Method and system for inventorying wireless transponders providing anti-eavesdropping anti-collision
First Claim
1. A method for inventorying wireless transponders providing anti-eavesdropping and anti-collision comprising the steps of:
- (a) generating a reader random number at a reader;
(b) transmitting at least a portion of said reader random number from said reader to one or more transponders; and
(c) at each of said one or more transponders, transmitting a response to said reader when at least a portion of a transponder random number generated matches said received portion of said reader random number, said transponder random number being generated at a separate random number generator of said transponder,wherein a length of said reader random number is continuously updated according to the number of said one or more transponders that said reader wants to respond and whether the reader received a response.
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Accused Products
Abstract
The present invention provides one or more powered wireless transponders and/or one or more passive wireless transponder devices communicating with a reader/interrogator and the method of efficiently inventorying these devices without the risk of eavesdropping. A reader transmits a random number and transponders generate their own random number. The transponders whose random number matches all or a part of the random number responds. If a collision occurs, the reader'"'"'s random number can be changed and retransmitted until almost one transponder response is verified in a tree search algorithm. Specifically, the invention concerns a method for inventorying wireless transponders providing anti-eavesdropping anti-collision.
12 Citations
20 Claims
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1. A method for inventorying wireless transponders providing anti-eavesdropping and anti-collision comprising the steps of:
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(a) generating a reader random number at a reader; (b) transmitting at least a portion of said reader random number from said reader to one or more transponders; and (c) at each of said one or more transponders, transmitting a response to said reader when at least a portion of a transponder random number generated matches said received portion of said reader random number, said transponder random number being generated at a separate random number generator of said transponder, wherein a length of said reader random number is continuously updated according to the number of said one or more transponders that said reader wants to respond and whether the reader received a response. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for inventorying wireless transponders comprising:
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a reader; one or more transponders; means for generating a reader random number at said reader; means for transmitting at least a portion of said reader random number from said reader to said one or more transponders; and at each of said one or more transponders, means for transmitting a response to said reader when at least a portion of a transponder random number generated at said transponder matches said received portion of said reader random number, said transponder random number being generated at a separate random number generator of said transponder, wherein a length of said reader random number is continuously updated according to the number of said one or more transponders that said reader wants to respond and whether the reader received a response. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification