Interoffice broadband communication system using twisted pair telephone wires

• US 6,346,964 B1
• Filed: 12/31/1996
• Issued: 02/12/2002
• Est. Priority Date: 12/31/1996
• Status: Expired due to Fees

• Current Assignee: VidSys Incorporated
• Original Assignee: Video Network Communications, Inc.
• Inventors: Rogers, Steven, Koenig, Ed, Hoppes, Brian
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Eng, George
• Application Number:
  US08/777,881
• Time in Patent Office: 1,869 Days
• Field of Search: 348/14-17, 348/6-8, 379/90.01, 379/93.01, 379/93.14, 379/93.17, 379/93.21, 379/202, 379/100.12, 370/260, 370/265, 370/430, 370/401, 709/204
• US Class Current: 348/14.11
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04M 3/567 Multimedia conference systems
• CPC Class Codes: H04N 7/108 the cable being constituted by a pair of wires
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN
• CPC Class Codes: H04Q 3/625 Arrangements in the private branch exchange

Abstract

A system including a broadband switch includes a controller which coordinates video call set-up and a switch for connecting various phone lines together through diplexers. The system permits video telephone conferencing and other video related applications to be performed over ordinary telephone wires. Two diplexer/modems are typically provided for each user: one at the user'"'"'s telephone jack and another at the central PBX location for that user'"'"'s telephone line. The PBX connections can usually be made in a central wiring closet. A video server can also be provided which retrieves video images from disk to provide on demand to users. the existing PBX handles the switching of normal telephone audio signals, and a broadband data switch handles the switching of broadband signals over the same telephone wires that the PBX uses. The broadband switch essentially “piggybacks” off the PBX system and avoids interference with telephone signals through the use of diplexers.

Claims

1. A system for providing video services over twisted pair telephone lines comprising:

a first plurality of video interface units each comprising a telephone port adapted to be coupled to a telephone, a video output port, and a telephone line port adapted to be coupled to twisted pair telephone line, wherein each of the first plurality of video interface units passes ordinary telephone signals between its telephone port and its telephone line port, and demodulates modulated video data present at its telephone line port and provides the demodulated video data to its video output port;

a second plurality of video interface units each comprising a telephone line port adapted to be coupled to one of the first plurality of video interface units through twisted pair telephone line, a telephone switch port adapted to be coupled to a telephone switching unit which connects telephone lines, and a video input port for receiving a video signal, wherein each of the second plurality of video interface units passes ordinary telephone signals between its telephone switch port and its telephone line port and modulates video data present at its video input port and provides the modulated video data to its telephone line port without interfering with ordinary telephone signals; and

a computer controlled switch coupled between one of the second plurality of video interface units and a first video signal source and which in response to receiving a video connection request from one of the first plurality of video interface units over a corresponding telephone line causes a first video signal to be switched to the video input port of one of the second plurality of video interface units and thereafter to be transmitted in modulated form over the corresponding telephone line.

2. The system of claim 1,

wherein each of the first plurality of video interface units further comprises a video input port, wherein each of the first plurality of video interface units modulates video data present at its video input port and provides the modulated video data to its telephone line port without interfering with ordinary telephone signals; and

wherein each of the second plurality of video interface units further comprises a video output port, wherein each of the second plurality of video interface units demodulates modulated video data present at its telephone line port and provides the demodulated video signal to its video output port.

3. The system of claim 2, further comprising:

a video camera coupled to the video input port of one of the first plurality of video interface units to transmit full-motion color video data; and

a computer display device coupled to the video output port of the one video interface unit to display full-motion color video data received over the twisted pair telephone lines.

4. The system of claim 3,

wherein each of the first plurality of video interface units frequency modulates video data present at its video input port to a first frequency band;

and

wherein each of the second plurality of video interface units frequency modulates video data present at its video input port to a second frequency band different from the first frequency band.

5. The system of claim 1, wherein the computer controlled switch connects a video output port from another of the second plurality of video interface units to the video input port of the one video interface unit in response to receiving the video connection request from a user making a videoconference call.

6. The system of claim 1,

wherein each of the second plurality of video interface units modulates stereo audio data onto its telephone line port into a frequency band separate from the modulated video data;

and

wherein each of the first plurality of video interface units demodulates modulated stereo audio data present at its telephone line port and provides the demodulated audio data to an audio output port.

7. The system of claim 1,

further comprising a conference bridge which mixes three or more video signals into a mixed video signal;

wherein the computer controlled switch causes the mixed video signal to be switched to the video input port of one of the second plurality of video interface units.

8. The system of claim 7, wherein the conference bridge provides a plurality of viewing modes each of which causes a different display representation for a video conference call.

9. The system of claim 1, wherein the first video signal source comprises a TV tuner.

10. The system of claim 1, wherein the first video signal source comprises a video server.

11. The system of claim 1, further comprising a crosspoint video switch which connects two of the second plurality of video interface units.

12. A broadband switching system, comprising:

a first plurality of twisted pair telephone wires, each pair associated with one of a plurality of voice grade telephones;

a first plurality of signal modems each coupled between one of the plurality of voice grade telephones and a corresponding one of the first plurality of twisted pair telephone wires, wherein each of the first plurality of signal modems modulates and demodulates broadband signals on the corresponding one of the first plurality of twisted pair telephone wires in frequency bands outside the normal voice telephone range;

a second plurality of twisted pair telephone wires, each pair terminating at a voice grade telephone switch which connects two or more of the second plurality of twisted pair telephone wires in response to users making telephone calls from one of the plurality of voice grade telephones;

a second plurality of signal modems each coupled between one of the first plurality of twisted pair telephone wires and the telephone switch through one of the second plurality of twisted pair telephone wires, wherein each of the second plurality of signal modems modulates and demodulates broadband signals on a corresponding one of the first plurality of twisted pair telephone wires in frequency bands outside the normal voice telephone range; and

a broadband data switch coupled between the second signal modems and a broadband signal source and which in response to receiving a broadband connection request over one of the first plurality of twisted pair telephone wires connects a broadband signal having a frequency bandwidth greater than that normally provided to the plurality of voice grade telephones to one of the second plurality of signal modems and thereafter causes the broadband signal to be transmitted over one of the first plurality of twisted pair telephone wires.

13. The system of claim 12, wherein the broadband data switch switches a first broadband signal output from one of the second plurality of signal modems to another of the second plurality of signal modems.

14. The system of claim 13, wherein the first broadband signal comprises a full-motion color video signal.

15. The system of claim 14, wherein the first broadband signal further comprises a stereo audio signal corresponding to the full-motion color video signal.

16. The system of claim 15, wherein the first broadband signal further comprises a message data signal.

17. A method of providing broadband data service over unshielded twisted pair (UTP) telephone wires, comprising the steps of:

(1) providing a first plurality of broadband signal modems each of which connects between a telephone and UTP telephone wires, and which modulates and demodulates broadband data signals over the UTP telephone wires without interfering with telephone signals on such wires;

(2) providing a second plurality of broadband signal modems each of which connects between an existing telephone switch and one of the first plurality of broadband signal modems, and which modulates and demodulates broadband data signals over the UTP telephone wires;

(3) providing a broadband data switch coupled between two or more of the second plurality of broadband signal modems; and

(4) controlling the broadband data switch to selectively couple two or more of the second plurality of broadband signal modems in such a manner that a broadband signal communication path is established between at least two of the first plurality of signal modems over the UTP telephone wires.

18. The method of claim 17, wherein step (4) comprises the step of controlling the broadband data switch to establish a bidirectional video communication path between two of the first plurality of broadband signal modems.

19. The method of claim 17, wherein step (4) comprises the step of mixing broadband signals from two or more sources.

20. The method of claim 19, wherein step (4) comprises the step of mixing video signals from two users each associated with one of the telephones.

21. The method of claim 18, wherein step (4) comprises the step of receiving a video connection request through a data channel on the ordinary twisted pair telephone wires and, in response thereto, switching a first video signal received from one of the first plurality of signal modems to another of the first plurality of signal modems.

22. A broadband data switch for use in a system which includes a telephone switch, the broadband data switch comprising:

a first signal modem which connects to the telephone switch and to a first telephone line over which telephone calls are transmitted, wherein the first signal modem passes telephone call signals between the telephone switch and the first telephone line, and wherein the first signal modem demodulates a first modulated broadband signal present on the first telephone line and generates as an output a demodulated version of the first modulated broadband signal;

a second signal modem which connects to the telephone switch and to a second telephone line over which telephone calls are transmitted, wherein the second signal modem passes telephone call signals between the telephone switch and the second telephone line, and wherein the second signal modem receives as an input a first broadband input signal, modulates the first broadband input signal and injects a modulated version of the first broadband input signal onto the second telephone line in a frequency location which does not interfere with the telephone call signals; and

a computer controlled switch coupled between the first signal modem and the second signal modem which, in response to receiving a broadband connection request, couples the output of the first signal modem to the input of the second signal modem, such that broadband communication between the first and second telephone lines is effected.

23. The broadband data switch of claim 22, wherein the first modulated broadband signal comprises a frequency modulated color video signal, and wherein the demodulated version of the first modulated broadband signal comprises a baseband color video signal.

24. The broadband data switch of claim 23, wherein the computer controlled switch receives the broadband connection request from a data channel present on the first telephone line.

25. The broadband data switch of claim 23,

wherein the first signal modem further demodulates a first modulated audio signal present on the first telephone line and generates as an output a demodulated version of the first modulated audio signal;

wherein the second signal modem further receives as an input a first audio signal, modulates the first audio signal and injects a modulated version of the first audio signal onto the second telephone line; and

wherein the computer controlled switch couples the demodulated version of the first modulated audio signal to the first audio signal input to the second signal modem, such that audio communication between the first and second telephone lines is effected.

26. The broadband data switch of claim 22, wherein the computer controlled switch comprises a crosspoint matrix.

27. The broadband data switch of claim 22, further comprising an external output circuit, wherein the computer controlled switch couples the demodulated version of the first modulated broadband signal output from the first signal modem to the external output circuit.

28. The broadband data switch of claim 22,

wherein the first signal modem receives a second broadband input signal, modulates the second broadband input signal, and injects a modulated version of the second broadband input signal onto the first telephone line in a frequency location which does not interfere with the telephone call signals and does not interfere with the first modulated broadband signal present on the first telephone line;

wherein the second signal modem demodulates a second modulated broadband signal present on the second telephone line and generates a demodulated version of the second modulated broadband signal; and

wherein the computer controlled switch couples the demodulated version of the second modulated broadband signal to the second broadband input signal of the first signal modem, such that two-way broadband communication between the first and second telephone lines is effected.

29. The broadband data switch of claim 28, further comprising a mixing circuit which mixes the demodulated version of the first modulated broadband signal with the demodulated version of the second modulated broadband signal and provides a mixed output;

and

wherein the mixed output is provided as the first broadband input signal to the second signal modem.

30. A broadband data switch for use in a system which includes a telephone switch, the broadband data switch comprising:

a plurality of signal modulators each of which connects to the telephone switch and to a respective telephone line over which telephone calls are transmitted, wherein each signal modulator passes telephone call signals between the telephone switch and one of the respective telephone lines, and wherein each signal modulator modulates a broadband data signal present at an input thereof and injects the modulated broadband data signal onto a respective telephone line in a frequency location which does not interfere with the telephone call signals;

a broadband data circuit which provides a broadband data signal; and

a controller coupled between the plurality of signal modulators and the broadband data circuit which, in response to receiving a broadband connection request, couples the broadband data circuit to a selected one of the plurality of signal modulators, such that the broadband data signal is selectively coupled to the selected one signal modulator and is thereafter transmitted over a respective one of the telephone lines.

31. The broadband data switch of claim 30, wherein the controller couples the broadband data circuit to the selected one signal modulator through a crosspoint matrix.

32. The broadband data switch of claim 31, wherein the controller couples the broadband data circuit to more than one of the plurality of signal modulators, such that the same broadband signal is provided to multiple signal modulators.

33. The broadband data switch of claim 30, wherein the broadband data circuit comprises a television tuner circuit which demodulates a television signal and provides a demodulated television signal output.

34. The broadband data switch of claim 30, wherein the broadband data circuit comprises an H.320 compatible coder/decoder which provides an H.320 compatible signal from an external signal line.

35. The broadband data switch of claim 30, wherein the broadband data circuit comprises a conference bridge which mixes a plurality of signal inputs into a single broadband output signal.

36. The broadband data switch of claim 30, wherein the broadband data signal comprises a color video signal, and wherein each signal modulator frequency modulates the color video signal.

37. A system comprising the broadband data switch of claim 30 and a video server coupled to the broadband data switch, wherein the video server supplies video information on demand to the selected one signal modulator.

38. A system comprising the broadband data switch of claim 30 and a plurality of modem/diplexers each associated with a corresponding telephone and coupled to the broadband data switch through a respective telephone line, each modem/diplexer including a broadband signal modulator which modulates a first broadband data signal onto a respective telephone line and demodulates a second broadband data signal from the respective telephone line, wherein the broadband data switch receives the broadband connection request from a telephone user and causes one of the plurality of signal modulators connected to the respective telephone line to be coupled to the broadband data circuit.

39. A method for augmenting an existing telephone network to handle broadband data signals, wherein the existing telephone network includes a plurality of existing telephone lines and an existing telephone switch, the method comprising the steps of:

(1) providing a broadband data switch coupled between the existing telephone switch and the existing telephone lines and which includes a first plurality of telephone line ports each adapted to transmit and receive broadband information over one of the plurality of existing telephone lines, and a second plurality of telephone switch ports each adapted to be connected to the existing telephone switch, wherein telephone call signals are passed between each of a corresponding one of the first plurality of telephone line ports and a corresponding one of the second plurality of telephone switch ports;

(2) disconnecting the existing telephone lines from the existing telephone switch;

(3) reconnecting the existing telephone lines disconnected in step (2) to the first plurality of telephone line ports of the broadband data switch;

(4) connecting the second plurality of telephone switch ports to the existing telephone switch; and

(5) using the broadband data switch to transmit broadband data signals over the existing telephone lines without interfering with telephone call signals passed over the existing telephone lines.

40. The method of claim 39, wherein step (5) comprises the steps of:

(a) receiving at the broadband data switch a broadband connection request from a telephone user;

(b) transmitting a list of available users over a data channel on one of the existing telephone lines;

(c) selecting one of the available users; and

(d) in the broadband data switch, causing two of the first plurality of telephone line ports to be connected to each other.