Cellular telephone anti-fraud system
First Claim
1. A transmitter identification system comprising:
- a plurality of transmitters each for generating a transmitter signal including internal data traits and external signal traits;
receiving means located remote from said transmitters for receiving, for each of said transmitters, said transmitter signal;
characterizing means connected to said receiving means for characterizing one of said transmitters and for generating a plurality of characterizing signals for said one transmitter, wherein the characterizing means generates said plurality of characterizing signals by measuring features of said external traits of said one of said transmitters from at least one of a first category including variations of specified parameters of said one of said transmitters, and a second category including variations in non-specified parameters; and
converting means connected to said characterizing means for converting said plurality of charaterizing signals into a security pattern wherein said security pattern is used to identify said one of said transmitters.
4 Assignments
0 Petitions
Accused Products
Abstract
A transmitter identification system to determine if cellular phones in a cellular phone system are authorized as distinguished from cloned phones, operated by fraudulent users, that are unauthorized. Components used in the manufacture of cellular phones vary slightly from one phone to anther so that, when the phones are used, the transmitter signals from each phone have different external signal traits. For each cellular phone call, the transmitter signal is received and characterized using a received set of features resulting from the external signal traits. The received set of features is compared with previously stored sets of Features in a database to determine if the call is authorized or unauthorized and, if unauthorized, the call is stopped and access to the fraudulent user is denied.
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Citations
25 Claims
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1. A transmitter identification system comprising:
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a plurality of transmitters each for generating a transmitter signal including internal data traits and external signal traits; receiving means located remote from said transmitters for receiving, for each of said transmitters, said transmitter signal; characterizing means connected to said receiving means for characterizing one of said transmitters and for generating a plurality of characterizing signals for said one transmitter, wherein the characterizing means generates said plurality of characterizing signals by measuring features of said external traits of said one of said transmitters from at least one of a first category including variations of specified parameters of said one of said transmitters, and a second category including variations in non-specified parameters; and converting means connected to said characterizing means for converting said plurality of charaterizing signals into a security pattern wherein said security pattern is used to identify said one of said transmitters. - View Dependent Claims (2, 3, 4)
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5. A transmitter identification apparatus for identifying ones of a plurality of transmitters that may include authorized transmitters and unauthorized transmitters, each transmitter broadcasting a transmitter signal where the transmitter signal is formed by processing information and by manipulating a carrier with the processed information, the transmitter signal including external signal traits resulting from said manipulation that are characteristic of said transmitter, said information containing a transmitter identification code, said apparatus comprising:
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receiving means for receiving said transmitter signal to provide a corresponding received signal including said signal traits, demodulating means for demodulating said received signal to recover the transmitter identification code, and characterizing means for characterizing said signal traits of said received signal to form a received set of features, storing means for storing stored sets of feature information for each transmitter, comparing means for comparing said received set of features with one or more of said stored sets of feature information. - View Dependent Claims (6, 7, 8, 9)
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10. A communication system having a subscriber service for a plurality of transmitters that may include authorized transmitters for authorized users and unauthorized transmitters for unauthorized users, each transmitter broadcasting a transmitter signal where the transmitter signal is formed by processing information and by manipulating a carrier with the processed information, the transmitter signal including external signal traits resulting from said manipulation that are characteristic of said transmitter, said information containing a transmitter identification code, said subscriber service controlling use of the system by users, said communication system comprising:
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transmitter identification apparatus including, receiving means for receiving, for each transmitter, said transmitter signal to provide a corresponding received signal including said signal traits, demodulating means for demodulating, for each transmitter, said received signal to recover the transmitter identification code, characterizing means for characterizing, for each transmitter, said signal traits of said received signal to form a received set of features characterizing each said transmitter, storing means for storing stored sets of features in connection with storage identification codes such that for each storage identification code there may be zero or more first stored sets of features corresponding to an authorized transmitter and zero or more second stored sets of features corresponding to one or more unauthorized transmitters, comparing means for comparing the received set of features with particular ones of said stored sets of features, where the particular ones of said stored sets of features are ones of said stored sets of features where the storage identification code matches the transmitter identification code, to determine confidence levels that said received set of features mismatches each of said particular ones of said stored sets of features, subscriber service means for controlling subscriber service based upon the confidence levels from said comparing means. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A transmitter identification method for identifying ones of a plurality of transmitters that may include authorized transmitters and unauthorized transmitters, each transmitter broadcasting a transmitter signal where the transmitter signal is formed by processing information and by manipulating a carrier with the processed information, the transmitter s signal including external signal traits resulting from said manipulation that are characteristic of said transmitter, said information containing a transmitter identification code, said method comprising:
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receiving said transmitter signal to provide a corresponding received signal including said signal traits, demodulating said received signal to recover the transmitter identification code, and characterizing said signal traits of said received signal to form a received set of features, storing stored sets of feature information for each transmitter, comparing said received set of features with one or more of said stored sets of feature information. - View Dependent Claims (21, 22, 23)
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24. A communication method having a subscriber service for a plurality of transmitters that may include authorized transmitters for authorized users and unauthorized transmitters for unauthorized users, each transmitter broadcasting a transmitter signal where the transmitter signal is formed by processing information and by manipulating a carrier with the processed information, the transmitter signal including external signal traits resulting from said manipulation that are characteristic of said transmitter, said information containing a transmitter identification code, said subscriber service controlling use of the system by users, said communication method comprising:
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transmitter identification steps including, receiving, for each transmitter, said transmitter signal to provide a corresponding received signal including said signal traits, demodulating, for each transmitter, said received signal to recover the transmitter identification code, characterizing, for each transmitter, said signal traits of said received signal to form a received set of features characterizing each said transmitter, storing stored sets of features in connection with storage identification codes such that for each storage identification code there may be zero or more first stored sets of features corresponding to an authorized transmitter and zero or more second stored sets of features corresponding to one or more unauthorized transmitters, comparing the received set of features with. particular ones of said stored sets of features, where the particular ones of said stored sets of features are ones of said stored sets of features where the storage identification code matches the transmitter identification code, to determine confidence levels that said received set of features mismatches each of said particular ones of said stored sets of features, subscriber service steps for controlling subscriber service based upon the confidence levels from said comparing step. - View Dependent Claims (25)
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Specification