Method of, and apparatus for, protecting from radio frequency interference

• US 20070010206A1
• Filed: 03/16/2004
• Published: 01/11/2007
• Est. Priority Date: 03/27/2003
• Status: Active Grant

• Current Assignee: Uniloc 2017 LLC (SoftBank Group Corp.)
• Original Assignee: IPG Electronics 503 Limited (Coller IP Capital Limited)
• Inventors: Caldwell, Richard, Payne, Adrian
• Granted Patent: US 7,650,115 B2
• Time in Patent Office: Days
• US Class Current: 455/64
• CPC Class Codes: H04W 48/02 Access restriction performed under specific conditions

Abstract

A method of protecting an apparatus from radio frequency interference, comprises a policing terminal (PT) detecting the presence of an interfering radio terminal (16) in the protected environment and actively rendering ineffective or terminating transmissions by the interfering radio terminal. Various options can be followed by the policing terminal (PT) including (a) attempting to become the master station of a network of which the interfering terminal is a member and instructing the members to close down or (b) failing to become the master station and transmitting interference signals for at least a selected portion, for example preamble and sync, of the duration of a data packet transmitted by the interfering station.

Claims

1. A method of protecting an apparatus (18 or 10) from radio frequency interference in a predetermined radio frequency band, comprising,

at a policing terminal (PT),

detecting the presence of a radio terminal (16) operable to generate interference in the predetermined radio frequency band in accordance with a first predetermined signalling protocol, and

transmitting a first signal matched to a characteristic of the first predetermined signalling protocol,

wherein, in response to receiving the first signal, the radio terminal (16) is inhibited as a source of interference.

2. A method as claimed in claim 1, wherein detecting the presence of the radio terminal (16) comprises detecting a second signal transmitted by the radio terminal in accordance with the first predetermined signalling protocol.

3. A method as claimed in claim 2, wherein transmission of the second signal is responsive to a third signal transmitted by the policing terminal (PT).

4. A method as claimed in claim 1, wherein the first signal matched to a characteristic of the first predetermined signalling protocol comprises a message selected from the first predetermined signalling protocol.

5. A method as claimed in claim 4, wherein the message is a command to disconnect from a communication.

6. A method as claimed in claim 1, wherein the matching of the first signal to a characteristic of the first predetermined signalling protocol comprises timing the transmission of the first signal to interfere with at least a portion of a transmission made by the radio terminal (16) in accordance with the first predetermined signalling protocol.

7. A method as claimed in claim 6, wherein the portion is at least one of a preamble, synchronisation word, address field or header field.

8. A method as claimed in claim 4, wherein the first predetermined signalling protocol is a networking protocol, the policing terminal (PT) is equipped to operate in accordance with the first predetermined signalling protocol, and the policing terminal (PT) joins a network comprising the radio terminal (16) prior to transmitting the message.

9. A method as claimed in claim 8, wherein the policing terminal (PT) becomes a master station in the network prior to transmitting the message.

10. A method as claimed in claim 2, wherein detecting the presence of the radio terminal (16) comprises detecting from the second signal the address of the radio terminal.

11. A method as claimed in claim 2, wherein detecting the presence of the radio terminal (16) comprises determining a frequency hop sequence in use by the radio terminal (16).

12. A method as claimed in claim 6, wherein the first signal is modulated with noise.

13. A method as claimed in claim 1, wherein the policing terminal (PT) is a component of the apparatus being protected

14. A method as claimed in claim 1, wherein the apparatus (10) is equipped to operate in accordance with a second predetermined signalling protocol.

15. A policing terminal (PT) for protecting an apparatus from radio frequency interference in a predetermined radio frequency band, comprising

means (24, 28, M3) for detecting the presence of a radio terminal (16) operable to generate interference in the predetermined radio frequency band in accordance with a first predetermined signalling protocol, and

means (26, 28, M3) for transmitting a first signal matched to a characteristic of the first predetermined signalling protocol to inhibit the radio terminal (16) as a source of interference.

16. A policing terminal as claimed in claim 15, wherein the means (24, 28, M3) for detecting the presence of the radio terminal (16) is adapted to detect a second signal transmitted by the radio terminal (16) in accordance with the first predetermined signalling protocol.

17. A policing terminal as claimed in claim 16, comprising means (26, 28, M3) for transmitting a third signal for eliciting transmission of the second signal.

18. A policing terminal as claimed in claim 15, wherein the means (26, 28, M3) for transmitting the first signal matched to a characteristic of the first predetermined signalling protocol is adapted to transmit a message selected from the first predetermined signalling protocol.

19. A policing terminal as claimed in claim 18, wherein the message is a command to disconnect from a communication.

20. A policing terminal as claimed in claim 15, wherein the means (26, 28, M3) for transmitting the first signal matched to a characteristic of the first predetermined signalling protocol is adapted to transmit the first signal concurrently with at least a portion of a transmission made by the radio terminal (16) in accordance with the first predetermined signalling protocol.

22. A policing terminal as claimed in claim 18, wherein the first predetermined signalling protocol is a networking protocol, the policing terminal (PT) comprises means (28, M3) for operating in accordance with the first predetermined signalling protocol, and the means (28, M3) for operating is adapted to join a network comprising the radio terminal (16) prior to transmission of the message.

23. A policing terminal as claimed in claim 22, wherein the means (28, M3) for operating in accordance with the first predetermined signalling protocol is adapted to become a master station in the network prior to transmission of the message.

24. A policing terminal as claimed in claim 16, wherein means (24, 28, M3) for detecting the presence of the radio terminal (16) is adapted to determine from the second signal the address of the radio terminal (16).

25. A policing terminal as claimed in claim 16, wherein the means (24, 28, M3) for detecting the presence of the radio terminal (16) is adapted to determine a frequency hop sequence in use by the radio terminal (16).

26. A policing terminal as claimed in claim 20, wherein means (26, 28, M3) for transmitting the first signal is adapted to modulate the first signal with noise.

27. An electronic apparatus comprising the policing terminal (PT) as claimed in claim 15.

28. A wireless network operable in accordance with the second signalling protocol and comprising a policing terminal (PT) as claimed in claim 15.

21. A policing terminal as claimed in claim 21, wherein the portion is at least one of a preamble, synchronisation word, address field or header field.