Active waveform collection for use in transmitter identification
First Claim
1. A method of collecting a reference waveform of a wireless telephone comprising the steps of:
- (a) polling a selected one of a plurality of wireless telephones to automatically stimulate a transmission response signal containing a reference waveform indicative of a transmission characteristic of the selected wireless telephone;
(b) receiving from the selected wireless telephone the transmission response signal responsive to the poll;
(c) extracting the reference waveform from the received transmission response signal; and
(d) storing the extracted reference waveform.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and system for actively and rapidly collecting reference waveforms from a large number of cellular telephones is provided. The reference waveforms are used to generate fingerprints which are used to distinguish between authorized cellular telephones and unauthorized cellular telephones. Initially, the system selects a cellular telephone whose reference waveform is desired. The selected cellular telephone is then sent a polling message such as a page or registration request. The cellular telephone receives the polling message and transmits a radio frequency (RF) signal containing a reference waveform that contains certain transmission characteristics unique to the selected cellular telephone. From the received RF signal, the reference waveform is extracted and stored. Preferably, the selected cellular telephone is polled repeatedly in order to receive a sufficiently large number of reference waveforms to be able to generate an accurate fingerprint. One method of polling the cellular telephone is by calling the selected cellular telephone through a cellular telephone system. Another method of polling the cellular telephone is by transmitting a control message such as a page, registration, audit or maintenance message.
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Citations
43 Claims
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1. A method of collecting a reference waveform of a wireless telephone comprising the steps of:
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(a) polling a selected one of a plurality of wireless telephones to automatically stimulate a transmission response signal containing a reference waveform indicative of a transmission characteristic of the selected wireless telephone; (b) receiving from the selected wireless telephone the transmission response signal responsive to the poll; (c) extracting the reference waveform from the received transmission response signal; and (d) storing the extracted reference waveform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 15)
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11. A method of collecting a reference waveform of a wireless telephone comprising the steps of:
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polling the wireless telephone to automatically stimulate a transmission response signal containing a reference waveform indicative of a transmission characteristic of the wireless telephone; receiving from the wireless telephone the transmission response signal responsive to the poll; extracting the reference waveform from the received transmission response signal; storing the extracted reference waveform; validating the reference waveform when only one transmission response signal is received; and discarding the reference waveform when more than one transmission response signals responsive to the poll are received.
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12. A method of collecting a reference waveform of a wireless telephone comprising the steps of:
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polling the wireless telephone to automatically stimulate a transmission response signal containing a reference waveform indicative of a transmission characteristic of the wireless telephone; receiving from the wireless telephone the transmission response signal responsive to the poll; extracting the reference waveform from the received transmission response signal;
p1 storing the extracted reference waveform;selecting a wireless telephone among a plurality of wireless telephones currently transmitting on a call; and waiting until the selected wireless telephone hangs up before polling the selected wireless telephone to automatically stimulate a transmission response signal therefrom. - View Dependent Claims (13)
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16. A method of collecting a plurality of reference waveforms of an authorized wireless telephone to be later used in distinguishing telephone calls made by the authorized wireless telephone from telephone calls made by an unauthorized wireless telephone, the method comprising the steps of:
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selecting the authorized wireless telephone among a plurality of wireless telephones currently transmitting on a call; and repeating the following steps n times where n is greater than 1; polling the selected wireless telephone to automatically stimulate a transmission response signal therefrom; receiving from the selected wireless telephone the transmission response signal responsive to the poll; extracting a reference waveform contained in the transmission response signal, the reference waveform indicating a transmission characteristic of the wireless telephone; and storing the reference waveform. - View Dependent Claims (17, 18)
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19. A method of collecting a reference waveform of an authorized wireless telephone to be later used in distinguishing telephone calls made by the authorized wireless telephone from telephone calls made by an unauthorized wireless telephone, the method comprising the steps of:
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(a) transmitting data to the authorized wireless telephone to elicit a transmission response signal from the authorized wireless telephone, the transmission response signal containing a reference waveform indicative of a transmission characteristic of the authorized wireless telephone; (b) receiving from the authorized wireless telephone the transmission response signal responsive to the elicitation; (c) extracting the reference waveform from the received transmission response signal; and (d) storing the extracted reference waveform. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26)
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27. A method of using an existing wireless telephone system to collect a reference waveform of an authorized wireless telephone to be later used in distinguishing telephone calls made by the authorized wireless telephone and telephone calls made by an unauthorized wireless telephone over the existing wireless telephone system, the method comprising the steps of:
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(a) causing the existing wireless telephone system to transmit data to the authorized wireless telephone to elicit an automatic transmission response signal from the authorized wireless telephone, the transmission response signal containing a reference waveform indicative of a transmission characteristic of the authorized wireless telephone; (b) receiving from the authorized wireless telephone the transmission response signal responsive to the elicitation through the existing wireless telephone system; (c) extracting the reference waveform from the received transmission response signal; and (d) storing the extracted reference waveform. - View Dependent Claims (28, 29, 30, 31, 32)
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33. A system for collecting a reference waveform of an authorized wireless telephone to be later used in distinguishing telephone calls made by the authorized wireless telephone from telephone calls made by an unauthorized wireless telephone, the system comprising the steps of:
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a radio frequency (RF) transmitter operable to transmit an RF signal containing a polling message only to the authorized wireless telephone; a radio frequency (RF) receiver operable to receive from the authorized wireless telephone an automatic transmission response signal responsive to the polling message, the transmission response signal containing a reference waveform indicative of a transmission characteristic of the authorized wireless telephone; a processor connected to the RF transmitter and receiver, the processor being operable to cause the RF transmitter to transmit the polling message to the authorized wireless telephone and to extract a reference waveform from the transmission response signal received by the RF receiver; and a memory connected to the processor for storing the extracted reference waveform. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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Specification