RFID tags and readers employing QT command to switch tag profiles

• US 9,024,731 B1
• Filed: 05/22/2013
• Issued: 05/05/2015
• Est. Priority Date: 02/22/2010
• Status: Active Grant

• Current Assignee: Impinj, Inc.
• Original Assignee: Impinj, Inc.
• Inventors: Diorio, Christopher J., Stanford, Theron, Cooper, Scott A., Heinrich, Harley K., Lindhorst, Chad A., Rahimi, Kambiz
• Primary Examiner(s): Wang, Jack K
• Application Number:
  US13/900,443
• Time in Patent Office: 713 Days
• Field of Search: 340/10.51, 340/10.42, 340/10.2, 340/572.8, 340/573.1, 705/26.3, 705/28, 455/404.2
• US Class Current: 340/10.51
• CPC Class Codes: G06K 19/0725 the arrangement being a circuit for emulating a plurality of record carriers, e.g. a single RFID tag capable of representing itself to a reader as a cloud of RFID tags
• CPC Class Codes: G06K 19/07309 Means for preventing undesired reading or writing from or onto record carriers
• CPC Class Codes: G06K 19/08 using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
• 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

Abstract

RFID readers transmit a Quiet Technology (QT) command to RFID tags causing at least one of the tags to transition between a private profile and a public profile. When a tag is inventoried in the private profile, it replies to the reader with contents from its private memory. When a tag is inventoried in the public profile, it replies to the reader with contents from its public memory, where the contents of the public memory may be a subset and/or modified version of the private memory contents, or entirely different altogether. The tag'"'"'s profile can be switched again by another QT command from the reader, or following a loss of power at the tag. An access password and/or a short-range mechanism may be employed to allow only authorized readers to transition tag profiles or interrogate the private memory contents of tags in the public profile.

Claims

1. A Radio Frequency Identification (RFID) reader integrated circuit (IC) comprising:

a communication module for facilitating wireless communication with a plurality of RFID tags; and

a processor configured to;

transmit a first command to at least one of the plurality of tags, the first command causing at least one tag to transition between a private profile and a public profile, wherein the first command includes at least one from a set of;

a read/write field, a persistence field, a payload field, and an RN field, and wherein the at least one RFID tag is adapted to;

when inventoried in the private profile, reply to the reader IC with a first identifier; and

when inventoried in the public profile,

reply to the reader IC with a second identifier,

retain the first identifier,

not reply with the first identifier as long as a tag is in the public profile, wherein the tag is configurable to subsequently return to the private profile and reply with the first identifier; and

employ a first received sensitivity to the first command and a second received sensitivity to a second command, wherein the first sensitivity is greater than the second sensitivity; and

transmit the second command causing the plurality of RFID tags to return to the private profile.

2. The RFID reader IC of claim 1, wherein the first and second commands employ a same command code.

3. The RFID reader IC of claim 1, wherein the at least one RFID tag temporarily transitions from one of the private profile and the public profile to another one of the private profile and the public profile, and reverts back upon losing power.

4. The RFID reader IC of claim 1, wherein the at least one RFID tag is configurable to transition between the private and public profiles only after receiving and verifying a password from the reader IC and to not transition otherwise.

5. The RFID reader IC of claim 1, wherein the first command further causes the tag to report its current profile to the reader IC.

6. The RFID reader IC of claim 1, wherein the first command further causes the tag to transmit a subportion of its memory contents to the reader IC, the subportion indicated by the first command.

7. The RFID reader IC of claim 1, wherein a plurality of contents of the read/write field cause the at least one RFID tag to perform one of:

read control data from tag memory; and

write control data to tag memory.

8. A method for a Radio Frequency Identification (RFID) reader integrated circuit (IC) to communicate with a plurality of RFID tags, the method comprising:

transmitting from a reader IC a command, the command causing at least one of the plurality of tags to transition between a private profile and a public profile, wherein the command includes at least one from a set of;

a read/write field, a persistence field, a payload field, and an RN field;

receiving a reply from the at least one tag with a first identifier when the tag is inventoried in the private profile;

receiving a reply from the at least one tag with a second identifier when the tag is inventoried in the public profile, wherein the at least one RFID tag is adapted to

retain the first identifier when inventoried in the public profile;

not reply to the reader IC with the first identifier as long as the at least one tag is in the public profile, wherein the at least one tag is configurable to subsequently return to the private profile and reply with the first identifier; and

employ a first received sensitivity to the command at the tag in the public profile and employ a second received sensitivity to the command at the tag in the public profile, wherein the second sensitivity is lower than the first sensitivity; and

transmitting a subsequent command and causing the at least one RFID tag to return to the private profile in response to the subsequent one of the command.

9. The method of claim 8, wherein the tag is configurable to transition between the private and public profiles only after receiving a password from the reader IC that matches another password stored on the at least one RFID tag.

10. The method of claim 8, further comprising causing the at least one RFID tag to perform at least one from a set of:

transitioning from one of the private profile and the public profile to another one of the private profile and the public profile;

reporting its current profile to the reader IC;

transmitting a selected portion of tag memory contents; and

reverting back upon losing power.

11. The method of claim 10, wherein a portion of the tag memory contents is indicated by the command.

12. The method of claim 8, wherein a plurality of contents of the read/write field cause the at least one RFID tag to perform one of:

reading control data from tag memory; and

writing control data to tag memory.

13. The method of claim 12, wherein a plurality of contents of the persistence field cause the at least one RFID tag to write the control data to one of:

a tag volatile memory and a tag nonvolatile memory.

14. The method of claim 8, wherein a plurality of contents of the RN field cause the at least one RFID tag to ignore the command if the command lacks a valid handle.

15. The method of claim 8, wherein a plurality of contents of the payload field cause the at least one RFID tag to perform at least one from a set of:

reducing tag sensitivity to the command; and

switching a tag profile.

16. The method of claim 8, wherein the command further indicates a tag memory portion to be rendered unreadable when the at least one RFID tag is in the public profile.

17. The method of claim 8, wherein the command includes a 1 bit read/write field, a 1 bit persistence field, a 16 bit payload field, and a 16 bit RN field.

18. A plurality of Radio Frequency Identification (RFID) tag ICs communicating with a reader and implemented in a system being capable of causing at least one of the tag ICs to transition between two profiles, the system comprising:

a processor configured to transmit a high-down transmission to control a utility in a first manner for transmitting one of a first comment and a second command, the commands including a persistence field to a plurality of tag ICs, the first manner including one of;

installing, enabling, configuring, operating, and disabling the utility, wherein command causes the at least one of the tag ICs to transition into one of a public profile and a private profile, wherein an at least one RFID tag IC is adapted to;

when inventoried in the private profile, reply to the reader with a first identifier; and

when inventoried in the public profile,

reply to the reader with a second identifier,

retain the first identifier, and

not reply with the first identifier as long as the tag IC is in the public profile, wherein the tag IC is configurable to subsequently return to the private profile and reply with the first identifier;

responsive to a plurality of contents of the persistence field, the tag IC writes a control data to one of;

a tag IC volatile memory and a tag IC nonvolatile memory; and

responsive to the high-down transmission, transmitting a low-down transmission to control the utility in the first manner, the low-down transmission being encoded differently than a high-down transmission at least in part, wherein at least one of a first and second commands includes a payload field causing the tag IC to reduce its sensitivity to at least one of the first and second commands.

19. The RFID tag IC system of claim 18, wherein a low-up transmission is received responsive to transmitting the low-down transmission, and responsive to receiving the low-up transmission a high-up transmission is transmitted.

20. The RFID tag IC system of claim 18, wherein a plurality of contents of the payload field further cause the tag IC to switch its current profile.

21. The RFID tag IC system of claim 18, wherein the tag IC ignores the first command if a plurality of contents of an RN field are not a valid handle.

22. The RFID tag IC system of claim 18, wherein the first command includes a 1 bit read/write field, a 1 bit persistence field, a 16 bit payload field, and a 16 bit RN field.

23. The RFID tag IC system of claim 18, wherein the first command further indicates a tag IC memory portion to be rendered unreadable when the tag IC is in the public profile.

24. The RFID tag IC system of claim 18, wherein the first command causes the at least one tag IC to transition between the private and public profiles only after receiving a password from the reader that matches another password stored on the tag IC.