Methods of identifying RFID tag for preventing RFID tag collision, RFID reader and RFID tag using the same

• US 20100019883A1
• Filed: 11/19/2008
• Published: 01/28/2010
• Est. Priority Date: 07/25/2008
• Status: Abandoned Application

• Current Assignee: Sungkyunkwan University Foundation For Corporate Collaboration (SungKyunKwan University (SKKU))
• Original Assignee: Sungkyunkwan University Foundation For Corporate Collaboration (SungKyunKwan University (SKKU))
• Inventors: Lee, Tae-Jin, Eom, Jun-Bong
• Application Number:
  US12/292,460
• Publication Number:
  US 20100019883A1
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G06K 21/00 Information retrieval from punched cards designed for manual use or handling by machine G06K19/00 takes precedence; detection or correction of errors by rescanning patterns G06V10/98; checking correct operation of card-conveying mechanisms G06K13/06; Apparatus for handling such cards, e.g. marking or correcting
• 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 7/10019 resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. collision between the communication channels used by wireless communication devices, where the solution is not particularly adapted for RFIDs or the like, H04W74/08
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04Q 2213/13003 Constructional details of switching devices

Abstract

A method of identifying a plurality of RFID tags in an RFID reader includes generating a Query command to transmit the Query command to an RFID tag in a ready state, receiving an error detection code from the RFID tag that received the Query command, generating an acknowledgement (ACK) command to transmit the acknowledgement (ACK) command to the RFID tag that transmitted the error detection code when the error detection code is received without a collision, and receiving tag information including a protocol control (PC) and an electronic product code (EPC) of the RFID tag that transmitted the error detection code. It is possible to improve tag identification speed using an error detection code, such as a cyclic redundancy check (CRC)-16 code, which has uniformly-random characteristics like random number with 16 bits (RN 16), instead of RN 16 used in a conventional EPCglobal Class1 Generation2 standard.

Claims

1. A method of identifying a plurality of radio frequency identification (RFID) tags in an RFID reader, comprising:

generating a Query command to transmit the Query command to an RFID tag in a ready state;

receiving an error detection code from the RFID tag that received the Query command;

when the error detection code is received without a collision, generating an acknowledgement (ACK) command to transmit the acknowledgement (ACK) command to the RFID tag that transmitted the error detection code; and

receiving tag information including a protocol control (PC) and an electronic product code (EPC) of the RFID tag that transmitted the error detection code.

2. The method of claim 1, wherein the error detection code is generated using the PC and the EPC of the RFID tag that transmitted the error detection code.

3. The method of claim 2, wherein the error detection code is a cyclic redundancy check (CRC)-16 code.

4. The method of claim 3, further comprising performing, at the RFID reader, a cyclic redundancy check (CRC) using the received CRC-16 code.

5. The method of claim 3, further comprising determining, at the RFID reader, that a collision has occurred when the CRC-16 code is not correctly identified or when a reply to the ACK command is not received from the RFID tag.

6. The method of claim 1, wherein the tag information including the PC and the EPC is transmitted to the RFID reader when the ACK command received by the RFID tag that transmitted the error detection code is valid.

7. The method of claim 1, wherein the tag information does not include the error detection code.

8. The method of claim 7, wherein the error detection code not included in the tag information is a cyclic redundancy check (CRC)-16 code.

9. A method of identifying a radio frequency identification (RFID) tag, comprising:

receiving a Query command from an RFID reader;

transmitting an error detection code to the RFID reader in response to the Query command;

receiving an acknowledgement (ACK) command from the RFID reader that received the error detection code without a collision; and

transmitting tag information including a protocol control (PC) and an electronic product code (EPC) of an RFID tag that transmitted the error detection code to the RFID reader.

10. The method of claim 9, wherein the error detection code is generated using the PC and the EPC of the RFID tag that transmitted the error detection code.

11. The method of claim 10, wherein the error detection code is a cyclic redundancy check (CRC)-16 code.

12. The method of claim 11, wherein the CRC-16 code is used for the RFID reader to perform a cyclic redundancy check (CRC).

13. The method of claim 9, wherein the tag information including the PC and the EPC is transmitted to the RFID reader when the ACK command received by the RFID tag that transmitted the error detection code is valid.

14. The method of claim 9, wherein the tag information does not include the error detection code, and the error detection code not included in the tag information is a cyclic redundancy check (CRC)-16 code.

15. A radio frequency identification (RFID) reader, comprising:

a transceiver configured to transmit and receive signals to and from a plurality of RFID tags; and

a collision processor configured to generate a Query command to transmit the Query command to an RFID tag in a ready state via the transceiver, configured to generate an acknowledgement (ACK) command to transmit the acknowledgement (ACK) command to the RFID tag that transmitted an error detection code via the transceiver when the error detection code is received from the RFID tag that received the Query command via the transceiver without a collision, and configured to receive tag information including a protocol control (PC) and an electronic product code (EPC) of the RFID tag that transmitted the error detection code via the transceiver.

16. The RFID reader of claim 15, wherein the error detection code is a cyclic redundancy check (CRC)-16 code generated using the PC and the EPC of the RFID tag that transmitted the error detection code, and the tag information does not include the CRC-16 code.

17. The RFID reader of claim 16, wherein the RFID reader determines that a collision has occurred when the CRC-16 code is not correctly identified or when a reply to the ACK command is not received from the RFID tag that transmitted the error detection code.

18. The RFID reader of claim 15, wherein the tag information including the PC and the EPC is transmitted to the RFID reader when the ACK command received by the RFID tag that transmitted the error detection code is valid.

19. A radio frequency identification (RFID) tag including a memory storing unique information and an antenna for communication with an RFID reader, the RFID tag receiving a Query command from the RFID reader via the antenna, transmitting an error detection code to the RFID reader via the antenna in response to the Query command, receiving an acknowledgement (ACK) command via the antenna from the RFID reader that received the error detection code without a collision, and transmitting tag information including a protocol control (PC) and an electronic product code (EPC) to the RFID reader via the antenna.

20. The RFID tag of claim 19, wherein the error detection code is a cyclic redundancy check (CRC)-16 code generated using the PC and the EPC of the RFID tag that transmitted the error detection code, and the tag information does not include the CRC-16 code.