examiner(s): GOINS, DAVETTA WOODS
• Application Number:
  US11/864,135
• Publication Number:
  US 20090085738A1
• Time in Patent Office: 1,208 Days
• Field of Search: 340/572.1, 340/572.4, 340/572.8, 340/10.3, 340/10.34, 340/10.4, 340/10.5, 340/5.92, 235/435, 235/492
• US Class Current: 340/572.1
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G06K 17/0022 arrangements or provisious for transferring data to distant stations, e.g. from a sensing device "transfer between computer elements G06F13/00 "; data-transmission H04L
• 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 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management

Abstract

A method is provided, comprising transmitting a first radio frequency identification tag wake-up sequence by a master reader device; responsive to said first wake-up sequence, transmitting a second radio frequency identification tag wake-up sequence by at least one slave reader device; responsive to receiving said first and/or said second wake-up sequence at one or more radio frequency identification tags of a plurality of radio frequency identification tags, responding to said wake-up sequence; receiving responses from said one or more radio frequency identification tags at said master reader; deriving first tag information from said responses; and providing said first tag information. A corresponding system, master reader device and slave reader device are also provide.

Claims

1. Method, comprising

transmitting a first radio frequency identification tag wake-up sequence by a master reader device;

responsive to receipt of said first wake-up sequence, transmitting a second radio frequency identification tag wake-up sequence by at least one slave reader device;

responsive to receiving said first and/or said second wake-up sequence at one or more radio frequency identification tags of a plurality of radio frequency identification tags, responding to either said first or second wake-up sequence;

receiving responses from said one or more radio frequency identification tags at said master reader;

deriving first tag information from said responses at said master reader; and

said master reader being provided with said first tag information.

2. Method according to claim 1, further comprising

receiving one or more responses from said plurality of radio frequency identification tags at said slave reader;

deriving second tag information from said responses;

storing said second tag information; and

providing said stored second tag information.

3. Method according to claim 2, further comprising

responsive to completion of receiving said responses and storing of said second tag information, communicating an acknowledgement indicating said completion from said at least one slave reader device to said master reader device.

4. Method according to claim 2, wherein said stored second tag information is provided to said master reader device, further comprising

providing said second tag information by said master reader.

5. Method according to claim 2, wherein said stored second tag information is provided to a mobile reader device by said master reader device or said at least one slave reader device.

6. Method according to claim 4, further comprising

requesting second tag information from said at least one slave reader device by said master reader device;

receiving second tag information from said at least one slave reader device; and

providing said second tag information.

7. Method according to claim 4, wherein at least two slave reader devices provide their respective stored second tag information to said master reader device, the method further comprising

determining the position of at least one radio frequency identification tag from said plurality of radio frequency identification tags, based on tag information related to said at least one tag provided by said at least two slave reader devices.

8. Method according to claim 7, wherein at least three slave reader devices provide their respective stored second tag information to said master reader device, wherein the tag information provided by each of said at least three slave reader devices includes a received signal strength indication related to said at least one tag, and wherein the position of said at least one tag is determined based on said strength indication.

9. Computer readable medium storing instructions for instructing a controller to perform the method of claim 1.

10. System, comprising

at least one master reader device having a first coverage area and having

a radio interface;

a network interface;

a controller; and

a power source;

at least two slave reader devices arranged within the first coverage area and each having a second coverage area and each having

a radio interface; and

a controller;

at least a first plurality of radio frequency identification tags arranged within said second coverage area;

wherein

said master reader controller is configured to transmit a first radio frequency identification tag wake-up sequence and to receive responses from said at least first plurality of radio frequency identification tags, to derive tag information from received responses, and to provide said tag information via said network interface; and

said slave reader controller is configured to transmit, responsive to said first radio frequency identification tag wake-up sequence, a second radio frequency identification tag wake-up sequence, using said radio interface, and

wherein said master reader controller is further configured for determining the position of at least one radio frequency identification tag from said at least the first plurality of radio frequency identification tags, based on tag information related to said at least one tag provided by said at least two slave reader devices.

11. System according to claim 10, wherein at least part of said second coverage area is located outside said first coverage area.

12. System according to claim 10, wherein said slave reader controller is further configured to provide said first and said second tag information to a reader device, via said radio interface.

13. System according to claim 10, wherein said at least one slave reader device further comprises

a memory;

wherein said slave reader controller is configured to receive responses from said at least first plurality of radio frequency identification tags through said radio interface, to derive tag information from said responses, to store said tag information in said memory, and to provide said tag information responsive to a request from a reader device.

14. System according to claim 13, wherein said slave reader controller is configured to provide said stored tag information responsive to a request from said at least one master reader device.

15. System according to claim 13, wherein said slave reader controller is configured for communicating, responsive to completion of receiving said responses and storing said tag information, an acknowledgement indicating said completion via said radio interface to said at least one master reader device.

16. System according to claim 10, wherein said slave reader controller is configured for forwarding an instruction for setting said at least first plurality of radio frequency identification tags into a silent mode, using said radio interface.

17. System according to claim 10, comprising at least three slave reader devices, wherein the tag information provided by each of said at least three slave reader devices includes a received signal strength indication related to said at least one tag, and wherein the master reader controller is configured for determining the position of said at least one tag based on said strength indication.

18. System according to claim 10, further comprising a mobile reader device located within the coverage range of at least one of said slave and master reader devices, wherein said mobile reader device is configured to communicate with said at least one of said slave and master reader devices.

19. System according to claim 18, wherein said mobile reader device is configured to enter a listening mode upon detecting a radio frequency field from said slave or master reader devices.

20. System according to claim 18, wherein said slave reader devices are configured to transmit or relay tag information to said mobile reader device.

21. System according to claim 20, wherein said mobile reader devices are configured to request tag information from said slave or master reader devices, and are further configured to receive said requested tag information in response.

22. Master reader device having a first coverage area and having

a radio interface;

a network interface;

a controller; and

a power source;

wherein said master reader is configured to be used in a system having at least two slave reader devices and

at least a first plurality of radio frequency identification tags,

wherein said at least two slave reader devices are arranged within the first coverage area and having a second coverage area and having

a radio interface; and

a controller;

and wherein said at least one first plurality of radio frequency identification tags are arranged within said second coverage area;

wherein

said master reader controller is configured to transmit a first radio frequency identification tag wake-up sequence and to receive responses from said at least first plurality of radio frequency identification tags, to derive tag information from received responses, and to provide said tag information via said network interface; and

wherein in said system said slave reader controller is configured to transmit, responsive to said first radio frequency identification tag wake-up sequence, a second radio frequency identification tag wake-up sequence, using said radio interface, and

wherein said master reader controller is further configured for determining the position of at least one radio frequency identification tag from said at least first plurality of radio frequency identification tags, based on tag information related to said at least one tag provided by said at least two slave reader devices.