Systems and methods for optimizing communications between an RFID reader and a tag population using partial binary tree traversal
First Claim
1. A method in a radio frequency identification (RFID) reader for interrogating an RFID tag population, comprising the steps of:
- (a) reading a first portion of a tag identification bit sequence of tags in the population of tags using a tag interrogation protocol;
(b) causing the tags in the tag population to transition to a state for receiving reader commands;
(c) transmitting a command to cause a first group of tags in the tag population to each set a marker at a specific bit position of their respective tag identification bit sequence and to transition to a state for negotiating a second portion of the tag identification bit sequence; and
(d) reading the second portion of the tag identification bit sequence for a first tag in the first group of tags starting from the marked specific bit position using the tag interrogation protocol.
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Abstract
System and methods for optimizing communications between an RFID reader and a population of tags are described. To increase a read rate, the reader and tags use a partial binary tree traversal. In partial binary tree traversal, a first portion of a tag identification sequence is read. A set marker command is then transmitted to a group of tags causing the tags to set a bit position for start of subsequent binary tree traversal. The subsequent binary tree traversal for the tag group starts at the marked position. Thus, the reader and group of tags negotiate a subset of the identification sequence instead of the entire identification sequence.
44 Citations
20 Claims
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1. A method in a radio frequency identification (RFID) reader for interrogating an RFID tag population, comprising the steps of:
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(a) reading a first portion of a tag identification bit sequence of tags in the population of tags using a tag interrogation protocol;
(b) causing the tags in the tag population to transition to a state for receiving reader commands;
(c) transmitting a command to cause a first group of tags in the tag population to each set a marker at a specific bit position of their respective tag identification bit sequence and to transition to a state for negotiating a second portion of the tag identification bit sequence; and
(d) reading the second portion of the tag identification bit sequence for a first tag in the first group of tags starting from the marked specific bit position using the tag interrogation protocol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method in a radio frequency identification (RFID) tag for communicating with a reader, comprising the steps of:
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(a) engaging in negotiation of a first portion of an identification sequence associated with the tag according to an interrogation protocol;
(b) transitioning to a state for receiving commands from the reader upon receipt of a first sequence of symbols;
(c) receiving a set marker command;
(d) setting a bit position for start of negotiation of a second portion of the identification sequence associated with the tag; and
(e) engaging in negotiation of the second portion of the identification sequence associated with the tag according to the interrogation protocol, wherein the negotiation of the second portion begins at the set bit position. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification