Method and system for optimizing an interrogation of a tag population

• US 20030214389A1
• Filed: 04/01/2003
• Published: 11/20/2003
• Est. Priority Date: 04/01/2002
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Matrics Incorporated (Zebra Technologies Corporation)
• Inventors: Bandy, William R., Arneson, Michael R.
• Granted Patent: US 7,009,496 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management

Abstract

A method and system for optimizing an interrogation of a tag population that includes a plurality of tags, wherein each of the plurality of tags is assigned a tag address includes determining a tag population size; selecting one of a plurality of efficiency profiles that matches the determined tag population size; and defining a plurality of interrogation read cycles according to the selected efficiency profile.

Claims

1. A method of optimizing an interrogation of a tag population that includes a plurality of tags, wherein each of the plurality of tags is assigned a tag address, the method comprising the steps of:

determining a tag population size;

selecting one of a plurality of efficiency profiles that matches the determined tag population size; and

defining a plurality of interrogation read cycles according to the selected efficiency profile.

2. The method of claim 1, wherein said selecting step comprises the step of aligning a maximum of one of the plurality of efficiency profiles with the determined tag population size.

3. The method of claim 1, wherein each of the efficiency profiles provides interrogation efficiency metrics for a plurality of tag population sizes.

4. The method of claim 1, wherein said defining step comprises the step of allocating a number of time slots to a corresponding one of the plurality of read cycles.

5. The method of claim 1, wherein said determining step comprises the steps of statistically estimating the tag population size.

6. The method of claim 1, further comprising the steps of

measuring interrogation efficiency during a measurement epoch;

determining whether the measured interrogation efficiency is acceptable; and

repeating said determining and selecting steps if the measured interrogation efficiency is not acceptable.

7. The method of claim 6, wherein the determining step comprises the step of determining whether the measured interrogation efficiency is greater than a predetermined threshold.

8. The method of claim 6, wherein said measuring step comprises the step of calculating:

E=T_min/T_actual, wherein;

E is the interrogation efficiency;

T_actual is the actual time it taken to perform an interrogation of a tag population; and

T_min. Is the minimum possible time required interrogation the same tag population.

9. The method of claim 6, wherein the measurement epoch includes one or more interrogations.

10. The method of claim 1, wherein the tag address is a UPC code plus a serial number that give substantial uniqueness to all products within that particular UPC code.

11. The method of claim 1, wherein the tag address includes a first portion comprising a hashing code, which is computed from the remainder of the tag address.

12. The method of claim 11, wherein the hashing code is a cyclic redundancy check (CRC).

13. A system for optimizing an interrogation of a tag population that includes a plurality of tags, wherein each of the plurality of tags is assigned a tag address, comprising:

means for determining a tag population size;

means for selecting one of a plurality of efficiency profiles that matches the determined tag population size; and

means for defining a plurality of interrogation read cycles according to the selected efficiency profile.

14. The system of claim 13, wherein said selecting means comprises means for aligning a maximum of one of the plurality of efficiency profiles with the determined tag population size.

15. The system of claim 13, wherein each of the efficiency profiles provides interrogation efficiency metrics for a plurality of tag population sizes.

16. The system of claim 13, wherein said defining means comprises means for allocating a number of time slots to a corresponding one of the plurality of read cycles.

17. The system of claim 13, wherein said determining means comprises means for statistically estimating the tag population size.

18. The system of claim 13, further comprising:

means for measuring interrogation efficiency during a measurement epoch; and

means for determining whether the measured interrogation efficiency is acceptable.

19. The system of claim 18, wherein the determining means comprises means for determining whether the measured interrogation efficiency is greater than a predetermined threshold.

20. The system of claim 18, wherein said measuring means comprises the means for calculating:

E=T_min/T_actual, wherein;

E is the interrogation efficiency;

T_actual is the actual time it taken to perform an interrogation of a tag population; and

T_min. Is the minimum possible time required interrogation the same tag population.

21. The system of claim 18, wherein the measurement epoch includes one or more interrogations.

22. The system of claim 13, wherein the tag address is a UPC code plus a serial number that give substantial uniqueness to all products within that particular UPC code.

23. The system of claim 13, wherein the tag address includes a first portion comprising a hashing code, which is computed from the remainder of the tag address.

24. The system of claim 23, wherein the hashing code is a cyclic redundancy check (CRC).