System and method for collection of transmission characteristics

• US 5,893,031 A
• Filed: 06/27/1996
• Issued: 04/06/1999
• Est. Priority Date: 06/27/1996
• Status: Expired due to Fees

• Current Assignee: Cellular Technical Services Co., Inc. (Asensus Surgical, Inc.)
• Original Assignee: Cellular Technical Services Co., Inc. (Asensus Surgical, Inc.)
• Inventors: Stanhope, David M., Hoogerwerf, David N.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Raju, Seid
• Application Number:
  US08/670,512
• Time in Patent Office: 1,013 Days
• Field of Search: 455/410, 455/411, 455/425, 455/115, 455/575, 455/90, 455/572, 455/67.2, 375/200
• US Class Current: 455/410
• CPC Class Codes: H04B 17/16 Test equipment located at the transmitter
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/79 Radio fingerprint
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

A system and method for collecting fingerprint reference wave forms under controlled conditions includes a radio frequency (RF) enclosure designed to receive a cellular telephone. A control system, including a transmitter and receiver provides RF communications with a cellular phone placed in the enclosure. A processor controls operation of the transmitter and receiver. The processor sends commands to the cellular phone in the enclosure using the transmitter. The transmitted commands are selected to elicit a RF transmission from the cellular phone in response to the command. The receiver detects the response from the cellular telephone and generates a reference wave form indicative of the transmission characteristics of the transmitter of the cellular phone in the enclosure. The processor captures one or more reference waveforms that can be used to generate a fingerprint indicative of a transmission characteristic of the transmitter of the cellular telephone. In addition, the system can include an external power supply and temperature control system to vary the voltage level of power supplied to the cellular telephone in the enclosure and to vary the temperature in the enclosure. By varying the operating voltage and temperature, the processor can collect reference waveforms under a variety of operating conditions. In addition, the processor can select the carrier frequency for the cellular telephone and for the transmitter and receiver of the control system. Furthermore, the processor can vary the transmit power of the system transmitter and the transmit power of the transmitter within the cellular telephone itself. The system is sized to be readily moved from one location to another to permit the simple collection of reference waveforms under a variety of controlled conditions.

Claims

1. A system for the collection of transmission characteristics for authentication of a cellular telephone transmitter of a cellular telephone, the system comprising:

an enclosure sized to accept the cellular telephone;

a transmitter capable of operating at frequencies used for cellular telephone communication;

a receiver capable of operating at frequencies used for cellular telephone communication, said receiver receiving signals from the cellular telephone when in said enclosure and generating receiver output signals representative of said received signals;

an antenna coupled to said transmitter and said receiver and extending into said enclosure, said antenna coupling radio frequencies transmitted by said transmitter to said enclosure and receiving radio frequencies emanating from the cellular telephone when in said enclosure, said antenna coupling said received radio frequencies to said receiver; and

a processor to control said transmitter and cause said transmitter to transmit signals to said enclosure to elicit a transmission response signal from the cellular telephone when in said enclosure, said processor receiving from said receiver output signals indicative of a transmission characteristic of the cellular telephone when in said enclosure and responding to said transmit signals from said transmitter.

2. The system of claim 1 wherein said enclosure is substantially impenetrable to radio frequency signals.

3. The system of claim 1 wherein said processor selectively controls operational parameters of said transmitter to control said transmit signals during transmission to the cellular telephone in said enclosure and selectively controls said receiver when receiving said signals from the cellular telephone.

4. The system of claim 3 wherein said operational parameters comprise a selected carrier frequency for said transmitter and said receiver, said transmitter using said selected carrier frequency during transmission to the cellular telephone in said enclosure and said receiver using said selected carrier frequency when receiving said signals from the cellular telephone.

5. The system of claim 3 wherein said operational parameters comprise a selected transmission power level for said transmitter, said transmitter using said selected transmission power level during transmission to the cellular telephone in said enclosure.

6. The system of claim 1 wherein the cellular telephone has a selectable transmission power level and said transmitted signals to the cellular telephone when in said enclosure include signals to select a particular power level for said transmission power level, said processor receiving said receiver output signals indicative of said transmission characteristic as a function of said transmission power level.

7. The system of claim 1 wherein said processor processes said receiver output signals indicative of said transmission characteristic of the cellular telephone when in said enclosure to generate a fingerprint associated with said transmission characteristic.

8. The system of claim 7 wherein said processor stores said fingerprint for subsequent use in the authentication of the cellular telephone when used outside of said enclosure.

9. The system of claim 1, further including a computer system coupled to said processor and receiving said receiver output signals from said processor, said computer system processing said receiver output signals indicative of said transmission characteristic of the cellular telephone when in said enclosure to generate a fingerprint associated with said transmission characteristic.

10. The system of claim 9, further including a network connection, said processor being coupled to said computer system by said network connection.

11. The system of claim 9 wherein said computer system stores said fingerprint for subsequent use in the authentication of the cellular telephone when used outside of said enclosure.

12. The system of claim 1, further including a temperature control system to provide a selected temperature within said enclosure, said transmitter eliciting said transmission response from the cellular telephone at said selected temperature and said receiver receiving said signals from the cellular telephone at said selected temperature.

13. The system of claim 12 wherein said temperature control system is coupled to and controlled by said processor, said processor controlling the temperature in said enclosure by controlling said temperature controller.

14. The system of claim 12 wherein said temperature control system selectively varies said selected temperature, said processor receiving said receiver output signals indicative of said transmission characteristic as a function of temperature.

15. The system of claim 1 for use with the cellular connectable to an external power supply, the system further including:

a power supply to provide a selected level of electrical power to the cellular telephone when in said enclosure; and

a power connector, coupled to said power supply and connectable to the cellular telephone when in said enclosure, to provide power to the cellular telephone when in said enclosure.

16. The system of claim 15 wherein said power supply is coupled to and controlled by said processor, said processor controlling said selected level of electrical power provided to the cellular telephone in said enclosure by controlling said power supply.

17. The system of claim 16 wherein said power supply selectively varies said selected level of electrical power to the cellular telephone when in said enclosure, said processor receiving said receiver output signals indicative of said transmission characteristic as a function of said selected level of electrical power.

18. The system of claim 1 for use with the cellular telephone having a selectable operating frequency, wherein said transmit signals eliciting said transmission response signal is a command to the cellular telephone to select the operating frequency.

19. The system of claim 1 for use with the cellular telephone having a selectable transmit power level wherein transmit signals eliciting said transmission response signal is a command to the cellular telephone to select the transmit power level.

20. The system of claim 1 wherein the cellular telephone has a keypad operable by the user of the cellular telephone when used outside of said enclosure and a keypad connector for remote operation of the keypad, the system further including a cellular telephone adapter coupled to said processor and capable of electrical connection to the keypad connector of the cellular telephone when inside said enclosure, said processor generating keypad commands for simulated user operation of the cellular telephone when in said enclosure, said processor providing said keypad commands to the keypad using said cellular telephone adapter.

21. A system for the collection of transmission characteristics for authentication of a cellular telephone transmitter of a cellular telephone having a keypad operable by the user of the cellular telephone and a keypad connector for remote operation of the keypad, the system comprising:

an enclosure sized to accept the cellular telephone;

a receiver capable of operating at frequencies used for cellular telephone communication, said receiver receiving signals from the cellular telephone when in said enclosure and generating receiver output signals representative of said received signals;

an antenna coupled to said receiver and extending into said enclosure, said antenna receiving radio frequencies emanating from the cellular telephone when in said enclosure and coupling said received radio frequencies to said receiver;

a cellular telephone adapter capable of electrical connection to the keypad connector of the cellular telephone when inside said enclosure; and

a processor generating keypad commands for simulated user operation of the cellular telephone when in said enclosure, said processor providing said keypad commands to the keypad using said cellular telephone adapter to elicit a transmission response signal from the cellular telephone when in said enclosure, said processor receiving from said receiver output signals indicative of a transmission characteristic of the cellular telephone when in said enclosure and responding to said keypad commands from said processor.

22. The system of claim 21 wherein said enclosure is substantially impenetrable to radio frequency signals.

23. The system of claim 21 wherein said processor processes said receiver output signals indicative of said transmission characteristic of the cellular telephone when in said enclosure to generate a fingerprint associated with said transmission characteristic.

24. The system of claim 23 wherein said processor stores said fingerprint for subsequent use in the authentication of the cellular telephone when used outside of said enclosure.

25. The system of claim 21, further including a computer system coupled to said processor and receiving said receiver output signals from said processor, said computer system processing said receiver output signals indicative of said transmission characteristic of the cellular telephone when in said enclosure to generate a fingerprint associated with said transmission characteristic.

26. The system of claim 21, further including a temperature control system to provide a selected temperature within said enclosure, said processor eliciting said transmission response from the cellular telephone at said selected temperature and said receiver receiving said signals from the cellular telephone at said selected temperature.

27. The system of claim 26 wherein said temperature control system is coupled to and controlled by said processor, said processor controlling the temperature in said enclosure by controlling said temperature controller.

28. The system of claim 21 for use with the cellular connectable to an external power supply, the system further including:

a power supply to provide a selected level of electrical power to the cellular telephone when in said enclosure; and

a power connector, coupled to said power supply and connectable to the cellular telephone when in said enclosure, to provide power to the cellular telephone when in said enclosure.

29. The system of claim 28 wherein said power supply is coupled to and controlled by said processor, said processor controlling said selected level of electrical power provided to the cellular telephone in said enclosure by controlling said power supply.

30. The system of claim 21, further including a transmitter capable of operating at frequencies used for cellular telephone communication, said transmitter coupled to said antenna to transmit to the cellular telephone in said enclosure and coupled to said processor, said processor controlling said transmitter and causing said transmitter to transmit signals to said enclosure to elicit said transmission response signal from the cellular telephone when in said enclosure, said processor receiving from said receiver output signals indicative of a transmission characteristic of the cellular telephone when in said enclosure and responding to said transmit signals from said transmitter.

31. A method for the collection of transmission characteristics for authentication of a cellular telephone transmitter of a cellular telephone wherein the cellular telephone has a keypad operable by the user of the cellular telephone and a keypad connector for remote operation of the keypad, the method comprising:

placing the cellular telephone in an enclosure sized to accept the cellular telephone;

coupling a cellular telephone adapter to the keypad connector of the cellular telephone when inside said enclosure;

generating keypad commands for simulated user operation of the cellular telephone when in said enclosure;

eliciting a transmission response signal from the cellular telephone by providing said keypad commands to the keypad using said cellular telephone adapter, wherein said step of eliciting said transmission response signal is performed by said keypad commands;

receiving said transmission response signal from the cellular telephone when in said enclosure and generating receiver output signals representative of said received transmission response signal; and

determining from said receiver output signals a transmission characteristic of the cellular telephone when in said enclosure and responding to said step of eliciting said transmission response signal.

32. The method of claim 31 wherein said step of receiving said transmission response signal from the cellular telephone when in said enclosure uses a receiver capable of operating at frequencies used for cellular telephone communication, said receiver receiving signals from the cellular telephone when in said enclosure and generating said receiver output signals representative of said received signals.

33. The method of claim 31 wherein said enclosure is substantially impenetrable to radio frequency signals.

34. The method of claim 31, further including the step of processing said receiver output signals indicative of said transmission characteristic of the cellular telephone when in said enclosure to generate a fingerprint associated with said transmission characteristic.

35. The method of claim 34, further including the step of storing said fingerprint for subsequent use in the authentication of the cellular telephone when used outside of said enclosure.

36. The method of claim 31, further including the step of providing a selected temperature within said enclosure, said step of eliciting said transmission response eliciting said transmission response from the cellular telephone at said selected temperature and said step of receiving said signals from the cellular telephone receiving said signals from the cellular telephone at said selected temperature.

37. The method of claim 36, further including the steps of selectively varying said selected temperature, said step of determining said transmission characteristic of the cellular telephone deter-mining said transmission characteristic as a function of temperature.

38. The method of claim 31 for use with the cellular connectable to an external power supply, the method further including the step of connecting a power supply to the cellular telephone when in said enclosure to provide a selected level of electrical power to the cellular telephone.

39. The method of claim 38, further including the steps of selectively varying said selected level of electrical power, said step of determining said transmission characteristic of the cellular telephone determining said transmission characteristic as a function of electrical power.