Patent US6470083B1 successfully refreshed from Google Patents.
US6470083B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telecommunications off-hook and intrusion detection method and apparatus
Assignee: Elster Solutions LLC
•
Filing: 1997-12-24
•
Granted: 2002-10-22
•
Expires: 2017-12-24
Abstract
Abstract A method and apparatus to detect off-hook and intrusion conditions on a telephone line. A voltage to frequency converter is used to convert the voltage measured between the TIP and RING terminals of a telephone line to a frequency. The voltage is continuously monitored, once during each sample period. The measured frequency is compared to predetermined threshold values to determine the state of the telephone line. The predetermined threshold values are updated in each sample period.
Inventors
- 👤 Rodney C. Hemminger
- 👤 Albert H. Maxwell, Jr.
- 👤 Michael A. Murphy
- 👤 Thomas J. Van Heuklon
- 👤 Richard L. Tenor
- 👤 Todd P. Kelsey
- 👤 Fred F. Schleifer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:03
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/68; H04M1/738; H04M1/7385; H04M1/82
Claims Analysis
Total Claims: 77
Claim 1
Independent Claim
58 words
An apparatus for determining the state of a telephone line, comprising: voltage to frequency measurement means for measuring a voltage between a TIP terminal and a RING terminal on said telephone line and converting said voltage to a frequency; and comparator means for comparing said frequency with a first value to determine the state of said telephone line.
Claim 2
Independent Claim
58 words
An apparatus for determining the state of a telephone line, comprising: voltage to frequency measurement means for measuring a voltage between a TIP terminal and a RING terminal on said telephone line and converting said voltage to a frequency; and comparator means for comparing said frequency with a first value to determine the state of said telephone line.
Claim 3
Dependent Claim
46 words
The apparatus of claim 1 , where in said voltage to frequency measurement means comprises a voltage to frequency converter and said comparator means comprises a microcontroller, said microcontroller coupled to said voltage to frequency converter to receive said frequency from said voltage to frequency converter.
Claim 4
Dependent Claim
25 words
The apparatus of claim 2 , wherein said voltage to frequency converter comprises a RC relaxation oscillator having a tuning element and an active element.
Claim 5
Dependent Claim
20 words
The apparatus of claim 3 , wherein said tuning element is a diode and said active element is a comparator.
Claim 6
Dependent Claim
38 words
The apparatus of claim 3 , further comprising: a TIP/RING filter coupled between said TIP and RING terminals and said voltage to frequency measurement means; and a voltage isolator coupled between said tuning element and said active element.
Claim 7
Dependent Claim
21 words
The apparatus of claim 5 , wherein said voltage isolator comprises two coupling capacitors connected in series with said tuning element.
Claim 8
Dependent Claim
27 words
The apparatus of claim 1 , further comprising means for connecting a modem to said telephone line when said frequency is not less than said first value.
Claim 9
Dependent Claim
30 words
The apparatus of claim 7 , further comprising means for disconnecting said modem from said telephone line when a value responsive to said frequency becomes less than a second value.
Claim 10
Dependent Claim
29 words
The apparatus of claim 1 , further comprising means for preventing a telecommunications device from connecting on said telephone line when said frequency is less than said first value.
Claim 11
Dependent Claim
24 words
The apparatus of claim 1 , wherein said first value is determined responsive to said voltage between said TIP terminal and said RING terminal.
Claim 12
Independent Claim
66 words
An apparatus for determining an intrusion state of a telephone line having a telecommunications device connected thereon, comprising: voltage to frequency measurement means for measuring a voltage between a TIP terminal and a RING terminal on said telephone line and converting said voltage to a frequency; and comparator means for comparing said frequency with a threshold value to determine the intrusion state of said telephone line.
Claim 13
Independent Claim
66 words
An apparatus for determining an intrusion state of a telephone line having a telecommunications device connected thereon, comprising: voltage to frequency measurement means for measuring a voltage between a TIP terminal and a RING terminal on said telephone line and converting said voltage to a frequency; and comparator means for comparing said frequency with a threshold value to determine the intrusion state of said telephone line.
Claim 14
Dependent Claim
31 words
The apparatus of claim 11 , further comprising means for disconnecting said telecommunications device from said telephone line when said value responsive to said frequency is less than said threshold value.
Claim 15
Independent Claim
56 words
An apparatus for determining the state of a telephone line, comprising: measurement means comprising a tuning diode for measuring a voltage between a TIP terminal and a RING terminal on said telephone line; and comparator means for comparing a value responsive to said voltage with a first value to determine the state of said telephone line.
Claim 16
Independent Claim
56 words
An apparatus for determining the state of a telephone line, comprising: measurement means comprising a tuning diode for measuring a voltage between a TIP terminal and a RING terminal on said telephone line; and comparator means for comparing a value responsive to said voltage with a first value to determine the state of said telephone line.
Claim 17
Dependent Claim
49 words
The apparatus of claim 13 , wherein said value is a frequency, said measurement means further comprises a voltage to frequency converter and said comparator means comprises a microcontroller, said microcontroller coupled to said voltage to frequency converter to receive an output frequency from said voltage to frequency converter.
Claim 18
Dependent Claim
25 words
The apparatus of claim 14 , wherein said voltage to frequency converter comprises a RC relaxation oscillator having said tuning diode and an active element.
Claim 19
Dependent Claim
14 words
The apparatus of claim 15 , wherein and said active element is a comparator.
Claim 20
Dependent Claim
35 words
The apparatus of claim 15 , further comprising: a TIP/RING filter coupled between said TIP and RING terminals and said measurement means; and a voltage isolator coupled between said tuning diode and said active element.
Claim 21
Dependent Claim
21 words
The apparatus of claim 17 , wherein said voltage isolator comprises two coupling capacitors connected in series with said tuning diode.
Claim 22
Dependent Claim
27 words
The apparatus of claim 13 , further comprising means for connecting a modem to said telephone line when said value is not less than said first value.
Claim 23
Dependent Claim
26 words
The apparatus of claim 19 , further comprising means for disconnecting said modem from said telephone line when said value becomes less than a second value.
Claim 24
Dependent Claim
29 words
The apparatus of claim 13 , further comprising means for preventing a telecommunications device from connecting on said telephone line when said value is less than said first value.
Claim 25
Dependent Claim
24 words
The apparatus of claim 13 , wherein said first value is determined responsive to said voltage between said TIP terminal and said RING terminal.
Claim 26
Independent Claim
55 words
An apparatus for determining the state of a telephone line, comprising: measurement means comprising capacitive isolation for measuring a voltage between a TIP terminal and a RING terminal on said telephone line; and comparator means for comparing a value responsive to said voltage with a first value to determine the state of said telephone line.
Claim 27
Independent Claim
55 words
An apparatus for determining the state of a telephone line, comprising: measurement means comprising capacitive isolation for measuring a voltage between a TIP terminal and a RING terminal on said telephone line; and comparator means for comparing a value responsive to said voltage with a first value to determine the state of said telephone line.
Claim 28
Dependent Claim
48 words
The apparatus of claim 23 , wherein said value is a frequency, said measurement means comprises a voltage to frequency converter and said comparator means comprises a microcontroller, said microcontroller coupled to said voltage to frequency converter to receive an output frequency from said voltage to frequency converter.
Claim 29
Dependent Claim
25 words
The apparatus of claim 24 , wherein said voltage to frequency converter comprises a RC relaxation oscillator having a tuning element and an active element.
Claim 30
Dependent Claim
20 words
The apparatus of claim 25 , wherein said tuning element is a diode and said active element is a comparator.
Claim 31
Dependent Claim
53 words
The apparatus of claim 25 , further comprising: a TIP/RING filter coupled between said TIP and RING terminals and said measurement means, wherein said capacitive isolation comprises a voltage isolator coupled between said tuning element and said active element, said voltage isolator having two coupling capacitors connected in series with said tuning element.
Claim 32
Dependent Claim
27 words
The apparatus of claim 23 , further comprising means for connecting a modem to said telephone line when said value is not less than said first value.
Claim 33
Dependent Claim
26 words
The apparatus of claim 28 , further comprising means for disconnecting said modem from said telephone line when said value becomes less than a second value.
Claim 34
Dependent Claim
29 words
The apparatus of claim 23 , further comprising means for preventing a telecommunications device from connecting on said telephone line when said value is less than said first value.
Claim 35
Dependent Claim
24 words
The apparatus of claim 23 , wherein said first value is determined responsive to said voltage between said TIP terminal and said RING terminal.
Claim 36
Independent Claim
88 words
An apparatus for detecting an off-hook condition and an intrusion condition on a telephone line, comprising: a voltage to frequency converter for measuring a voltage on said telephone line and converting said voltage to a frequency, the voltage to frequency converter comprises a RC relaxation oscillator having a tuning diode and a comparator; and a microcontroller coupled to said voltage to frequency converter for receiving said frequency and determining whether at least one of an off-hook and intrusion condition exists on said telephone line responsive to said frequency.
Claim 37
Independent Claim
88 words
An apparatus for detecting an off-hook condition and an intrusion condition on a telephone line, comprising: a voltage to frequency converter for measuring a voltage on said telephone line and converting said voltage to a frequency, the voltage to frequency converter comprises a RC relaxation oscillator having a tuning diode and a comparator; and a microcontroller coupled to said voltage to frequency converter for receiving said frequency and determining whether at least one of an off-hook and intrusion condition exists on said telephone line responsive to said frequency.
Claim 38
Dependent Claim
15 words
The apparatus of claim 32 , wherein said voltage is a TIP to RING voltage.
Claim 39
Dependent Claim
35 words
The apparatus of claim 32 , further comprising a common mode filter coupled between said telephone line and said voltage to frequency converter, and a voltage isolator coupled between said tuning diode and said comparator.
Claim 40
Dependent Claim
23 words
The apparatus of claim 32 , further comprising means to connect a modem to said telephone line when no off-hook condition is detected.
Claim 41
Dependent Claim
23 words
The apparatus of claim 35 , further comprising means to disconnect said modem from said telephone line when an intrusion condition is detected.
Claim 42
Dependent Claim
20 words
The apparatus of claim 32 , wherein said voltage to frequency converter measures said voltage at a predetermined sampling rate.
Claim 43
Dependent Claim
18 words
The apparatus of claim 37 , wherein said predetermined sampling rate is one measurement every {fraction (1/16)} seconds.
Claim 44
Dependent Claim
38 words
The apparatus of claim 32 , wherein said off-hook condition is detected when said frequency drops below a first threshold and said intrusion condition is detected when a value responsive to said frequency drops below a second threshold.
Claim 45
Dependent Claim
29 words
The apparatus of claim 32 , further comprising memory to store frequency and voltage data used by said microcontroller in the detection of said off-hook and said intrusion conditions.
Claim 46
Independent Claim
89 words
An apparatus for determining the state of a telephone line having a TIP terminal and a RING terminal, comprising: a measuring device that measures a voltage between the TIP terminal and the RING terminal on said telephone line; a comparator that compares a value responsive to said voltage with a first value to determine the state of said telephone line; and a capacitor coupled between the measuring device and the capacitor, the capacitor providing electrical isolation, whereby the TIP and RING terminals may be free of a power supply.
Claim 47
Independent Claim
89 words
An apparatus for determining the state of a telephone line having a TIP terminal and a RING terminal, comprising: a measuring device that measures a voltage between the TIP terminal and the RING terminal on said telephone line; a comparator that compares a value responsive to said voltage with a first value to determine the state of said telephone line; and a capacitor coupled between the measuring device and the capacitor, the capacitor providing electrical isolation, whereby the TIP and RING terminals may be free of a power supply.
Claim 48
Dependent Claim
47 words
The apparatus of claim 41 , wherein said value is a frequency, said measuring device comprises a voltage to frequency converter and said comparator comprises a microcontroller, said microcontroller coupled to said voltage to frequency converter to receive an output frequency from said voltage to frequency converter.
Claim 49
Dependent Claim
34 words
The apparatus of claim 42 , wherein said voltage to frequency converter comprises a RC relaxation oscillator having a tuning element and an active element and the voltage to frequency converter comprises the capacitor.
Claim 50
Dependent Claim
20 words
The apparatus of claim 43 , wherein said tuning element is a diode and said active element is a comparator.
Claim 51
Dependent Claim
35 words
The apparatus of claim 43 , further comprising: a TIP/RING filter coupled between said TIP and RING terminals and said measuring device; and a voltage isolator coupled between said tuning element and said active element.
Claim 52
Dependent Claim
21 words
The apparatus of claim 45 , wherein said voltage isolator comprises two coupling capacitors connected in series with said tuning element.
Claim 53
Dependent Claim
27 words
The apparatus of claim 41 , further comprising means for connecting a modem to said telephone line when said value is not less than said first value.
Claim 54
Dependent Claim
26 words
The apparatus of claim 47 , further comprising means for disconnecting said modem from said telephone line when said value becomes less than a second value.
Claim 55
Dependent Claim
29 words
The apparatus of claim 41 , further comprising means for preventing a telecommunications device from connecting on said telephone line when said value is less than said first value.
Claim 56
Dependent Claim
24 words
The apparatus of claim 41 , wherein said first value is determined responsive to said voltage between said TIP terminal and said RING terminal.
Claim 57
Independent Claim
104 words
An apparatus for determining the state of a signal-carrying line having an isolation barrier separating the signal-carrying line into a side near a first and second terminal, and a side away from the first and second terminals, comprising: measurement means for measuring a voltage between the first and second terminals, said measurement means being free of a power supply on said side near the first and second terminals, the measurement means comprising a voltage to frequency converter that converts the measured voltage to a frequency; and comparator means for comparing the frequency with a first value to determine the state of said signal-carrying line.
Claim 58
Independent Claim
104 words
An apparatus for determining the state of a signal-carrying line having an isolation barrier separating the signal-carrying line into a side near a first and second terminal, and a side away from the first and second terminals, comprising: measurement means for measuring a voltage between the first and second terminals, said measurement means being free of a power supply on said side near the first and second terminals, the measurement means comprising a voltage to frequency converter that converts the measured voltage to a frequency; and comparator means for comparing the frequency with a first value to determine the state of said signal-carrying line.
Claim 59
Dependent Claim
32 words
The apparatus of claim 51 , wherein said comparator means comprises a microcontroller, said microcontroller coupled to said voltage to frequency converter to receive the frequency from said voltage to frequency converter.
Claim 60
Dependent Claim
38 words
The apparatus of claim 52 , wherein said voltage to frequency converter comprises a RC relaxation oscillator having a tuning element and an active element, said tuning element is a diode and said active element is a comparator.
Claim 61
Dependent Claim
34 words
The apparatus of claim 53 , further comprising: a filter coupled between said first and second terminals and said measurement means; and a voltage isolator coupled between said tuning element and said active element.
Claim 62
Dependent Claim
21 words
The apparatus of claim 54 , wherein said voltage isolator comprises two coupling capacitors connected in series with said tuning element.
Claim 63
Dependent Claim
27 words
The apparatus of claim 51 , further comprising means for connecting a device to said signal-carrying line when said frequency is not less than said first value.
Claim 64
Dependent Claim
26 words
The apparatus of claim 56 , further comprising means for disconnecting said device from said signal-carrying line when said frequency becomes less than a second value.
Claim 65
Dependent Claim
28 words
The apparatus of claim 51 , further comprising means for preventing a device from connecting on said signal-carrying line when said frequency is less than said first value.
Claim 66
Dependent Claim
22 words
The apparatus of claim 51 , wherein said first value is determined responsive to said voltage between said first and second terminals.
Claim 67
Independent Claim
56 words
A method for detecting the state of a telephone line, comprising the steps of: measuring a voltage between a TIP terminal and a RING terminal on said telephone line; converting said voltage to a frequency using a voltage to frequency converter; comparing said frequency with a threshold value to determine the state of said telephone line.
Claim 68
Independent Claim
56 words
A method for detecting the state of a telephone line, comprising the steps of: measuring a voltage between a TIP terminal and a RING terminal on said telephone line; converting said voltage to a frequency using a voltage to frequency converter; comparing said frequency with a threshold value to determine the state of said telephone line.
Claim 69
Dependent Claim
49 words
The method of claim 60 , further comprising the steps of: connecting a modem to said telephone line when said frequency is not less than said threshold value; and disconnecting said modem from said telephone line when a value responsive to said frequency becomes less than a second value.
Claim 70
Dependent Claim
16 words
The method of claim 60 , wherein said voltage is measured at a predetermined sampling rate.
Claim 71
Dependent Claim
18 words
The method of claim 62 , wherein said predetermined sampling rate is one measurement every {fraction (1/16)} seconds.
Claim 72
Dependent Claim
27 words
The method of claim 60 , further comprising the step of setting said first value responsive to said voltage between said TIP terminal and said RING terminal.
Claim 73
Independent Claim
123 words
A method for detecting the state of a telephone line, comprising the steps of: measuring a voltage between a TIP terminal and a RING terminal on said telephone line; comparing a value responsive to said voltage with one of a first threshold value and a second threshold value to determine the state of said telephone line; connecting a telecommunications device to said telephone line when said value is not less than said first threshold value; disconnecting said telecommunications device from said telephone line when said value becomes less than said second threshold value; and adjusting said first threshold value and said second threshold value based on the state of said telephone line and said voltage between said TIP terminal and said RING terminal.
Claim 74
Independent Claim
123 words
A method for detecting the state of a telephone line, comprising the steps of: measuring a voltage between a TIP terminal and a RING terminal on said telephone line; comparing a value responsive to said voltage with one of a first threshold value and a second threshold value to determine the state of said telephone line; connecting a telecommunications device to said telephone line when said value is not less than said first threshold value; disconnecting said telecommunications device from said telephone line when said value becomes less than said second threshold value; and adjusting said first threshold value and said second threshold value based on the state of said telephone line and said voltage between said TIP terminal and said RING terminal.
Claim 75
Independent Claim
60 words
A method for determining an intrusion state of a telephone line having a telecommunications device connected thereon, comprising the steps of: measuring a voltage between a TIP terminal and a RING terminal on said telephone line and converting said voltage to a frequency; and comparing said frequency with a threshold value to determine the intrusion state of said telephone line.
Claim 76
Independent Claim
60 words
A method for determining an intrusion state of a telephone line having a telecommunications device connected thereon, comprising the steps of: measuring a voltage between a TIP terminal and a RING terminal on said telephone line and converting said voltage to a frequency; and comparing said frequency with a threshold value to determine the intrusion state of said telephone line.
Claim 77
Dependent Claim
28 words
The method of claim 66 , further comprising the step of disconnecting said telecommunications device from said telephone line when said frequency is less than said threshold value.
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