Reading protocol for transponders of electronic identification system
First Claim
1. A method of reading a plurality of transponders forming part of an electronic identification system also comprising a reader, the method comprising the steps of:
- causing the reader to lock onto a first part of a digital sequence being transmitted by one of said transponders;
causing the reader to broadcast a mute signal to mute all of said transponders not yet transmitting;
causing the reader to transmit a separate first command to cause said one transponder to transmit a remainder of the sequence; and
receiving and reading said remainder of the sequence at the reader.
8 Assignments
0 Petitions
Accused Products
Abstract
A method of reading 8 plurality of transponders 14.1 to 14.n forming part of an electronic radio frequency identification system 10 comprises the steps of prompting the transponders at 38 to transmit preambles 30 only of respective response digital sequences to a reader 12. The reader then locks onto the preamble 30 transmitted by one of the transponders and immediately causes a mute signal 38 to be broadcast to mute all of the transponders not yet transmitting. The reader then transmits during a first time window 42 a first command 40 to cause the one transponder to transmit a remainder of the sequence. Having received and read the remainder, the reader transmits a second command 44 during a second time window 46 to cause the one transponder to switch to a sleep mode wherein the one transponder no longer transmits any part of the sequence, and to unmute the muted transponders.
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Citations
17 Claims
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1. A method of reading a plurality of transponders forming part of an electronic identification system also comprising a reader, the method comprising the steps of:
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causing the reader to lock onto a first part of a digital sequence being transmitted by one of said transponders;
causing the reader to broadcast a mute signal to mute all of said transponders not yet transmitting;
causing the reader to transmit a separate first command to cause said one transponder to transmit a remainder of the sequence; and
receiving and reading said remainder of the sequence at the reader. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An electronic radio frequency identification system comprising:
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a reader;
a transponder population comprising a plurality of transponders to be read by the reader;
the reader comprising a controller, a transmitter for transmitting signals to the transponder population and a receiver for receiving response digital sequences from the transponder population;
the controller being operative to lock onto a first part of a digital sequence being transmitted by one of said transponders;
the controller being operative to cause the transmitter to broadcast a mute signal to mute all of said transponders not yet transmitting;
the controller further being operative to cause the transmitter to transmit a separate first command to cause said one of said transponders to transmit a remainder of the sequence; and
the controller causing the receiver to receive and read said remainder of the sequence. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A reader for an electronic radio frequency identification system comprising:
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a controller;
a transmitter for transmitting signals to a transponder population comprising a plurality of transponders; and
a receiver for receiving response signals from the transponder population;
the controller being operative to lock onto a first part of a digital sequence being transmitted by one of said transponders;
the controller being operative to cause the transmitter to broadcast a mute signal to mute all of said transponders not yet transmitting;
the controller further being operative to cause the transmitter to transmit a separate first command to cause said one of said transponders to transmit a remainder of the sequence; and
the controller causing the receiver to receive and read said remainder of the sequence.
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17. A transponder for an electronic radio frequency identification system, the transponder comprising:
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a modulator for modulating a carrier with response signals;
a demodulator for demodulating command signals; and
a controller for the modulator and demodulator;
the controller being sensitive to a mute command received from a reader and responsive thereto by muting the transponder, and if the mute command is not received, to cause the modulator to modulate the carrier with a first part only of a digital sequence;
the controller further being sensitive to a separate first command signal; and
the controller also being responsive to said first command signal by causing the modulator to modulate the carrier with a remainder of the sequence.
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Specification