×

Read cycles for identifying RFID tags

  • US 9,830,482 B2
  • Filed: 09/14/2015
  • Issued: 11/28/2017
  • Est. Priority Date: 09/12/2014
  • Status: Active Grant
First Claim
Patent Images

1. A method implementing a read cycle for identifying RFID tags among a plurality of RFID tags, each RFID tag having an identifier, the read cycle comprising:

  • (a) selecting a first group of items for reading and, using an RFID reader, receiving identifiers from one or more items of the first group where at least two items appear in a single aggregate data instance at least once;

    (b) performing a first combined read using the received identifiers of the first group by summing values of an RF signal from multiple tags that have broadcast simultaneously in the same time slot to produce a collision;

    (c) storing the first combined read;

    (d) selecting a second group of items for reading and, using an RFID reader, receiving identifiers from one or more items of the second group, where the second group may or may not be different from the first group;

    (e) performing a second combined read using the received identifiers of the second group by summing values of an RF signal from multiple tags that have broadcast simultaneously in the same time slot to produce a collision;

    (f) comparing the first combined read with the second combined read without knowing a-priori connections between placement of different tags; and

    if the result of step (f) is within a margin, terminating the read cycle;

    orif the comparison is not within the margin, repeating steps (a) through (f) by forming at least one new group that may be a subset of the first group and(g) repeating steps (a) through (f) treating the at least one new group as the first group, and performing step (e) by adjusting the second group to exclude corresponding items of the first group that are not in the second group; and

    repeating through step (g) as required to determine what RFID tag of the first group has been added, modified or subtracted with respect to the first group.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×