Local processing of received RFID tag responses

• US 8,154,385 B2
• Filed: 06/20/2006
• Issued: 04/10/2012
• Est. Priority Date: 08/31/2005
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Aiouaz, Ali, Dietrich, Paul, Diorio, Christopher J., Cooper, Scott A.
• Primary Examiner(s): Zimmerman, Brian A
• Assistant Examiner(s): Khan, Omer S
• Application Number:
  US11/472,179
• Publication Number:
  US 20070046432A1
• Time in Patent Office: 2,121 Days
• Field of Search: 340/10.1, 340/572.1
• US Class Current: 340/10.1
• 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 7/10108 interrogating only those RFIDs that fulfill a predetermined requirement, e.g. selecting all RFIDs having the same speed and moving in a cloud like fashion, e.g. on the same train; interrogating only RFIDs having a certain predetermined temperature, e.g. in the same fridge, another possibility being the active ignoring of a group of tags that fulfill a predetermined requirement, equivalent to the Boolean NOT operation

Abstract

Radio frequency identification (RFID) tags selected for inventorying using combination of preselect and/or post select criteria. The selection commands can be for selecting according to a tag memory content, by invoking the mask address or by comparing other tag characteristics. Selection criteria can be determined locally at a modem block of a reader or provided to the modem block by higher layers of the reader. Tags meeting the selection criteria are reported to the higher layers for further actions. Some tags may be held while waiting for instructions from the higher layer block(s).

Claims

1. A method for a first layer of a multilayer RFID reader system to process a plurality of received RFID tag responses, the method comprising:

receiving a postselect mask from a second layer;

inventorying a tag population;

receiving a response from a tag;

if the response does not meet a preselect criterion, then discarding the response;

else

reporting the response and applying a postselect criterion by comparing the response to the postselect mask;

if the response meets the postselect criterion then pausing the inventory and handing off control from the first layer to the second layer;

receiving control and instructions back from the second layer; and

performing an access operation on the tag based on the instructions;

then continuing to inventory the tag population.

2. The method of claim 1, in which the postselect mask is derived from a logic combination of masks.

3. The method of claim 1, in which the inventory is paused until expiration of a predetermined waiting period.

4. The method of claim 1, further comprising:

generating associated data for the tag response; and

reporting to the second layer the associated data.

5. The method of claim 4, in which

the associated data includes at least one of:

a time stamp, an indication about a received signal strength of the tag response, an RF channel used by the tag, and an antenna used by the tag.

8. The system of claim 4, in which

the preselect criterion is stored in a local database associated with the first layer.

9. The system of claim 4, in which

the is postselect;

mask is stored in a local database associated with one of the first layer and the second layer.

10. The system of claim 4, in which

the postselect mask is derived from a plurality of logically combined masks.

11. The system of claim 4, in which

the inventory is paused until expiration of a predetermined waiting period.

12. The system of claim 4, in which the first layer is further configured to:

generate associated data for the tag response; and

report to the second layer the associated data.

13. The system of claim 12, in which

the associated data includes at least one of:

a time stamp, an indication about a received signal strength of the tag response, an RF channel being used for communication by the tag, and an antenna type being used by the tag.

6. An RFID reader system for receiving and processing RFID tag responses, comprising:

a first layer; and

a second layer, in which the first layer configured to;

receive a postselect mask from the second layer;

inventory a tag population,

receive a response from a tag,

if the response does not meet a preselect criterion, then discard the response, else

report the response and apply a postselect criterion by comparing the response to the postselect mask;

if the response meets the postselect criterion then

pause the inventory and hand off control to the second layer;

receive control and instructions back from the second layer; and

perform an access operation on the tag based on the instructions;

then continue to inventory the tag population.

7. The system of claim 6, wherein the first layer is a modem, the second layer is a host processor, and wherein the first layer and the second layer communicate through a Modem Application Programming Interface (MAPI).

14. A first layer of a multilayer RFID reader system for receiving and processing RFID tag responses, comprising:

a means for receiving a postselect mask from a second layer;

a means for inventorying a tag population;

a means for receiving a response from a tag;

a means for, if the response does not meet a preselect criterion, discarding the response;

else

reporting the response and applying a postselect criterion by comparing the response to the mask

a means for, if the response meets the postselect criterion, then

pausing the inventorying and handing off control from the first layer to the second layer receiving control and instructions back from the second layer;

performing an access operation on the tag based on the instructions; and

a means for continuing to inventory the tag population.

15. A non-transitory computer-readable storage medium including instructions thereon for a method of processing a plurality of received RFID tag responses at a first layer of a multilayer RFID reader system, the method comprising:

receiving a postselect mask from a second layer;

inventorying a tag population;

receiving a response from a tag;

if the response does not meet a preselect criterion, then discarding the response;

else

reporting the response and applying a postselect criterion by comparing the response to the postselect mask;

if the tag response meets the postselect criterion, then

pausing the inventory and handing off control from the first later to the second layer;

receiving control and instructions back from the second layer; and

performing an access operation on the tag based on the instructions;

then continuing to inventory the tag population.

16. The non-transitory computer-readable medium of claim 15, in which

the postselect mask is derived from a logic combination of masks.

17. The non-transitory computer-readable medium of claim 15, in which

the inventory is paused until expiration of a predetermined waiting period.