Detection of bridged taps by frequency domain reflectometry
First Claim
1. A method of automatically identifying the position of each of at least one energy reflection location along a telecommunication wireline comprising the steps of:
- (a) generating a plurality of waveforms having respectively different frequencies;
(b) sequentially coupling each of the respectively different frequency waveforms generated in step (a), one at the time, to a first location of said telecommunication wireline;
(c) for each of said plurality of respectively different frequency waveforms sequentially coupled to said telecommunication wireline in step (b), measuring a variation in signal level at said first location of said telecommunication wireline; and
(d) performing frequency domain reflectometry (FDR) processing of variations in signal level as measured in step (c) for each of said plurality of respectively different frequency waveforms to determine the distance between said first location and said position of said at least one energy reflection location along said telecommunication wireline, and compensating said variation in signal level measured in step (c) for loss through said telecommunication wireline.
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Abstract
A test system automatically locates impedance mismatched, energy reflection discontinuities (e.g., bridged taps) along a wireline communication link, by coupling a linearly stepped sinusoidal waveform to a measurement location of the wireline link. The applied waveform propagates down the link and is reflected back from the energy reflection discontinuities. A line monitoring receiver coupled to the measurement location samples the response of the line to the swept waveform. A response processor executes a frequency domain reflectometry algorithm to analyze the frequency response of the wireline to the stepped frequency waveform. It then generates an output representative of distances from the measurement location to the bridged taps.
42 Citations
23 Claims
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1. A method of automatically identifying the position of each of at least one energy reflection location along a telecommunication wireline comprising the steps of:
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(a) generating a plurality of waveforms having respectively different frequencies;
(b) sequentially coupling each of the respectively different frequency waveforms generated in step (a), one at the time, to a first location of said telecommunication wireline;
(c) for each of said plurality of respectively different frequency waveforms sequentially coupled to said telecommunication wireline in step (b), measuring a variation in signal level at said first location of said telecommunication wireline; and
(d) performing frequency domain reflectometry (FDR) processing of variations in signal level as measured in step (c) for each of said plurality of respectively different frequency waveforms to determine the distance between said first location and said position of said at least one energy reflection location along said telecommunication wireline, and compensating said variation in signal level measured in step (c) for loss through said telecommunication wireline. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for automatically identifying energy reflection discontinuities along a telecommunication wireline comprising a test signal generator that is operative to generate a plurality of waveforms having respectively different frequencies, and to sequentially couple each of said different frequency waveforms, one at the time, to a measurement location of said telecommunication wireline, in response to which said wireline propagates said different frequency waveforms to said energy reflection discontinuities, said energy reflection discontinuities reflecting energy back to said measurement location, a line monitoring receiver coupled to said measurement location of said telecommunication wireline, and a response processor which is operative to execute a frequency domain reflectometry (FDR) algorithm to analyze a frequency response of said telecommunication wireline to said different frequency waveforms and generates an output representative of locations of said energy reflection discontinuities;
- and wherein
said test signal generator is operative to linearly step a sinusoidal waveform between a minimum frequency and a maximum frequency, so as to generate a plurality of sinusoidal waveforms having respectively different frequencies, and to sequentially couple each of said different frequency sinusoidal waveforms, one at the time, to said measurement location of said telecommunication wireline;
said line monitoring receiver is operative to store samples of the amplitude of the measured signal response of said telecommunication wireline in association with linear stepping of the frequency of said sinusoidal waveform;
said response processor is operative to weight said stored samples to excise any DC level therein and to remove discontinuities between start and end values; and
said response processor is operative to apply a loss compensation function to said weighted samples so as to compensate the frequency response characteristic of said telecommunication wireline represented thereby for loss over distance and frequency. - View Dependent Claims (13, 14, 15, 16, 17)
- and wherein
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18. A method of automatically identifying the position of each of at least one energy reflection location along a telecommunication wireline comprising the steps of:
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(a) generating a sinusoidal waveform having a frequency;
(b) coupling the sinusoidal waveform generated in step (a) to a measurement location of said telecommunication wireline;
(c) measuring the signal level at said measuring location of said telecommunication wireline to derive response data associated with said frequency;
(d) repeating steps (a)-(c) for each of a plurality of respectively different frequencies in addition to said frequency, so as to derive a set of response data associated with said plurality of respectively different frequencies; and
(e) performing frequency domain reflectometry (FDR) processing of response data associated with said frequency and said set of response data associated with said plurality of respectively different frequencies in a manner that is effective to determine the distance between said measurement location and said position of said at least one energy reflection location along said telecommunication wireline; and
whereinStep (d) includes compensating said response data associated with said frequency and said set of response data associated with said plurality of respectively different frequencies for loss through said telecommunication wireline, weighting samples of said said response data associated with said frequency and said set of response data associated with said plurality of respectively different frequencies to excise any DC level therein and to remove discontinuities between start and end values, and applying a loss compensation function to said weighted samples so as to compensate the frequency response characteristic of said wireline for loss over distance and frequency. - View Dependent Claims (19, 20, 21, 22, 23)
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Specification