Data format for efficient encoding and access of multiple data items in RFID tags

• US 7,849,107 B2
• Filed: 05/29/2007
• Issued: 12/07/2010
• Est. Priority Date: 05/26/2006
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Schuessler, Frederick
• Primary Examiner(s): ALAM, SHAHID AL
• Application Number:
  US11/806,050
• Publication Number:
  US 20070276984A1
• Time in Patent Office: 1,288 Days
• Field of Search: 707/803, 707/703, 705/28, 709/231, 711/100, 711/171
• US Class Current: 707/803
• 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

Abstract

Methods and systems for optimizing storage of data items in a memory of a radio frequency identification tag (RFID) are provided. The data structure for optimized storage includes a packed object having a length section including an indication of a number of identifiers in the packed object, an identifier section including a directory of indices representing an identifier for each data item contained within the packed object and a data section encoding a data portion associated with each data item included in the data section.

Claims

1. A data structure stored in a memory of a radio frequency identification (RFID) tag comprising:

a packed object in the memory of the RFID tag, the packed object including;

a length section including an indication of the number of identifiers in the packed object,

an identifier section including a directory of indices representing an identifier for each data item contained within the packed object;

a data section encoding a data portion associated with each data item included in the identifier section;

wherein the packed object provides a complete list of the data items in the data section without requiring a read of the data section; and

at least two or more of the data items are concatenated and encoded as a single unit, and

wherein the at least two of more of the data items comprise items from different data systems.

2. The data structure of claim 1, wherein the identifier section includes a plurality of subsections.

3. The data structure of claim 1, further comprising:

an external directory, wherein a predefined bit pattern at a predefined memory location indicates the inclusion of an external directory in the data structure.

4. The data structure of claim 1, wherein the data section of the packed object includes a plurality of subsections.

5. The data structure of claim 1, wherein the packed object further includes an auxiliary identifier section, wherein the auxiliary identifier section includes additional information required to decode a data item contained with the packed object.

6. The data structure of claim 1, wherein the number of identifiers field is encoded as an extensible bit vector.

7. The data structure of claim 1, wherein the packed object is encoded and decoded in the memory to minimize a number of encoded bits for a given data set that need to be transferred over an air interface.

8. The data structure of claim 1, wherein the RFID tag comprises a Gen 2 tag.

9. The data structure of claim 1, wherein the packed object provides access of each data item included in the identifier section without incurring bit-overhead of adding a full Directory.

10. The data structure of claim 1, wherein each of the data items in the data section is independently encoded.

11. A radio frequency identification (RFID) tag, comprising:

an antenna;

control logic; and

a memory including a data structure embodied thereon, the data structure comprising;

a packed object in the memory of the RFID tag, the packed object including;

a length section including an indication of the number of identifiers in the packed object,

an identifier section including a directory of indices representing an identifier for each data item contained within the packed object;

a data section encoding a data portion associated with each data item included in the identifier section,

wherein the packed object provides a complete list of the data items in the data section without requiring a read of the data section; and

at least two or more of the data items are concatenated and encoded as a single unit, and

wherein the at least two of more of the data items comprise items from different data systems.

12. The RFID tag of claim 11, wherein the packed object is encoded and decoded in the memory to minimize a number of encoded bits for a given data set that need to be transferred over an air interface.

13. The RFID tag of claim 11, wherein the RFID tag comprises a Gen 2 tag.

14. The RFID tag of claim 11, wherein the packed object provides access of each data item included in the identifier section without incurring bit-overhead of adding a full Directory.

15. The RFID tag of claim 11, wherein each of the data items in the data section is independently encoded.

16. A computing device, comprising:

a central processing unit; and

a memory including a data structure embodied thereon, the data structure comprising;

a packed object in the memory of the RFID tag, the packed object including;

a length section including an indication of the number of identifiers in the packed object,

an identifier section including a directory of indices representing an identifier for each data item contained within the packed object;

a data section encoding a data portion associated with each data item included in the identifier section,

wherein the packed object provides a complete list of the data items in the data section without requiring a read of the data section; and

at least two or more of the data items are concatenated and encoded as a single unit, and

wherein the at least two of more of the data items comprise items from different data systems.

17. The computing device of claim 16, wherein the computing device comprises a Gen 2 tag.