Radio frequency identification readers, methods and computer program products for adjusting a query command slot-counter parameter Q
AssigneeAT&T Intellectual Property I, L.P.
InventorsMahmoud Daneshmand, Chonggang Wang
Life of this patent
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Abstract
RFID readers and methods for adjusting a query command slot-count parameter Q for use by radio frequency identification (RFID) tag reader in an RFID tag inventory round are provided. A method for adjusting a query command slot-count parameter Q for use by an RFID tag reader includes setting an initial value for Q for a first inventory round, issuing a query command to a population of RFID tags, and monitoring replies from the population of RFID tags. The value of Q is decreased by a first amount if no reply is received, and the value of Q is increased by a second amount different from the first amount if a tag collision reply is received.
Claims20
A method comprising:
- issuing, via a processor, a query command comprising an initial value for a query command slot-count parameter for a first inventory round to a plurality of radio frequency identification tags;
- identifying, via the processor, replies from the plurality of radio frequency identification tags;
- and
- adjusting, via the processor, the initial value of the query command slot-count parameter for use in a second inventory round by a first amount if no reply is received for the query command that is issued, and by a second amount different from the first amount if a tag collision reply is received for the query command that is issued, wherein the second amount is a lesser of 1.0 and a value of a formula (0.1)*(Ave_Tcoll/Ave_Tidle), wherein Ave_Tcoll is an average duration of a collided reply from the plurality of radio frequency identification tags, and wherein Ave_Tidle is an average duration of no reply from the plurality of radio frequency identification tags, wherein the Ave_T coll is in a range of 581 microseconds to less than 1456 microseconds.
A tangible computer readable medium storing a plurality of instructions which, when executed by a processor, causes the processor to perform operations, the operations comprising:
- issuing a query command comprising an initial value for a query command slot-count parameter for a first inventory round to a plurality of radio frequency identification tags;
- identifying replies from the plurality of radio frequency identification tags;
- and
- adjusting the initial value of the query command slot-count parameter for use in a second inventory round by a first amount if no reply is received for the query command that is issued, and by a second amount different from the first amount if a tag collision reply is received for the query command that is issued, wherein the second amount is a lesser of 1.0 and a value of a formula (0.1)*(Ave_Tcoll/Ave_Tidle), wherein Ave_Tcoll is an average duration of a collided reply from the plurality of radio frequency identification tags, and wherein Ave_Tidle is an average duration of no reply from the plurality of radio frequency identification tags, wherein the Ave_T coll is in a range of 581 microseconds to less than 1456 microseconds.
A radio frequency identification reader, comprising:
- a processor of a radio frequency identification controller;
- a transceiver coupled to the radio frequency identification controller;
- a radio frequency antenna coupled to the transceiver;
- wherein the radio frequency antenna transmits a command received from the processor of the radio frequency identification controller via the transceiver and receives responses from a plurality of radio frequency identification tags;
- and
- wherein the processor of the radio frequency identification controller performs operations, the operations comprising:
- issuing a query command comprising an initial value for a query command slot-count parameter for a first inventory round to a plurality of radio frequency identification tags;
- identifying replies from the plurality of radio frequency identification tags;
- and
- adjusting the initial value of the query command slot-count
- parameter for use in a second inventory round by a first amount if no reply is received for the query command that is issued, and by a second amount different from the first amount if a tag collision reply is received for the query command that is issued, wherein the second amount is a lesser of 1.0 and a value of a formula (0.1)*(Ave_Tcoll/Ave_Tidle), wherein Ave_Tcoll is an average duration of a collided reply from the plurality of radio frequency identification tags, and wherein Ave_Tidle is an average duration of no reply from the plurality of radio frequency identification tags, wherein the Ave_T coll is in a range of 581 microseconds to less than 1456 microseconds.
Dependencies are inferred from the claim text.