Queued Operations in HF/UHF RFID Applications

• US 20080165007A1
• Filed: 12/14/2007
• Published: 07/10/2008
• Est. Priority Date: 12/14/2006
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: DRAGO, Randall Allen, ROSHAN-AFSHAR, Omid, HOCKEY, Theodore
• Granted Patent: US 7,884,702 B2
• Time in Patent Office: Days
• US Class Current: 340/572.1
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• 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 7/10297 arrangements for handling protocols designed for non-contact record carriers such as RFIDs NFCs, e.g. ISO/IEC 14443 and 18092 cryptographic protocols H04L9/00; network security protocols H04L63/00; real-time communication protocols in data switching networks H04L65/00; network protocols for data switching network services H04L67/00
• CPC Class Codes: G06K 7/10435 the interrogation device being positioned close to a conveyor belt or the like on which moving record carriers are passing conveying in accordance with bodily destination marks, see B65G47/46, sorting of objects carrying identity markings, see B07C5/34

Abstract

A method for pipelined processing of access commands to a population of radio frequency identification (RFID) tags is provided. The method includes transmitting a first queued access command to a first tag in the population of RFID tags, transmitting a second queued access command to a second tag in the population of RFID tags, and transmitting a status request command to the first tag. The queued access command causes the first tag to perform an operation and upon completion of the operation, to suspend transaction processing. The second queued access command is transmitted while the first tag is performing the command operation. The status request command causes the first tag to resume normal processing.

Claims

1. A method for pipelined processing of access commands to a population of radio frequency identification (RFID) tags, comprising:

transmitting a first queued access command to a first tag in the population of RFID tags, wherein the queued access command causes the first tag to perform an operation and upon completion of the operation, to suspend transaction processing;

transmitting a second queued access command to a second tag in the population of RFID tags, wherein the second queued access command is transmitted while the first tag is performing the command operation; and

transmitting a status request command to the first tag, wherein the status request command causes the first tag to resume normal processing.

2. The method of claim 1, further comprising:

prior to transmitting a first queued access command, negotiating a handle for each tag in a set of tags in the population of RFID tags.

3. The method of claim 1, wherein the first queued access command is a Queued_Write command.

4. The method of claim 1, wherein the first queued access command is a Queued_BlockWrite command.

5. The method of claim 1, wherein the first queued access command is a Queued_BlockErase command.

6. The method of claim 1, further comprising:

transmitting a continuous wave (CW) signal to the population of RFID tags simultaneously with transmitting the first queued access command and the second queued access command.

7. The method of claim 1, wherein the population of tags includes more than 25 tags.

8. A method for pipelined processing of access commands to a population of radio frequency identification (RFID) tags, comprising:

receiving a queued access command;

performing an operation in response to the first command; and

upon completion of command operation, suspending processing of transactions.

9. The method of claim 8, further comprising:

receiving a status request command; and

resuming normal operations.

10. The method of claim 8, wherein the queued access command is a Queued_Write command.

11. The method of claim 8, wherein the queued access command is a Queued_BlockWrite command.

12. The method of claim 8, wherein the queued access command is a Queued_BlockErase command.

13. The method of claim 8, further comprising:

generating a pseudorandom number; and

transmitting the pseudorandom number to an interrogator, wherein the pseudorandom number is used as a handle for subsequent commands.

14. An interrogator for pipelined processing of access commands to a population of radio frequency identification (RFID) tags, comprising:

means for sequentially transmitting queued access commands to a set of tags in the population of RFID tags, wherein a queued access command causes a tag to perform an operation and upon completion of the operation, to suspend transaction processing; and

means for sequentially transmitting status request commands to the set of tags in the population of RFID tags, wherein a status request command causes a tag to resume normal processing.

15. The interrogator of claim 14, further comprising:

means for negotiating a handle for each tag in the set of tags in the population of RFID tags.

16. The interrogator of claim 14, wherein the queued access command is a Queued_Write command.

17. The interrogator of claim 14, wherein the queued access command is a Queued_BlockWrite command.

18. The interrogator of claim 14, wherein the queued access command is a Queued_BlockErase command.

19. The interrogator of claim 14, further comprising:

means for transmitting a continuous wave (CW) signal to the population of RFID tags simultaneously with transmitting the queued access commands.

20. A method for pipelined processing of access commands to a population of radio frequency identification (RFID) tags, comprising:

sequentially transmitting a plurality of queued access commands to the population of RFID tags, wherein each queued access command following an initial queued access command is transmitted prior to receipt of a reply to an immediately prior queued access command; and

sequentially transmitting a plurality of status request commands to the population of RFID tags.

21. The method of claim 20, wherein the population of tags includes more than 25 tags.