Apparatus and method for supervising derived channel communications

• US 5,822,423 A
• Filed: 03/20/1996
• Issued: 10/13/1998
• Est. Priority Date: 03/20/1996
• Status: Expired due to Term

• Current Assignee: Numerex Investment Corp. (Sierra Wireless Incorporated)
• Original Assignee: Numerex Investment Corp. (Sierra Wireless Incorporated)
• Inventors: Jehnert, Walt, Darr, Roger Raymond, Hughey, Stephen A., Eakes, James W.
• Primary Examiner(s): Zele, Krista
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US08/618,867
• Time in Patent Office: 937 Days
• Field of Search: 379/352, 379/39, 379/59, 379/42, 379/49, 379/45, 379/106, 379/6, 379/27, 379/50
• US Class Current: 379/352
• CPC Class Codes: H04M 11/002 with telemetering systems telemetering in general G08C
• CPC Class Codes: H04M 11/04 with alarm systems, e.g. fire, police or burglar alarm systems

Abstract

A supervisory signal for a derived channel data reporting system is implemented as a tone having a frequency capable of transmission using a telephone signal communicating network, including networks incorporating digital equipment, at an attenuated level. The tone preferably has a frequency of from 200 Hz to 300 Hz, and is capable of operating in conjunction with biphase modulated (BPSK), frequency shift keyed (FSK) and multi-tone modulated (MLT) polling systems. Such frequencies are effectively communicated by conventional digital loop carrier systems, despite a limited frequency range, and are of a sufficient magnitude to be detected by the derived channel data reporting system.

Claims

1. A system for providing communication between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising:

means for selectively transmitting signals from the central location to different subscriber premises using a telephone signal communicating network;

means located at the subscriber premises, connected to the telephones and responsive to the transmitted signals, for retransmitting signals from the subscriber premises to the central location in an audible telephone frequency range and indicative of states of the instrumentalities, using the telephone signal communicating network;

means for transmitting a supervisory signal from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state, wherein the supervisory signal has a frequency which is transmitted by telephone signal communicating networks including digital transmission equipment having band pass filtration means which pass signals limited to the audible telephone frequency range, and wherein the supervisory signal is transmitted at an attenuated level; and

means responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state, for interrupting the transmission of the supervisory signal.

2. The system of claim 1 wherein the telephone signal communicating network includes digital transmission equipment having band pass filtration means associated therewith.

3. The system of claim 1 wherein the supervisory signal is transmitted from the subscriber premises during both on-hook and off-hook conditions of the telephone at the subscriber premises.

4. The system of claim 1 which further includes means for taking an event-responsive action at the central location responsive to interruption of the supervisory signal.

5. The system of claim 1 wherein the supervisory signal is at a frequency of from 200 Hz to 300 Hz.

6. The system of claim 1 wherein each of the subscriber premises are separately connected to the central location, and which further includes multiplexing means for selectively applying the transmitted signals to different subscriber premises, individually and in predetermined sequence, and for selectively receiving the responsive signals from the instrumentalities at a same one of the subscriber premises, in the same predetermined sequence.

7. The system of claim 1 which further includes means for sensing discontinuance of the supervisory signal, and means responsive to the means for sensing the discontinuance of the supervisory signal, for transmitting the signals from the central location to the individual subscriber'"'"'s premises.

8. The system of claim 1 wherein the transmitted signals are biphase modulated signals.

9. The system of claim 1 wherein the transmitted signals are frequency shift keyed signals.

10. The system of claim 1 wherein the transmitted signals are multi-tone modulated signals.

11. The system of claim 1 which further includes means for sensing the signals which are communicated between the central location and the subscriber premises, wherein the communicated signals have a level which is continuously variable between a minimum level and a maximum level, and means for dynamically adjusting the level of the supervisory signal responsive to increases and decreases in the sensed level of the communicated signals.

12. The system of claim 1 which further includes means for sensing the signals which are communicated between the central location and the subscriber premises, wherein the communicated signals have a level which is continuously variable between a minimum level and a maximum level, and means for dynamically adjusting the frequency of the supervisory signal responsive to increases and decreases in the sensed level of the communicated signals.

13. The system of claim 1 which further includes means for sensing the signals which are communicated between the central location and the subscriber premises, wherein the communicated signals have a level which is continuously variable between a minimum level and a maximum level, and means for dynamically adjusting the level and frequency of the supervisory signal responsive to increases and decreases in the sensed level of the communicated signals.

14. The system of claim 1 which further includes means for sensing activation of telephone equipment other than the telephones at the subscriber premises, and means responsive to the activation sensing means for temporarily interrupting communications between the central location and the subscriber premises.

15. The system of claim 1 wherein the band pass filtration means associated with the digital transmission equipment of the telephone signal communicating network passes frequencies in a range from 300 to 3200 Hz.

16. The system of claim 1 which further includes means for sensing off-hook conditions of the conventional telephone at the individual subscriber'"'"'s premises, and means responsive to the sensing means for inhibiting transmissions of the signals from the central location to the individual subscriber'"'"'s premises.

17. The system of claim 16 wherein the means located at the subscriber premises include means for advising the central location of hook status conditions of the telephones at the subscriber premises.

18. The system of claim 17 wherein the advising means is a carrier signal, separate from and in addition to the supervisory signal, at a frequency transmitted by the telephone signal communicating network.

19. The system of claim 18 wherein the carrier signal is only transmitted when the telephone at the individual subscriber'"'"'s premises is on-hook, and when the instrumentalities assume the second predetermined state.

20. The system of claim 16 wherein the supervisory signal is transmitted from the subscriber premises during the off-hook conditions of the telephones at the subscriber premises.

21. The system of claim 16 wherein the supervisory signal is transmitted from the subscriber premises during both on-hook and the off-hook conditions of the telephones at the subscriber premises.

22. The system of claim 16 which further includes means for sensing discontinuance of the supervisory signal during the sensing of the off-hook condition at the individual subscriber'"'"'s premises, and means responsive to the means for sensing the discontinuance of the supervisory signal, for transmitting the signals from the central location to the individual subscriber'"'"'s premises.

23. The system of claim 16 which further includes means for sensing discontinuance of the off-hook condition of the telephone at the individual subscriber'"'"'s premises, and means responsive to the means for sensing the discontinuance of the off-hook condition, for transmitting the signals from the central location to the individual subscriber'"'"'s premises.

24. The system of claim 23 wherein the means for sensing the discontinuance of the off-hook condition is associated with the means located at the subscriber premises.

25. A system for providing communication between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising:

means for selectively transmitting signals from the central location to different subscriber premises using a telephone signal communicating network;

means located at the subscriber premises, connected to the telephones and responsive to the transmitted signals, for retransmitting signals from the subscriber premises to the central location in an audible telephone frequency range and indicative of states of the instrumentalities, using the telephone signal communicating network;

means for transmitting a supervisory signal having a frequency capable of transmission using the telephone signal communicating network and an attenuated level, from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state, wherein the supervisory signal is a data containing series of bits; and

means responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state, for interrupting the transmission of the supervisory signal.

26. The system of claim 25 wherein the supervisory signal is an encrypted signal.

27. The system of claim 25 wherein the data containing series of bits includes an identification code corresponding to the means located at the individual subscriber'"'"'s premises.

28. The system of claim 25 wherein the means located at the subscriber premises include means for advising the central location of hook status conditions of the telephones at the subscriber premises, and wherein the data containing series of bits communicates the hook status conditions of the telephones at the subscriber premises to the central location.

29. The system of claim 25 wherein the means located at the subscriber premises include means for remotely monitoring equipment at the subscriber premises, and wherein the data containing series of bits communicates data associated with the remotely monitored equipment between the subscriber premises and the central location.

30. The system of claim 25 wherein the data containing series of bits establishes two-way communications between the central location and the subscriber premises.

31. A method for communicating between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising the steps of:

selectively transmitting signals from the central location to different subscriber premises using a telephone signal communicating network;

retransmitting signals from the subscriber premises to the central location, using the telephone signal communicating network and responsive to the transmitted signals, wherein the retransmitted signals are in an audible telephone frequency range and are indicative of states of the instrumentalities;

transmitting a supervisory signal having a frequency which is transmitted by telephone signal communicating networks including digital transmission equipment having band pass filtering which passes signals limited to the audible telephone frequency range, and an attenuated level, from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state; and

interrupting the transmission of the supervisory signal responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state.

32. The method of claim 31 wherein the telephone signal communicating network includes digital transmission equipment having band pass filtration means associated therewith.

33. The method of claim 31 which further includes the step of transmitting the supervisory signal from the subscriber premises during both on-hook and off-hook conditions of the telephone at the subscriber premises.

34. The method of claim 31 which further includes the step of taking an event-responsive action at the central location responsive to interruption of the supervisory signal.

35. The method of claim 31 wherein the supervisory signal is at a frequency of from 200 Hz to 300 Hz.

36. The method of claim 31 wherein each of the subscriber premises are separately connected to the central location, and which further includes the steps of selectively applying the transmitted signals to different subscriber premises, individually and in predetermined sequence, and selectively receiving the responsive signals from the instrumentalities at a same one of the subscriber premises, in the same predetermined sequence.

37. The method of claim 31 which further includes the steps of sensing discontinuance of the supervisory signal, and transmitting the signals from the central location to the individual subscriber'"'"'s premises responsive to sensing the discontinuance of the supervisory signal.

38. The method of claim 31 wherein the transmitted signals are biphase modulated signals.

39. The method of claim 31 wherein the transmitted signals are frequency shift keyed signals.

40. The method of claim 31 wherein the transmitted signals are multi-tone modulated signals.

41. The method of claim 31 which further includes the steps of sensing the signals which are communicated between the central location and the subscriber premises, wherein the communicated signals have a level which is continuously variable between a minimum level and a maximum level, and dynamically adjusting the level of the supervisory signal responsive to increases and decreases in the sensed level of the communicated signals.

42. The method of claim 31 which further includes the steps of sensing the signals which are communicated between the central location and the subscriber premises, wherein the communicated signals have a level which is continuously variable between a minimum level and a maximum level, and dynamically adjusting the frequency of the supervisory signal responsive to increases and decreases in the sensed level of the communicated signals.

43. The method of claim 31 which further includes the steps of sensing the signals which are communicated between the central location and the subscriber premises, wherein the communicated signals have a level which is continuously variable between a minimum level and a maximum level, and dynamically adjusting the level and frequency of the supervisory signal responsive to increases and decreases in the sensed level of the communicated signals.

44. The method of claim 31 which further includes the steps of sensing activation of telephone equipment other than the telephones at the subscriber premises, and temporarily interrupting communications between the central location and the subscriber premises responsive to sensing the activation of the telephone equipment.

45. The method of claim 31 wherein the band pass filtering associated with the digital transmission equipment of the telephone signal communicating network passes frequencies in a range from 300 to 3200 Hz.

46. The method of claim 31 which further includes the steps of sensing off-hook conditions of the conventional telephone at the individual subscriber'"'"'s premises, and inhibiting transmissions of the signals from the central location to the individual subscriber'"'"'s premises responsive to the sensing of the off-hook conditions.

47. The method of claim 46 which further includes the step of advising the central location of hook status conditions of the telephones at the subscriber premises responsive to signals detected at the subscriber premises.

48. The method of claim 47 wherein the advising of hook status conditions is performed by a carrier signal, separate from and in addition to the supervisory signal, at a frequency transmitted by the telephone signal communicating network.

49. The method of claim 48 which further includes the step of transmitting the carrier signal only when the telephone at the individual subscriber'"'"'s premises is on-hook, and when the instrumentalities assume the second predetermined state.

50. The method of claim 46 which further includes the step of transmitting the supervisory signal from the subscriber premises during the off-hook conditions of the telephones at the subscriber premises.

51. The method of claim 46 which further includes the step of transmitting the supervisory signal from the subscriber premises during both on-hook and the off-hook conditions of the telephones at the subscriber premises.

52. The method of claim 46 which further includes the steps of sensing discontinuance of the supervisory signal during the sensing of the off-hook condition at the individual subscriber'"'"'s premises, and transmitting the signals from the central location to the individual subscriber'"'"'s premises responsive to the sensing of the discontinuance of the supervisory signal.

53. The method of claim 46 which further includes the steps of sensing discontinuance of the off-hook condition of the telephone at the individual subscriber'"'"'s premises, and transmitting the signals from the central location to the individual subscriber'"'"'s premises responsive to the sensing of the discontinuance of the off-hook condition.

54. The method of claim 53 wherein the sensing of the discontinuance of the off-hook condition is performed at the subscriber premises, and which further includes the step of transmitting the sensing of the discontinuance of the off-hook condition to the central location.

55. A method for communicating between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising the steps of:

selectively transmitting signals from the central location to different subscriber premises using a telephone signal communicating network;

retransmitting signals from the subscriber premises to the central location, using the telephone signal communicating network and responsive to the transmitted signals, wherein the retransmitted signals are in an audible telephone frequency range and are indicative of states of the instrumentalities;

transmitting a supervisory signal having a frequency capable of transmission using the telephone signal communicating network and an attenuated level, from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state;

producing the supervisory signal as a data containing series of bits; and

interrupting the transmission of the supervisory signal responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state.

56. The method of claim 55 which further includes the step of encrypting the supervisory signal.

57. The method of claim 55 which further includes the step of providing the data containing series of bits with an identification code corresponding to the means located at the individual subscriber'"'"'s premises.

58. The method of claim 55 which further includes the steps of advising the central location of hook status conditions of the telephones at the subscriber premises by including the hook status conditions of the telephones at the subscriber premises in the data containing series of bits communicated to the central location.

59. The method of claim 55 which further includes the steps of remotely monitoring equipment at the subscriber premises, and communicating data associated with the remotely monitored equipment between the subscriber premises and the central location by including the data associated with the remotely monitored equipment in the data containing series of bits.

60. The method of claim 55 which further includes the step of establishing two-way communications between the central location and the subscriber premises using the data containing series of bits.

61. A system for providing communication between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising:

means for selectively transmitting signals from the central location to different subscriber premises using a telephone signal communicating network;

means located at the subscriber premises, connected to the telephones and responsive to the transmitted signals, for retransmitting signals from the subscriber premises to the central location in an audible telephone frequency range and indicative of states of the instrumentalities, using the telephone signal communicating network;

means for transmitting a supervisory signal having a frequency capable of transmission using the telephone signal communicating network and an attenuated level, from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state, wherein the frequency of the supervisory signal is from 200 Hz to 300 Hz; and

means responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state, for interrupting the transmission of the supervisory signal.

62. A system for providing communication between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising:

a telephone signal communicating network;

means for selectively transmitting signals from the central location to different subscriber premises using the telephone signal communicating network;

means located at the subscriber premises, connected to the telephones and responsive to the transmitted signals, for retransmitting signals from the subscriber premises to the central location in an audible telephone frequency range and indicative of states of the instrumentalities, using the telephone signal communicating network;

means for transmitting a supervisory signal having a frequency capable of transmission using the telephone signal communicating network with digital transmission equipment having band pass filtration means which passes signals limited to audible frequencies, and at an attenuated level, from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state; and

means responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state, for interrupting the transmission of the supervisory signal.

63. A method for communicating between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising the steps of:

selectively transmitting signals from the central location to different subscriber premises using a telephone signal communicating network;

retransmitting signals from the subscriber premises to the central location, using the telephone signal communicating network and responsive to the transmitted signals, wherein the retransmitted signals are in an audible telephone frequency range and are indicative of states of the instrumentalities;

transmitting a supervisory signal having a frequency capable of transmission using the telephone signal communicating network and an attenuated level, from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state, wherein the frequency of the supervisory signal is from 200 Hz to 300 Hz; and

interrupting the transmission of the supervisory signal responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state.

64. A method for communicating between a central location and instrumentalities other than a conventional telephone located at premises of telephone network subscribers, comprising the steps of:

selectively transmitting signals from the central location to different subscriber premises using a telephone signal communicating network;

retransmitting signals from the subscriber premises to the central location, using the telephone signal communicating network and responsive to the transmitted signals, wherein the retransmitted signals are in an audible telephone frequency range and are indicative of states of the instrumentalities;

transmitting a supervisory signal having a frequency capable of transmission using the telephone signal communicating network with digital transmission equipment having band pass filtering which passes signals limited to audible frequencies, and an attenuated level, from each of the subscriber premises to the central location, when the instrumentalities at the subscriber premises are in a first predetermined state; and

interrupting the transmission of the supervisory signal responsive to one of the instrumentalities at an individual subscriber'"'"'s premises assuming a second predetermined state.