US5821760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring near-end cross-talk in patch cords
Assignee: Fluke Corp
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Filing: 1996-07-31
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Granted: 1998-10-13
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Expires: 2016-07-31
Abstract
Abstract A pulse-based local area network (LAN) cable test instrument provides a measurement of the cross-talk characteristic of a LAN patch cord as a function of frequency in order to evaluate its relative performance and workmanship of assembly. A LAN cable test instrument applies a test signal in the form of narrow pulses to a selected transmission line of a LAN patch cord while the cross-talk response induced in another transmission line in the same LAN patch cord is measured and stored as a time record in digital memory. The near-end and far-end pulse responses are separated in the time record, leaving only the near-end pulse response. The LAN cable test instrument analyzes the near-end pulse response by performing a discrete Fourier transform on the time record to provide cross-talk versus frequency information. The same test may then be performed on the far-end end of the patch cord to obtain a complete test of the quality of workmanship at both ends of the patch cable.
Inventors
- 👤 Henriecus Koeman
- 👤 Jeffrey S. Bottman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:41
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/08; H; H04; H04B; H04B3/00; H04B3/02; H04B3/46
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
141 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord, comprising: (a) first and second instrument connectors coupled to receive a near-end connector and a far-end connector of said patch cord; (b) first and second pulse generators for generating a first and second set of stimulus pulses in one of a selected pair of transmission lines in said patch cord; (c) first and second digitizers coupled to said near-end and far-end connectors for receiving cross-talk signals induced by said stimulus pulses in another of said selected pair of transmission lines to produce near-end and far-end pulse-response time records of said cross-talk signals; and (d) a microprocessor coupled to said digitizer for receiving said near-end and far-end pulse response time records, separating said near-end cross-talk response from said far-end cross-talk response, and calculating a near-end frequency domain representation.
Claim 2
Dependent Claim
141 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord, comprising: (a) first and second instrument connectors coupled to receive a near-end connector and a far-end connector of said patch cord; (b) first and second pulse generators for generating a first and second set of stimulus pulses in one of a selected pair of transmission lines in said patch cord; (c) first and second digitizers coupled to said near-end and far-end connectors for receiving cross-talk signals induced by said stimulus pulses in another of said selected pair of transmission lines to produce near-end and far-end pulse-response time records of said cross-talk signals; and (d) a microprocessor coupled to said digitizer for receiving said near-end and far-end pulse response time records, separating said near-end cross-talk response from said far-end cross-talk response, and calculating a near-end frequency domain representation.
Claim 3
Dependent Claim
35 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 1 wherein said near-end cross-talk response is separated from said far-end cross-talk response according to a near-end window.
Claim 4
Dependent Claim
36 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 2 wherein said near-end window is selected to exclude areas of said patch cord having said far-end cross-talk response.
Claim 5
Dependent Claim
29 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 1 wherein said near-end frequency domain representation is normalized against calibration data.
Claim 6
Dependent Claim
43 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 4 wherein said microprocessor generates a first decision that is one of pass and fail by comparing said near-end frequency domain representation to a limit line.
Claim 7
Dependent Claim
160 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 5 further comprising a remote unit, said remote unit comprising: (a) said second instrument connector coupled to receive said far-end connector of said patch cord; (b) said second pulse generator coupled to said second instrument connector for generating said second set of stimulus pulses in said one of a selected pair of transmission lines in said patch cord at a time different from the generating of said first set of stimulus pulses; and (c) said second digitizer coupled to said second instrument connector for receiving a second set of cross-talk signals from said another of said selected pair of transmission lines and producing said far-end pulse-response time record of said second set of cross-talk signals wherein said far-end pulse-response time record is coupled to said microprocessor for separating said far-end cross-talk response from said near-end cross-talk and calculating a far-end frequency domain representation.
Claim 8
Dependent Claim
29 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 6 wherein said far-end frequency domain representation is normalized against calibration data.
Claim 9
Dependent Claim
43 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 7 wherein said microprocessor generates a second decision that is one of pass and fail by comparing said far-end frequency domain representation against a limit line.
Claim 10
Dependent Claim
34 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 8 further comprising a display coupled to said microprocessor for visually displaying said first and second decisions.
Claim 11
Dependent Claim
35 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 6 wherein said far-end cross-talk response is separated from said near-end cross-talk response according to a far-end window.
Claim 12
Dependent Claim
36 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 10 wherein said far-end window is selected to exclude areas of said patch cord having said near-end cross-talk response.
Claim 13
Dependent Claim
37 words
A test instrument for measuring near-end and far-end cross-talk response in a patch cord according to claim 1 wherein said instrument connectors are prequalified to produce predetermined maximum levels of cross-talk within a set of tolerance values.
Claim 14
Independent Claim
108 words
A method for measuring near-end and far-end cross-talk response in a patch cord, comprising: (a) generating stimulus pulses in one of a pair of transmission lines at a near-end and a far-end of said patch cord; (b) digitizing cross-talk signals induced in another of said pair of transmission lines by said stimulus pulses at said near-end and said far-end of said patch cord to produce near-end and far-end pulse response time records; (c) separating said near-end cross-talk response from a far-end cross-talk response in said near-end and far-end pulse response time records; and (d) calculating near-end and far-end frequency domain representations of said near-end pulse response time records.
Claim 15
Independent Claim
108 words
A method for measuring near-end and far-end cross-talk response in a patch cord, comprising: (a) generating stimulus pulses in one of a pair of transmission lines at a near-end and a far-end of said patch cord; (b) digitizing cross-talk signals induced in another of said pair of transmission lines by said stimulus pulses at said near-end and said far-end of said patch cord to produce near-end and far-end pulse response time records; (c) separating said near-end cross-talk response from a far-end cross-talk response in said near-end and far-end pulse response time records; and (d) calculating near-end and far-end frequency domain representations of said near-end pulse response time records.
Claim 16
Dependent Claim
34 words
A method for measuring near-end and far-end cross-talk response in a patch cord according to claim 13 further comprising separating said near-end cross-talk response from said far-end cross-talk response according to a near-end window.
Claim 17
Dependent Claim
35 words
A method for measuring near-end and far-end cross-talk response in a patch cord according to claim 14 further comprising selecting said near-end window to exclude areas of said patch cord having a far-end cross-talk response.
Claim 18
Dependent Claim
34 words
A method for measuring near-end and far-end cross-talk response in a patch cord according to claim 13 further comprising separating said far-end cross-talk response from said near-end cross-talk response according to a far-end window.
Claim 19
Dependent Claim
35 words
A method for measuring near-end and far-end cross-talk response in a patch cord according to claim 16 further comprising selecting said far-end window to exclude areas of said patch cord having said near-end cross-talk response.
Claim 20
Dependent Claim
46 words
A method for measuring near-end and far-end cross-talk response in a patch cord according to claim 13 further comprising generating a decision that is one of pass and fail by comparing said near-end frequency domain representation and said far-end frequency domain representation against a limit line.
Claim 21
Dependent Claim
23 words
A method for measuring near-end and far-end cross-talk response in a patch cord according to claim 18 further comprising visually displaying said decision.
Claim 22
Independent Claim
170 words
A method for testing cross-talk performance of a patch cord, comprising: (a) generating stimulus pulses in one of a pair of transmission lines at a near-end of said patch cord; (b) digitizing cross-talk signals induced in another of said pair of transmission lines by said stimulus pulses at said near-end of said patch cord to produce a near-end pulse response time record; (c) generating said stimulus pulses in said one of a pair of transmission lines at a far-end of said patch cord; (d) digitizing cross-talk signals induced in said another of said pair of transmission lines by said stimulus pulses at said far-end of said patch cord to produce a far-end pulse response time record; (e) separating said near-end cross-talk response from a far-end cross-talk response in said near-end pulse response time record and in said far-end pulse response time record; and (f) calculating a near-end frequency domain representation of said near-end pulse response time record and a far-end frequency domain representation of said far-end pulse response time record.
Claim 23
Independent Claim
170 words
A method for testing cross-talk performance of a patch cord, comprising: (a) generating stimulus pulses in one of a pair of transmission lines at a near-end of said patch cord; (b) digitizing cross-talk signals induced in another of said pair of transmission lines by said stimulus pulses at said near-end of said patch cord to produce a near-end pulse response time record; (c) generating said stimulus pulses in said one of a pair of transmission lines at a far-end of said patch cord; (d) digitizing cross-talk signals induced in said another of said pair of transmission lines by said stimulus pulses at said far-end of said patch cord to produce a far-end pulse response time record; (e) separating said near-end cross-talk response from a far-end cross-talk response in said near-end pulse response time record and in said far-end pulse response time record; and (f) calculating a near-end frequency domain representation of said near-end pulse response time record and a far-end frequency domain representation of said far-end pulse response time record.
Claim 24
Dependent Claim
48 words
A method for testing cross-talk performance of a patch cord according to claim 20 further comprising: separating said far-end cross-talk response from said near-end cross-talk response according to a far-end window; and further separating said near-end cross-talk response from said far-end cross-talk response according to a near-end window.
Claim 25
Dependent Claim
50 words
A method for testing cross-talk performance of a patch cord according to claim 21 further comprising: selecting said far-end window to exclude areas of said patch cord having said near-end cross-talk response; and further selecting said near-end window to exclude areas of said patch cord having said far-end cross-talk response.
Claim 26
Dependent Claim
31 words
A method for testing cross-talk performance of a patch cord according to claim 20 wherein said near-end frequency domain representation and said far-end frequency domain representation are normalized against calibration data.
Claim 27
Dependent Claim
43 words
A method for testing cross-talk performance of a patch cord according to claim 20 further comprising generating a decision that is one of pass and fail by comparing said near-end frequency domain representation and said far-end frequency domain representation against a limit line.
Claim 28
Dependent Claim
20 words
A method for testing cross-talk performance of a patch cord according to claim 24 further comprising visually displaying said decision.
References Cited (Backward Citations)
US4524321A
Cited
US5063351A
Cited
US5185735A
Cited
US5539321A
Cited
US5502391A
Cited
US5570029A
Cited
US5559427A
Cited
US5629628A
Cited
US5548222A
Cited
US5530367A
Cited
US5532603A
Cited
US5698985A
Cited
US5731706A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-12 | 2002-04-13 | 2002-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-12 | 2006-04-13 | 2006-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-12 | 2010-04-13 | 2010-10-13 | $7700.00 | Window Closed / Lapsed |