Automatically testing telephone lines

• US 5,073,919 A
• Filed: 10/10/1990
• Issued: 12/17/1991
• Est. Priority Date: 10/10/1990
• Status: Expired due to Term

• Current Assignee: Tollgrade Communications Incorporated (Enghouse Systems Limited)
• Original Assignee: Teradyne Incorporated
• Inventors: Hagensick, Thomas E.
• Primary Examiner(s): SCHREYER, STAFFORD
• Application Number:
  US07/595,246
• Time in Patent Office: 433 Days
• Field of Search: 379/23, 379/21, 379/24, 379/27, 379/28, 379/29, 379/30, 379/6
• US Class Current: 379/29.01
• CPC Class Codes: H04M 1/24 Arrangements for testing
• CPC Class Codes: H04M 3/30 for subscriber's lines , for the local loop

Abstract

A method of testing a telephone line including installing a test call unit at an end of the telephone line at which a customer'"'"'s equipment is connected, automatically initiating a telephone line test at the module, performing the telephone line test, and transmitting the results of the line test over the telephone line.

Claims

1. A method of testing a telephone line comprising

installing a test call unit at an end of said telephone line at which a customer'"'"'s equipment is connected,

automatically initiating a telephone line test at said test call unit,

performing said telephone line test, said performing including measuring telephone line characteristics by detectors in said test call unit, and

transmitting results of tests by said detectors over said telephone line to a call collection unit.

2. The method of claim 1 wherein said test is initiated at a predetermined time by a clock in said test call unit.

3. The method of claim 2 wherein said test call unit initiates line tests according to a predetermined schedule.

4. The method of claim 1 wherein said characteristics include line voltage.

5. The method of claim 4 further comprising determining if said telephone is in use or is idle from the results of measurement of said line voltage.

6. The method of claim 2 wherein said characteristics include idle line noise.

7. The method of claim 1 wherein said performing includes taking the line off-hook at said test call unit, and said characteristics include minimum line current off-hook.

8. The method of claim 1 wherein said performing includes taking the line off-hook at said test call unit, and said characteristics include the existence of a dial tone.

9. The method of claim 1 wherein said performing includes taking the line off-hook at said test call unit, and said characteristics include the time from going off-hook to the initiation of a dial tone.

10. The method of claim 1 wherein said performing includes

taking said telephone line off-hook at said test call unit,

dialing a call collection unit from said test call unit, and

establishing a connection between the test call unit and the call collection unit.

11. The method of claim 10 wherein said performing includes making a quiet line noise measurement.

12. The method of claim 10 wherein said performing includes sending a data message over said telephone line between said call collection unit and said test call unit and checking the accuracy of the message received.

13. The method of claim 12 wherein said data message is sent from said call collection unit to said test call unit and is then resent from said test call unit to said call collection unit.

14. The method of claim 12 wherein said data message is sent over said telephone line as a modulated analog signal.

15. The method of claim 12 wherein said data message is sent over said telephone line as a modulated analog signal at different baud rates.

16. The method of claim 12 wherein said data message is sent at different amplitudes of the data signal to determine a minimum amplitude at which intelligible data transmission occurs.

17. The method of claim 10 wherein a dual-tone multi-frequency signal is sent over said telephone line between said test call unit and said call collection unit, and a characteristic of said signal is sensed after transmission over said telephone line.

18. The method of claim 17 wherein a plurality of different dual-tone multi-frequency signals are sent over said telephone line between said test call unit and said call collection unit, and characteristics of said signals are sensed after transmission over said telephone line.

19. The method of claim 18 wherein said characteristics of said signals sensed after transmission over said telephone line include the amplitude at different frequencies.

20. The method of claim 17 wherein said dual-tone multi-frequency signal is sent from said test call unit and is received by and sensed at said call collection unit.

21. The method of claim 18 wherein said dual-tone multi-frequency signal is sent from said test call unit and is received by and sensed at said call collection unit.

22. The method of claim 1 wherein said installing includes

electrically connecting said test call unit to said end of said telephone line,

taking said telephone line off-hook at said test call unit,

dialing a control unit and establishing a connection between said test call unit and said control unit, and

sending a station identification message over said telephone line to said control unit.

23. The method of claim 22 wherein said installing includes sending a station identification message over said line from said control unit.

24. The method of claim 22 wherein said test call unit includes a clock, and wherein said installing includes sending a message indicating timing for initiating a line test at said test call unit.

25. The method of claim 24 wherein said message indicates a frequency at which to periodically initiate line tests.

26. The method of claim 24 wherein said message indicates the time of day and the date, and said clock is set by the time of day and date of said message.

27. The method of claim 22 wherein said installing includes sending a message identifying a call collection unit with which said test call unit is assigned to perform said line test.

28. The method of claim 27 wherein said installing includes sending a message identifying the telephone number of a call control unit to be called in the event of a default condition of the test call unit or a default condition of a call collection unit with which said test call unit performs tests.

29. The method of claim 1 wherein a plurality of test call units are installed at ends of said telephone lines, and said plurality automatically initiate and perform telephone line tests and transmit results of tests to said call collection unit, and wherein test call summaries are automatically, periodically sent from said call collection unit to a control unit.

30. The method of claim 29 wherein said control unit automatically, periodically generates fault reports based upon said test call summaries and transmits them to a telephone operations support systems unit

31. The method of claim 29 wherein said control unit automatically generates fault reports and transmits them to a security system control unit.

32. A test call unit for testing a telephone line comprising

a termination for making electrical access to an end of said telephone line at which a customer'"'"'s equipment is connected,

an initiation circuit for automatically initiating a telephone line test,

a line test circuit that is connected to said termination and said initiation circuit and is responsive to said initiation circuit to perform said line test, said line test circuit including detectors that measure telephone line characteristics, and

means for transmitting results of tests by said line test circuit over said telephone line to a call collection unit.

33. The unit of claim 32 wherein said initiation circuit includes a clock for initiating a line test at said test module at a predetermined time.

34. The unit of claim 32 wherein said line test circuit includes a detector that measures line voltage.

35. The unit of claim 32 wherein said line test circuit includes a detector that measures idle line noise.

36. The unit of claim 32 wherein said line test circuit includes a detector that measures minimum line current off-hook.

37. The unit of claim 32 wherein said line test circuit includes a detector that measures the existence of a dial tone.

38. The unit of claim 32 further comprising means for taking said telephone line off-hook at said test call unit, and wherein said line test circuit includes a detector that measures the time from going off-hook to the initiation of a dial tone.

39. The unit of claim 32 further comprising

means for taking said telephone line off-hook at said test call unit,

means for dialing a call collection unit from said test call unit, and

means for establishing a connection between the test call unit and the call collection unit.

40. The unit of claim 39 wherein said line test circuit includes means for making a quiet line noise measurement.

41. The unit of claim 39 further comprising a multi-frequency sender.

42. An automatic telephone line test system comprising

a plurality of test call units installed at remote ends of respective telephone lines, each said unit comprising an initiation circuit for automatically initiating a telephone line test, and a line test circuit that is connected to said telephone line and said initiation circuit and is responsive to said initiation circuit to perform said line test, and

a call collection unit connected to communicate with said test call units over said telephone lines and including means to interact with said test call units relative to telephone line tests.

43. The system of claim 42 wherein said call collection unit includes means to send a data message over a said telephone line to a said test call unit, and said line test circuit includes means to receive said data message and transmit it back over said telephone line to said call collection unit.

44. The system of claim 43 wherein said test call units include means to transmit the results of telephone line tests, and said call collection unit includes means to receive said results.

45. The system of claim 44 further comprising a control unit connected to communicate with said call collection unit, said call collection unit including means for generating and transmitting test call summaries, said control unit including means for receiving said test call summaries.

46. The system of claim 45 wherein said control unit includes means for automatically generating fault reports and transmitting them to a security system control unit.

47. The system of claim 46 wherein said control unit includes means to communicate with said test call units over said telephone lines.