Method and system for optimizing an interrogation of a tag population
View Patent ↗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.
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:
(a) estimating a tag population size;
(b) selecting one of a plurality of efficiency profiles based on said estimated tag population size, wherein said efficiency profile defines a number of time slots allocated to one or more read cycles; and
(c) selecting a different efficiency profile based on a duration of said one or more read cycles.
2. The method of claim 1 , wherein step (b) comprises the step of aligning a maximum of one of the plurality of efficiency profiles with the estimated 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 step (b) 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 step (c):
measuring interrogation efficiency during a measurement epoch;
determining whether the measured interrogation efficiency is acceptable; and
repeating steps (a) and (b) if the measured interrogation efficiency is not acceptable.
6. The method of claim 1 , wherein step (c) comprises the steps of:
measuring interrogation efficiency during a measurement epoch;
determining whether the measured interrogation efficiency is acceptable; and
repeating steps (a) and (b) if the measured interrogation efficiency is not acceptable.
7. The method of claim 5 , 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 taken to perform an interrogation of a tag population; and
T min is the minimum possible time required to perform an interrogation of the tag population.
8. The method of claim 5 , wherein the measurement epoch includes one or more interrogations.
9. 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.
10. 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.
11. The method of claim 10 , wherein the hashing code is a cyclic redundancy check (CRC).
12. The method of claim 1 , wherein said number of time slots in a first read cycle is different than said number of time slots in a second read cycle for said selected efficiency profile.
13. The method of claim 1 , wherein said tag address includes a plurality of a sub-address.
14. 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 estimating a tag population size;
means for selecting one of a plurality of efficiency profiles based on said estimated tag population size, wherein said efficiency profile defines a number of time slots allocated to one or more read cycles; and
means for selecting a different efficiency profile based on a duration of said one or more read cycles.
15. The system of claim 14 , wherein said selecting one of a plurality of efficiency profiles means comprises means for aligning a maximum of one of the plurality of efficiency profiles with the estimated tag population size.
16. The system of claim 14 , wherein each of the efficiency profiles provides interrogation efficiency metrics for a plurality of tag population sizes.
17. The system of claim 14 , wherein said means for selecting one of a plurality of efficiency profiles comprises means for allocating a number of time slots to a corresponding one of the plurality of read cycles.
18. The system of claim 14 , wherein said means for selecting a different efficiency profile comprises:
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 taken to perform an interrogation of a tag population; and
T min is the minimum possible time required to perform an interrogation of the tag population.
21. The system of claim 18 , wherein the measurement epoch includes one or more interrogations.
22. The system of claim 14 , 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 14 , 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).
25. The system of claim 14 , wherein said number of time slots in a first read cycle is different than said number of time slots in a second read cycle for said selected efficiency profile.
26. The system of claim 14 , wherein said tag address includes a plurality of a sub-address.