RF broadcast system utilizing internal telephone lines

• US 5,929,896 A
• Filed: 06/21/1996
• Issued: 07/27/1999
• Est. Priority Date: 07/14/1989
• Status: Expired due to Fees

• Current Assignee: United Access Technologies LLC
• Original Assignee: Inline Connection Corporation
• Inventors: Domnitz, Robert H., Mahn, Terry G., Goodman, David D.
• Primary Examiner(s): Chan, Wing F.
• Application Number:
  US08/670,216
• Time in Patent Office: 1,131 Days
• Field of Search: 379/64, 379/65, 379/90, 379/101, 379/102, 379/104, 379/105, 379/96-98, 379/93, 379/90.01, 379/93.01, 379/93.05-93.09, 379/93.14, 379/93.15, 379/93.26 , 379/101.01, 379/102.01-102.03, 379/102.07, 348/14, 348/17-19, 348/734, 348/10, 359/142, 359/145-148, 455/402
• US Class Current: 348/14.12
• CPC Class Codes: H04B 2203/545 Audio/video application, e.g. interphone
• CPC Class Codes: H04L 12/2838 Distribution of signals within a home automation network, e.g. involving splitting/multiplexing signals to/from different paths adaptations of television systems for transmission by electric cable for domestic distribution H04N7/106; hybrid transport H04L12/6418; home network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04M 11/00 Telephonic communication systems specially adapted for combination with other electrical systems
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data
• CPC Class Codes: H04N 7/108 the cable being constituted by a pair of wires

Abstract

An audio/video transmission system for facilitating transmission of video, hi-fi audio, digital, and control signals (such as infrared remote control signals) between different locations in a residence using existing and active telephone wiring. Simultaneous transmission of signals of each type over active telephone lines is achieved without interference with telephone communications or with the other signal types. Transmission succeeds without requiring special treatment of the video signals beyond RF conversion, despite signal attenuation inherent in transmission over the telephone line media. The fidelity of audio reproduction at the receiving locations is sufficiently high to support the transmission of signals from digital devices without significant loss of audio quality. Multiple video sources and high fidelity audio sources may be tied into the system and selected as desired. Remote control signals generated in one room may be utilized to control video and audio sources in another room without requiring a clear line of sight between the remote control device and the receiver.

Claims

1. A signal transmission system comprising:

a twisted-pair telephone wiring network having a junction and at least three twisted-pair lines connected to one another at said junction, said network having a first port connected to a telephone exchange and a second port connected to a telephone device;

signal generating means for generating a first digital signal at a first location,

first converting means operatively connected to said signal generating means at said first location for converting said first digital signal to an analog signal having substantially the same information content as said first digital signal;

transmitting means operatively connected to said converting means and said wiring network for transmitting said analog signal onto said network;

receiving means operatively connected to said network for receiving said analog signal over said network at a second location substantially spaced from said first location;

second converting means operatively connected to said receiving means at said second location for converting said analog signal to a second digital signal having substantially the same information content as said first digital signal;

digital processing means operatively connected to said second converting means for operating on said second digital signal; and

at one of said first location and said second location, means for presenting a high impedance to signals whose energy is concentrated at frequencies below the highest frequency used for communication by ordinary telephone devices, while allowing said analog signal to transmit substantially unaltered.

2. The system defined in claim 1 wherein said means for converting including means to express said analog signal within in a selected frequency range, said selected frequency range exceeding the highest frequency used for communication by ordinary telephone devices.

3. The system defined in claim 2 wherein the information content of said first digital signal is embodied in the shifting between two discrete voltage levels, and said expressing means including means to respond to said shifting to accomplish one of:

(a) frequency modulation of an analog carrier signal by shifting the frequency of said carrier between two frequencies,

(b) creation of a time-varying analog signal that shifts regularly between two voltage levels, shifting from high to low in response to one of said two discrete voltage levels, and low to high in response to said other level, thereby creating a square wave with substantially all of its energy above the highest frequency used for communication by ordinary telephone devices.

4. The system defined in claim 1, further including means for impeding said analog signal from being coupled from said network to said telephone device.

5. The system defined in claim 1 wherein said transmitting means includes means for balancing said analog signal on said network wiring.

6. The system defined in claim 1, further comprising means connected to said network for reducing interference at said digital processing means owing to reflections of said analog signal in said network.

7. The system defined in claim 6 wherein one of said twisted-pair lines has an open termination, said means for reducing interference including means connected to said network at said open termination for matching impedance of said one of said twisted-pair lines at higher frequencies, thereby eliminating reflection of said analog signal at said open termination.

8. The system defined in claim 7, further comprising means at said open termination for inserting a connector of a high-frequency device and means for bypassing said means for matching impedance upon reception of said connector by said means for inserting.

9. The system defined in claim 7, wherein said means for converting includes said means to express said analog signal within in a selected frequency range, said selected frequency range exceeding the highest frequency used for communication by ordinary telephone devices.

10. The system defined in claim 9, further including means for impeding said analog signal from being coupled from said network to said telephone device.

11. The system defined in claim 2, further comprising a video source at said first location, and a video transmission system for transmitting video information from said source across said network to a video destination at said second location.

12. The system defined in claim 11, wherein said video transmission system further includes circuitry to receive said video information from said video source and to re-express said video information as a time-varying video signal substantially confined within a video frequency range that is different from and does not overlap said selected frequency band and the frequency band occupied by ordinary telephone signals, said receiving and re-expressing circuitry being located at said first location.

13. The system defined in claim 12, wherein said receiving and re-expressing circuitry receives said video information as a baseband video signal and re-expresses said video information in said video frequency range by frequency modulating a carrier with said baseband video signal.

14. The system defined in claim 9, further including:

alternative signal generating means and alternative converting means at said second location for converting an alternative digital signal to a alternative analog signal having substantially the same information content as said alternative digital signal,

alternative transmitting means operatively connected to said alternative converting means and said wiring network for transmitting said alternative analog signal onto said network at said second location;

alternative receiving means operatively connected to said network for receiving said alternative analog signal over said network at said first location;

second alternative converting means operatively connected to said alternative receiving means at said second location for converting said alternative analog signal to a alternative

second digital signal having substantially the same information content as said alternative digital signal, alternative digital processing means operatively connected to said second alternative converting means for operating on the information content of said alternative second digital signal.

15. The system defined in claim 9, further including:

a third location substantially spaced from said second and said first location, and receiving means operatively connected to said network for receiving said analog signal over said network at a said third location;

third converting means operatively connected to said receiving means at said third location for converting said analog signal to a second digital signal having substantially the same information content as said first digital signal;

second digital processing means operatively connected to said third converting means for operating on said second digital signal, said second digital processing means operating on said second digital signal independent of said first digital processing means.

16. The system defined in claim 2, further comprising a source of control signals at said second location, and a control signal transmission system for transmitting control signals from said source across said network to a control signal destination at said first location, wherein said source generates said control signal as time variations in characteristics of infrared light energy, said transmission system further includes light sensitive electronics to re-express said variations in light characteristics as an electrical signal, the energy of said electrical signal being substantially confined within a frequency range that is different from and does not overlap said selected frequency band and the frequency band occupied by ordinary telephone signals, said electrical signal transmitting across said network while confined within said frequency range.

33. The system defined in claim 1, wherein one of said first location and said second location includes a means for presenting a high impedance to signals whose energy is concentrated at frequencies above the highest frequency used for communication by ordinary telephone devices, while allowing signals below said highest frequency to transmit unaltered.

17. A signal transmission method comprising:

generating a first digital signal at a first location, and

converting said first digital signal to an analog signal having substantially the same information content as said first digital signal, and

transmitting said analog signal onto a twisted-pair telephone wiring network having a junction and at least three twisted-pair lines connected to one another at said junction, said network having a first port connected to a telephone exchange and a second port connected to a telephone device, and receiving said analog signal over said network at a second location substantially spaced from said first location, and converting said received analog signal to a second digital signal having substantially the same information content as said first digital signal, and

digital processing said second digital signal, and at one of said first location and said second location, presenting a high impedance to signals whose energy is concentrated at frequencies below the highest frequency used for communication by ordinary telephone devices, while allowing said analog signal to transmit substantially unaltered.

18. The method defined in claim 17 wherein said converting includes expressing said analog signal within in a selected frequency range, said selected frequency range exceeding the highest frequency used for communication by ordinary telephone devices.

19. The method defined in claim 18, further including the expression of the information content of said first digital signal in the shifting between two discrete voltage levels, said expression including the response to said shifting to accomplish one of:

(a) frequency modulation of an analog carrier signal by shifting the frequency of said carrier between two frequencies,

(b) creation of a time-varying analog signal that shifts regularly between two voltage levels, shifting from high to low in response to one of said two discrete voltage levels, and low to high in response to said other level, thereby creating a square wave with substantially all of its energy above the highest frequency used for communication by ordinary telephone devices.

20. The method defined in claim 17, further including the impeding of said analog signal from being coupled from said network to said telephone device.

21. The method defined in claim 17 wherein said transmitting further includes balancing said analog signal on said network wiring.

22. The method defined in claim 17, further including the reducing of interference owing to reflections of said analog signal in said network.

23. The method defined in claim 22, wherein said reducing further includes matching the impedance of said one of said twisted-pair lines at an open termination.

24. The method defined in claim 23, further including the insertion of a connector of a high-frequency device and the bypassing of said impedance matching in response to insertion of said connector.

25. The method defined in claim 23, wherein said converting includes expressing said analog signal within in a selected frequency range, said selected frequency range exceeding the highest frequency used for communication by ordinary telephone devices.

26. The method defined in claim 25, further including the impeding of said analog signal from being coupled from said network to said telephone device.

27. The method defined in claim 18, further comprising the transmitting of video information from a video source at said first location across said network to a video destination at said second location.

28. The method defined in claim 27, further including the expressing of said video information as a time-varying video signal substantially confined within a video frequency range that is different from and does not overlap said selected frequency band and the frequency band occupied by ordinary telephone signals.

29. The method defined in claim 28, wherein said expressing of said video information in said video frequency range is preceded by reception of said video information as a baseband video signal, and includes frequency modulating a carrier with said baseband video signal.

30. The method defined in claim 25, further including the reception of an alternative digital signal at said second location and the converting to a alternative analog signal having substantially the same information content as said

alternative digital signal, and

transmitting said alternative analog signal onto said wiring network at said second location, and

receiving said alternative analog signal over said network at said first location, and

converting said alternative analog signal to a alternative second digital signal having substantially the same information content as said alternative digital signal, and

digitally processing said alternative second digital signal.

31. The system defined in claim 25, further including:

receiving said analog signal from said network at a third location substantially spaced from said second and said first location, converting said analog signal to a second digital signal having substantially the same information content as said first digital signal.

32. The method defined in claim 18, further comprising a source of control signals at said second location, and a destination of control signals at said first location, and further including:

generation of said control signal as time variations in characteristics of infrared light energy, and

transmitting control signals from said source across said network to said destination at said first location, and re-expression of said variations in light characteristics as an electrical signal, the energy of said electrical signal being substantially confined within a frequency range that is different from and does not overlap said selected frequency band and the frequency band occupied by ordinary telephone signals, said electrical signal transmitting across said network while confined within said frequency range.

34. The method defined in claim 17, further comprising presenting a high impedance to signals whose energy is concentrated at frequencies above the highest frequency used for communication by ordinary telephone devices, while allowing signals below said highest frequency to transmit unaltered at one of said first location and said second location.

35. A signal transmission system comprising:

a twisted-pair telephone wiring network having a junction and at least three twisted-pair lines connected to one another at said junction, said network having a first port connected to a telephone exchange and a second port connected to a telephone device;

signal generating means for generating an analog signal at a first location,

transmitting means operatively connected to said signal generating means and said wiring network for transmitting said analog signal onto said network;

receiving means operatively connected to said network for receiving said analog signal over said network at a second location substantially spaced from said first location;

processing means operatively connected to said second location for operating on said analog signal; and

at one of said first location and said second location, means for presenting a high impedance to signals whose energy is concentrated at frequencies below the highest frequency used for communication by ordinary telephone devices, while allowing said analog signal to transmit substantially unaltered.

36. The system described in claim 35, wherein said analog signal is a video signal.

37. A signal transmission method comprising:

generating an analog signal at a first location, and

transmitting said analog signal onto a twisted-pair telephone wiring network having a junction and at least three twisted-pair lines connected to one another at said junction, said network having a first port connected to a telephone exchange and a second port connected to a telephone device, and receiving said analog signal over said network at a second location substantially spaced from said first location, and

processing said analog signal, and at one of said first location and said second location, presenting a high impedance to signals whose energy is concentrated at frequencies below the highest frequency used for communication by ordinary telephone devices, while allowing said analog signal to transmit substantially unaltered.

38. The method described in claim 37, wherein said analog signal is a video signal.