US3870838A
Expired / Lapsed
US
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Means and apparatus for fault locating pulse regenerators
Assignee: AT&T Inc
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Filing: 1974-03-11
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Granted: 1975-03-11
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Expires: 1994-03-11
Abstract
Abstract In order to locate a faulty pulse regenerator in a transmission system, random streams of test pulses having predetermined statistical variations are transmitted along the transmission system. By slowly varying the mean of a noise signal applied to a decision circuit which generates a first test pulse level when the noise voltage is above threshold and a second test pulse level when the noise voltage is below the threshold, a predetermined amplitude characteristic at the frequency at which the mean of the noise is varied can be imposed upon the distribution of test pulse levels generated by the decision circuit. A regenerator can be determined to be operative or faulty by comparing, at the frequency of the variation of the mean of the noise, the time-varying average signal derived from the regenerated test pulse stream with an anticipated signal.
Inventors
- 👤 Walter Leo Corwin
- 👤 Robert Emerson Keeler
- 👤 Philip Edward Rubin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:05
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/20; H04L25/24; H04L25/242; H04B; H04B17/00; H04B17/40; H04B17/401; H04B17/402; H04B17/404
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
144 words
A method for testing a pulse regenerator comprising the steps of generating a noise voltage having random voltage fluctuations, perturbing the mean of said noise voltage in a predetermined manner, applying to said regenerator at a fixed repetition rate at test instants random sequences of successive first test pulse levels and second test pulse levels, the probability that the first test pulse level being applied at a test instant and the probability that the second test pulse level being applied at said test instant being functionally determined by the mean of the perturbed noise voltage, deriving at the pulse regenerator a response to the successively applied random test pulse levels, comparing the derived response with an anticipated response to determine whether said regenerator is faulty, said anticipated response being determined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 2
Independent Claim
144 words
A method for testing a pulse regenerator comprising the steps of generating a noise voltage having random voltage fluctuations, perturbing the mean of said noise voltage in a predetermined manner, applying to said regenerator at a fixed repetition rate at test instants random sequences of successive first test pulse levels and second test pulse levels, the probability that the first test pulse level being applied at a test instant and the probability that the second test pulse level being applied at said test instant being functionally determined by the mean of the perturbed noise voltage, deriving at the pulse regenerator a response to the successively applied random test pulse levels, comparing the derived response with an anticipated response to determine whether said regenerator is faulty, said anticipated response being determined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 3
Independent Claim
144 words
A method for testing a pulse regenerator comprising the steps of generating a noise voltage having random voltage fluctuations, perturbing the mean of said noise voltage in a predetermined manner, applying to said regenerator at a fixed repetition rate at test instants random sequences of successive first test pulse levels and second test pulse levels, the probability that the first test pulse level being applied at a test instant and the probability that the second test pulse level being applied at said test instant being functionally determined by the mean of the perturbed noise voltage, deriving at the pulse regenerator a response to the successively applied random test pulse levels, comparing the derived response with an anticipated response to determine whether said regenerator is faulty, said anticipated response being determined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 4
Independent Claim
144 words
A method for testing a pulse regenerator comprising the steps of generating a noise voltage having random voltage fluctuations, perturbing the mean of said noise voltage in a predetermined manner, applying to said regenerator at a fixed repetition rate at test instants random sequences of successive first test pulse levels and second test pulse levels, the probability that the first test pulse level being applied at a test instant and the probability that the second test pulse level being applied at said test instant being functionally determined by the mean of the perturbed noise voltage, deriving at the pulse regenerator a response to the successively applied random test pulse levels, comparing the derived response with an anticipated response to determine whether said regenerator is faulty, said anticipated response being determined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 5
Independent Claim
136 words
A method for testing a pulse regenerator comprising the steps of generating a noise voltage having random voltage fluctuations, perturbing the mean of said noise voltage in a predetermined manner, comparing at fixed clock instants the perturbed noise voltage with a predetermined threshold, applying to said regenerator a first test pulse level at each clock instant when the perturbed noise voltage is greater than said predetermined threshold and a second test pulse level at each clock instant when said perturbed noise voltage is less than said predetermined threshold, deriving at the pulse regenerator a response to the successively applied test pulse levels, comparing the derived response with an anticipated response to determine whether said regenerator is faulty, said anticipated response being deTermined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 6
Independent Claim
136 words
A method for testing a pulse regenerator comprising the steps of generating a noise voltage having random voltage fluctuations, perturbing the mean of said noise voltage in a predetermined manner, comparing at fixed clock instants the perturbed noise voltage with a predetermined threshold, applying to said regenerator a first test pulse level at each clock instant when the perturbed noise voltage is greater than said predetermined threshold and a second test pulse level at each clock instant when said perturbed noise voltage is less than said predetermined threshold, deriving at the pulse regenerator a response to the successively applied test pulse levels, comparing the derived response with an anticipated response to determine whether said regenerator is faulty, said anticipated response being deTermined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 7
Independent Claim
218 words
A method for locating a faulty one of a plurality of pulse regenerators connected in tandem in a digital transmission system between a transmitting and receiving terminal by selectively testing each of said pulse regenerators, each of said pulse regenerators including means responsive to a unique audio frequency, said method comprising the steps of generating a noise voltage having random voltage fluctuations, recursively perturbing the mean of said noise voltage in a predetermined manner at the audio frequency at which the means of the pulse regenerator under test is uniquely responsive, comparing at fixed clock instants the perturbed noise voltage with a predetermined threshold, transmitting from said transmitting terminal on said transmission system a first test pulse level at each clock instant when said perturbed noise voltage is greater than said predetermined threshold and a second test pulse level at each clock instant when said noise voltage is less than said predetermined threshold, deriving at the pulse regenerator being tested a response to the successively transmitted pulse levels at the frequency at which the mean of said noise voltage is being perturbed, comparing the derived response with an anticipated response to determine whether the regenerator being tested is faulty, said anticipated response being determined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 8
Independent Claim
218 words
A method for locating a faulty one of a plurality of pulse regenerators connected in tandem in a digital transmission system between a transmitting and receiving terminal by selectively testing each of said pulse regenerators, each of said pulse regenerators including means responsive to a unique audio frequency, said method comprising the steps of generating a noise voltage having random voltage fluctuations, recursively perturbing the mean of said noise voltage in a predetermined manner at the audio frequency at which the means of the pulse regenerator under test is uniquely responsive, comparing at fixed clock instants the perturbed noise voltage with a predetermined threshold, transmitting from said transmitting terminal on said transmission system a first test pulse level at each clock instant when said perturbed noise voltage is greater than said predetermined threshold and a second test pulse level at each clock instant when said noise voltage is less than said predetermined threshold, deriving at the pulse regenerator being tested a response to the successively transmitted pulse levels at the frequency at which the mean of said noise voltage is being perturbed, comparing the derived response with an anticipated response to determine whether the regenerator being tested is faulty, said anticipated response being determined by the predetermined manner in which the mean of the noise voltage is perturbed.
Claim 9
Dependent Claim
178 words
Apparatus for generating a test signal comprising a noise source for generating an output noise voltage having random voltage fluctuations, a signal source for generating a stressing signal having predetermined amplitude variations at a predetermined audio frequency, means for perturbing the mean of the output noise voltage generated by said noise source with a predetermined amplitude characteristic in response to and at the frequency of said stressing signal, a clock circuit having a pulse repetition rate substantially greater than the frequency of said stressing signal, and pulse generation means for generating in response to said perturbed noise voltage a random test pulse stream having first and second pulse levels at the repetition rate of said clock circuit, the predetermined amplitude characteristic at which the mean of said noise voltage is perturbed being chosen such that the time-varying difference between the probability that the first pulse level is generated and the probability that the second pulse level is generated by said pulse generation means at each clock instant has the predetermined amplitude variations and frequency of the stressing signal.
Claim 10
Dependent Claim
178 words
Apparatus for generating a test signal comprising a noise source for generating an output noise voltage having random voltage fluctuations, a signal source for generating a stressing signal having predetermined amplitude variations at a predetermined audio frequency, means for perturbing the mean of the output noise voltage generated by said noise source with a predetermined amplitude characteristic in response to and at the frequency of said stressing signal, a clock circuit having a pulse repetition rate substantially greater than the frequency of said stressing signal, and pulse generation means for generating in response to said perturbed noise voltage a random test pulse stream having first and second pulse levels at the repetition rate of said clock circuit, the predetermined amplitude characteristic at which the mean of said noise voltage is perturbed being chosen such that the time-varying difference between the probability that the first pulse level is generated and the probability that the second pulse level is generated by said pulse generation means at each clock instant has the predetermined amplitude variations and frequency of the stressing signal.
Claim 11
Dependent Claim
177 words
Apparatus for generating a test signal comprising a noise source for generating an output noise voltage having random voltage fluctuations, a clock for generating clock pulses, a decision circuit having an input and output terminal for generating at the output terminal in response to a clock pulse a first test pulse level when a signal at said input terminal is above a predetermined threshold and a second test pulse level when the signal at said input terminal is below said predetermined threshold, a signal source for generating a stressing signal having predetermined amplitude variations at a frequency substantially below the frequency of said clock circuit, and means for combining said output noise voltage and said stressing signal to develop a noise signal at the input terminal of said decision circuit with a mean voltage that varies with a predetermined amplitude characteristic, the amplitude characteristic being chosen such that the test pulse levels generated at the output terminal of said decision circuit have an average value that has the predetermined amplitude variations and frequency of the stressing signal.
Claim 12
Dependent Claim
177 words
Apparatus for generating a test signal comprising a noise source for generating an output noise voltage having random voltage fluctuations, a clock for generating clock pulses, a decision circuit having an input and output terminal for generating at the output terminal in response to a clock pulse a first test pulse level when a signal at said input terminal is above a predetermined threshold and a second test pulse level when the signal at said input terminal is below said predetermined threshold, a signal source for generating a stressing signal having predetermined amplitude variations at a frequency substantially below the frequency of said clock circuit, and means for combining said output noise voltage and said stressing signal to develop a noise signal at the input terminal of said decision circuit with a mean voltage that varies with a predetermined amplitude characteristic, the amplitude characteristic being chosen such that the test pulse levels generated at the output terminal of said decision circuit have an average value that has the predetermined amplitude variations and frequency of the stressing signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |