Method and system for providing DC power on local telephone lines

• US 7,317,793 B2
• Filed: 04/01/2003
• Issued: 01/08/2008
• Est. Priority Date: 01/30/2003
• Status: Expired due to Fees

• Current Assignee: Conversant Intellectual Property Management Inc (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: SercoNet Limited (Yehuda Binder, MBA)
• Inventors: Binder, Yehuda, Hazani, Ami, Kofman, Semion
• Primary Examiner(s): SINGH, RAMNANDAN P
• Application Number:
  US10/403,526
• Publication Number:
  US 20040151305A1
• Time in Patent Office: 1,743 Days
• Field of Search: 379/413, 379/102.04, 379/169, 379/186, 379/318, 379/322, 379/348, 379/93.36, 379/106.04, 379/413.04
• US Class Current: 379/413
• CPC Class Codes: H04M 19/08 with current supply sources at the substations generating ringing current H04M19/04
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Abstract

A system for providing DC power on local telephone lines, such as telephone lines in a building or office, for powering devices and circuitry associated with communications over those telephone lines, as well as other functions. Desired voltage and power levels are supplied over local telephone lines by separating the DC power component from the central office or private branch exchange with a DC blocking filter while passing all AC telephony signals. A distinct DC power is then imposed over the telephone line for powering both the telephony service as well as other loads. Conventional telephone off-hook detection is simulated for compatibility with the central office or private branch exchange. The functions required may be integrated, partially or fully within a telephone outlet.

Claims

1. A network for coupling a telephone set to a telephone service, comprising:

a wire pair connected for concurrently carrying an analog telephone signal to and from the telephone service and a DC power signal;

a connection point for connecting the network to the telephone service;

a power supply coupler DC coupled at a point of said wire pair for coupling DC power into said wire pair;

an AC Pass and DC Stop device connected in series between said wire pair and said connection point for substantially conducting only AC telephony signals and blocking DC flow from the telephone service into said wire pair, said AC Pass and DC Stop device being connected between the point at which said power supply coupler is DC coupled to said wire pair and said connectiom point;

a load coupler DC coupled to said wire pair for coupling DC power to a load from said wire pair, independently of the hook state of the telephone set; and

a telephone coupler for coupling the telephone set to said wire pair for passing only analog telephony signals between said wire pair and the telephone set while limiting the DC power supplied to the telephone set to a level suitable for proper telephone operation, an off-hook signaling circuit connected to bypass said AC Pass and DC Stop device for supplying an off-hook signal to the telephone services when the telephone set is off-hook, wherein said power supply coupler supplies all of the power required by the load and the telephone set.

2. The network of claim 1, wherein the load is coupled to the load coupler and is one of:

a part of the telephone set; and

a telephone line modem.

3. The network of claim 1, further comprising:

off-hook detector means couplable to the telephone set for detecting an off-hook condition of the telephone set;

off-hook transmitter means coupled to said off-hook detector means and to said wire pair for supplying an off-hook indication to said wire pair in response to detection of an off-hook condition by said off-hook detector means;

off-hook receiver means coupled to said wire pair for receiving the off-hook indication supplied by said off-hook transmitter means; and

off-hook simulator means coupled to said off-hook receiver means for supplying a simulated off-hook indication to the telephone service in response to receipt of the off-hook indication by said off-hook receiver means.

4. The network of claim 3, wherein the off-hook indication supplied by said off-hook transmitter means is a signal composed of one or more tones.

5. The network of claim 3, wherein said off-hook indication supplied by said off-hook transmitter means is provided by a variable impedance that assumes a selected value to produce the off-hook indication.

6. The network of claim 3, wherein the off-hook indication supplied by said off-hook transmitter means is a message sent over a data communication network.

7. The network of claim 6, wherein the data communication network uses said wire pair as a communication medium.

8. Apparatus for supplying to a telephone service an indication of an off-hook condition of a telephone set that is connected to the telephone service by a network that includes a medium that does not allow DC off-hook signaling from the telephone set directly to the telephone service, said apparatus comprising:

off-hook detector means couplable to the telephone set for detecting an off-hook condition of the telephone set;

off-hook transmitter means coupled to said off-hook detector means and to the medium for supplying an AC off-hook indication signal to the medium in response to detection of an off-hook condition by said off-hook detector means;

off-hook receiver means couplable to the medium for receiving the AC off-hook indication signal supplied by said off-hook transmitter means; and

off-hook simulator means coupled to said off-hook receiver means for supplying a simulated off-hook indication to the telephone service in response to receipt of the off-hook indication by said off-hook receiver means.

9. The apparatus of claim 8, wherein the off-hook indication supplied by said off-hook transmitter means is a signal composed of one or more tones.

10. The apparatus of claim 8, wherein said off-hook indication supplied by said off-hook transmitter means is provided by a variable impedance that assumes a selected value to produce the off-hook indication.

11. The apparatus of claim 8, wherein the off-hook indication supplied by said off-hook transmitter means is a message sent over a data communication network.

12. The apparatus of claim 11, wherein the medium is a wire pair and the data communication network uses said wire pair as a communication medium.

13. A power unit device connectable in series between a telephone service interface and a wire pair of a network for connecting a telephone set to a telephone service, said device comprising:

an AC Pass and DC Stop device connectable in series between the wire pair and the interface for substantially conducting only AC telephony signals and blocking DC flow from the telephone service into the wire pair; and

a power supply coupler DC couplable to the wire pair to couple DC power into the wire pair, the DC power including a DC telephony component conducted over the wire pair to the telephone set and a second DC power component conducted over the wire pair to a load that is distinct from the telephone set an off-hook signaling circuit connected to bypass said AC Pass and DC Stop device for supplying an off-hook signal to the telephone service when the telephone set is off-hook.

14. The device of claim 13 integrated into one of:

a PBX;

a cable modem;

a set top box;

a DSL modem;

a VoIP MTA; and

a telephone outlet.

15. An outlet comprising the power unit device of claim 13.

16. The device of claim 13 in combination with:

off-hook receiver means couplable to the wire pair for receiving an off-hook indication when the telephone set is off-hook; and

off-hook simulator means coupled to said off-hook receiver means and to the interface for supplying a simulated off-hook indication to the telephone service in response to receipt of the off-hook indication by said off-hook receiver means.

17. The device of claim 16, wherein the off-hook indication is a signal composed of one or more tones.

18. The device of claim 16, wherein said off-hook indication is provided by a variable impedance that assumes a selected value to produce the off-hook indication.

19. The device of claim 16, wherein the off-hook indication is a message sent over a data communication network.

20. The device of claim 19, wherein the data communication network uses the wire pair as a communication medium.

21. Apparatus for supplying to a telephone service an indication of an off-hook condition of a telephone set that is connected to the telephone service by a network that includes a medium that does not allow DC off-hook signaling from the telephone set directly to the telephone service, said apparatus comprising:

off-hook receiver means couplable to the medium for receiving an AC signal constituting an off-hook indication when the telephone set is off-hook; and

off-hook simulator means coupled to said off-hook receiver means and to the medium for supplying a simulated off-hook indication to the telephone service in response to receipt of the off-hook indication by said off-hook receiver means.

22. The apparatus of claim 21, wherein the off-hook indication is a signal composed of one or more tones.

23. The apparatus of claim 21, wherein said off-hook indication is provided by a variable impedance that assumes a selected value to produce the off-hook indication.

24. The apparatus of claim 21, wherein the off-hook indication is a message sent over a data communication network.

25. The apparatus of claim 24, wherein the medium is a wire pair and the data communication network uses the wire pair as a communication medium.

26. The apparatus of claim 21 integrated into one of:

a PBX;

a cable modem;

a set top box;

a DSL modem;

a VoIP MTA; and

a telephone outlet.

27. An outlet comprising the apparatus of claim 21.

28. Apparatus for supplying to a telephone service an indication of an off-hook condition of a telephone set that is connected to the telephone service by a network that includes a medium that does not allow DC off-hook signaling from the telephone set directly to the telephone service and a wire pair connecting the telephone set to the medium, said apparatus comprising:

off-hook detector means couplable to the telephone set for detecting an off-hook condition of the telephone set; and

off-hook transmitter means coupled to said off-hook detector means and to the wire pair for supplying an AC off-hook indication signal to the wire pair in response to detection of an off-hook condition by said off-hook detector means.

29. The apparatus of claim 28, wherein the off-hook indication is a signal composed of one or more tones.

30. The apparatus of claim 28, wherein the off-hook indication is a message sent over a data communication network.

31. The apparatus of claim 30, wherein the medium is a wire pair and the data communication network uses the wire pair as a communication medium.

32. The apparatus of claim 28 integrated into one of:

a telephone set; and

a telephone outlet.

33. An outlet comprising the apparatus of claim 28.

34. A method for carrying DC power over a wire pair of a network for coupling a telephone set to a telephone service, the network having a connection point for connecting the network to the telephone service, said method comprising:

DC coupling a power supply coupler at a point of the wire pair for coupling DC power into the wire pair;

connecting an AC Pass and DC Stop device in series between the wire pair and the connection point, such that the AC Pass and DC Stop device is connected between the point at which the power supply coupler is DC coupled to the wire pair and the connection point, for substantially conducting only AC telephony signals and blocking DC flow from the telephone service into the wire pair;

DC coupling a load coupler to the wire pair for coupling DC power to a load from said wire pair independently of the hook state of the telephone set; and

coupling a telephone coupler to the wire pair for coupling the telephone set to the wire pair for passing only analog telephony signals between the wire pair and the telephone set supplying an off-hook signal to the telephone service when the telephone set is off-hook via an off-hook signaling circuit that bypasses the AC Pass and DC Stop device.

35. The method of claim 34 further comprising coupling the load to the load coupler, and wherein the load is one of:

a part of the telephone set; and

a telephone line modem.

36. The method of claim 34, further comprising the steps of:

coupling off-hook detector means to the telephone set for detecting an off-hook condition of the telephone set;

coupling off-hook transmitter means to said off-hook detector means and to said wire pair for supplying an off-hook indication to said wire pair in response to detection of an off-hook condition by said off-hook detector means;

coupling off-hook receiver means to said wire pair for receiving the off-hook indication supplied by said off-hook transmitter means; and

coupling off-hook simulator means to said off-hook receiver means for supplying a simulated off-hook indication to the telephone service in response to receipt of the off-hook indication by said off-hook receiver means.

37. The method of claim 36, wherein the off-hook indication supplied by said off-hook transmitter means is a signal composed of one or more tones.

38. The network of claim 36, wherein said off-hook indication supplied by said off-hook transmitter means is provided by a variable impedance that assumes a selected value to produce the off-hook indication.

39. The network of claim 36, wherein the off-hook indication supplied by said off-hook transmitter means is a message sent over a data communication network.

40. The network of claim 39, wherein the data communication network uses said wire pair as a communication medium.

41. A network for coupling a telephone set to a telephone service, the service providing an analog telephone signal having an AC component and a first DC component, said network comprising:

a wire pair connected for carrying DC power and the AC component of the analog telephone signal;

a connection point connected between the network and the telephone service for passing the telephone signal to the network;

a power supply coupler DC coupled at a point of said wire pair to said wire pair for coupling DC power into said wire pair;

an AC Pass and DC Stop device connected in series between said wire pair and said connection point for passing only the AC component and blocking the first DC component, said AC Pass and DC Stop device being connected between the point at which said power supply coupler is DC coupled to said wire pair and said connection point;

a load coupler DC coupled to said wire pair for coupling DC power from said wire pair to a load; and

a telephone coupler for coupling the telephone set to said wire pair for passing only the AC component between said wire pair and the telephone set and for supplying DC power from said wire pair to the telephone set while limiting the DC power supplied to the telephone set to a level suitable for proper telephone operation an off-hook signaling circuit connected to bypass said AC Pass and DC Stop device for supplying an off-hook signal to the telephone service when the telephone set is off-hook.