Anti-collision coupling for contactless cards
First Claim
1. A method of detecting at least one contactless device that has a unique identification code (UID), the method comprising:
- requesting transfer of a UID;
receiving at least one positive pulse indicative of a UID; and
detecting whether more than one UID was transferred if the number of positive pulses received exceeds the number expected for one UID.
1 Assignment
0 Petitions
Accused Products
Abstract
Contactless cards and a corresponding anti-collision coupling method are provided, where the method includes requesting that the cards transmit their unique identifiers that each include a fixed number of bytes, receiving the unique identifiers simultaneously as byte-wise positive pulses, counting the received positive pulses, and determining that more than one card responded if the number of received positive pulses exceeds the fixed number of bytes; and where the contactless cards each include a unique identifier having a number of bytes, a receiver for receiving an anti-collision command indicative of a desired identifier byte, a comparator in signal communication with the receiver for comparing the desired identifier byte with a corresponding byte of the unique identifier, and a transmitter responsive to the comparator for transmitting the unique identifier as byte-wise positive pulses if the desired identifier byte matches the corresponding byte of the unique identifier.
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Citations
42 Claims
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1. A method of detecting at least one contactless device that has a unique identification code (UID), the method comprising:
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requesting transfer of a UID;
receiving at least one positive pulse indicative of a UID; and
detecting whether more than one UID was transferred if the number of positive pulses received exceeds the number expected for one UID. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of identifying a contactless device having a unique identification code (UID) to a reader, the method comprising:
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receiving a UID call command from a reader; and
transferring at least one positive pulse indicative of the UID to the reader. - View Dependent Claims (11)
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12. A reader for detecting at least one contactless device that has a unique identification code (UID), the reader comprising:
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a UID call commander for requesting transfer of a UID;
a receiver in signal communication with the UID call commander for receiving at least one positive pulse indicative of a UID; and
a detector in signal communication with the receiver for detecting whether more than one UID was transferred if the number of positive pulses received exceeds the number expected for one UID. - View Dependent Claims (13, 14, 15)
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16. A contactless device comprising:
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a memory for storing a unique identification code (UID);
a receiver in signal communication with the memory for receiving a command from a reader;
a command interpreter in signal communication with the receiver for determining whether to transmit the UID; and
a transmitter in signal communication with the memory for transmitting at least one positive pulse indicative of the UID to the reader. - View Dependent Claims (17)
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18. A program storage device readable by a machine to execute program steps for detecting at least one contactless device that has a unique identification code (UID), the program steps comprising:
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requesting transfer of a UID;
receiving at least one positive pulse indicative of a UID; and
detecting whether more than one UID was transferred if the number of positive pulses received exceeds the number expected for one UID. - View Dependent Claims (19)
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20. A program storage device readable by a machine to execute program steps for identifying a contactless device having a unique identification code (UID) to a reader, the program steps comprising:
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receiving a UID call command from a reader;
transferring at least one positive pulse indicative of the UID to the reader;
receiving an anti-collision command and at least one UID value from a reader; and
if the at least one UID value from the reader matches a corresponding portion of the UID of the card, transferring at least one positive pulse indicative of the UID to the reader.
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21. A contactless card, comprising:
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a unique identifier comprising a plurality of bytes;
a receiver for receiving an anti-collision command indicative of at least one desired identifier byte;
a comparator in signal communication with the receiver for comparing the at least one desired identifier byte with at least one corresponding byte of the unique identifier; and
a transmitter responsive to the comparator for transmitting the unique identifier as byte-wise positive pulses if the at least one desired identifier byte matches the at least one corresponding byte of the unique identifier. - View Dependent Claims (22, 23)
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24. A contactless card reader, comprising:
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a transmitter for transmitting an anti-collision command indicative of at least one desired identifier byte;
a receiver for receiving the unique identifier as byte-wise positive pulses if the at least one desired identifier byte matches the at least one corresponding byte of the unique identifier; and
a detector in signal communication with the receiver for detecting a collision when the number of positive pulses exceeds the number of bytes in the unique identifier. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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31. An anti-collision coupling method for contactless cards, the method comprising:
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requesting that the cards transmit their unique identifiers, which each comprises a fixed plurality of bytes;
receiving the unique identifiers simultaneously as byte-wise positive pulses;
counting the received positive pulses; and
determining that more than one card responded if the number of received positive pulses exceeds the fixed plurality of bytes. - View Dependent Claims (32, 33, 34, 35, 36)
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37. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform program steps for anti-collision coupling of contactless cards, the program steps comprising:
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requesting that the cards transmit their unique identifiers, which each comprises a fixed plurality of bytes;
receiving the unique identifiers simultaneously as byte-wise positive pulses;
counting the received positive pulses; and
determining that more than one card responded if the number of received positive pulses exceeds the fixed plurality of bytes. - View Dependent Claims (38, 39, 40, 41, 42)
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Specification