Title:
METHOD AND APPARATUS FOR QUALIFYING LOOPS FOR DATA SERVICES
Document Type and Number:
WIPO Patent Application WO/2000/027134
Kind Code:
A2
Abstract:
A method and automatic test system for determining qualification of a twisted pair transmission line to propagate data signals. The method includes measuring phase imbalance in the twisted pair transmission line. The phase imbalance is determined by resistance imbalance in the twisted pair transmission line. The resistance imbalance is determined by applying a common mode voltage to the twisted pair transmission line; and determining phase imbalance in the twisted pair in response to the applied common mode voltage. The method includes applying a common mode voltage to the twisted pair transmission line; determining phase imbalance in the twisted pair in response to the applied common mode voltage; detecting a peak in the determined phase imbalance; determining a frequency of the detected peak; determining line qualification in accordance with the determined frequency. Methods are provided using series resistive imbalance and phase measurements to discover the type of imbalance existing on a twisted pair transmission line which is unable to support data transmissions. Methods are provided using series resistive imbalance and phase measurements to determine where an imbalance occurs as well as the magnitude of the imbalance.
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Inventors:
FAULKNER ROGER
SCHMIDT KURT E
ZHANG YUN
SCHMIDT KURT E
ZHANG YUN
Application Number:
PCT/US1999/024832
Publication Date:
May 11, 2000
Filing Date:
October 25, 1999
Export Citation:
Assignee:
TERADYNE INC (US)
International Classes:
H04B3/46; H04M1/24; H04M3/08; H04M3/22; H04M3/30; H04Q1/20; H04Q; (IPC1-7): H04Q/
Foreign References:
| US5699402A | 1997-12-16 | |||
| US5864602A | 1999-01-26 |
Other References:
ROEHRKASTEN W: "MESSUNG VON XDSL-PARAMETERN" NACHRICHTENTECHNIK ELEKTRONIK,DE,VEB VERLAG TECHNIK. BERLIN, vol. 48, no. 2, 1 March 1998 (1998-03-01), pages 20-21, XP000752845 ISSN: 0323-4657
ZIEMANN, PETER: "ADSL line qualification tests" [Online] , WANDEL & GOLTERMANN XP002148948 Retrieved from the Internet: [retrieved on 2000-09-28] page 1-2
BACKER, TODD; PUCKETT, RICK: "Telephone Access Network Measurements" 1998 , TEKTRONIX XP002148949 paragraph [0017]
"IEEE Std 743-1995 IEEE Standard Equipment Requirements and Measurement Techniques for Analog Transmission Parameters for Telecommunications" 1996 , IEEE , US XP002148950 paragraph [10.6]
ZIEMANN, PETER: "ADSL line qualification tests" [Online] , WANDEL & GOLTERMANN XP002148948 Retrieved from the Internet:
BACKER, TODD; PUCKETT, RICK: "Telephone Access Network Measurements" 1998 , TEKTRONIX XP002148949 paragraph [0017]
"IEEE Std 743-1995 IEEE Standard Equipment Requirements and Measurement Techniques for Analog Transmission Parameters for Telecommunications" 1996 , IEEE , US XP002148950 paragraph [10.6]
Attorney, Agent or Firm:
Walsh, Edmund J. (321 Harrison Avenue Boston, MA, US)
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Claims:
What is claimed is:
| 1. | A method for qualifying a transmission line to propagate data signals comprising: measuring phase imbalance in the transmission line at a terminating end of the transmission line. |
| 2. | A method for qualifying a transmission line to propagate data signals, comprising: measuring resistance imbalance in the transmission line from a terminating end of the transmission line. |
| 3. | A method for qualifying a transmission line to propagate data signals, comprising: applying a common mode voltage to a terminating end of the transmission line; and, determining phase imbalance in the line in response to the applied common mode voltage. |
| 4. | A method for analyzing a transmission line comprising: applying a common mode voltage having a frequency changing over a range of frequencies into the transmission line; determining phase of signals produced on each wire of the transmission line, in response to the applied voltage, relative to the applied voltage; detecting a peak in the determined phase; determining a frequency of the detected peak. |
| 5. | A method for qualifying a transmission line to propagate data signals, comprising: applying a common mode voltage having a frequency changing over a range of frequencies into the transmission line; determining phase imbalance in response to the applied common mode voltage; detecting a peak in the determined phase imbalance; determining a frequency of the detected peak. |
| 6. | A method for automatically qualifying a plurality of transmission lines, comprising: feeding signals from a controller to a switch connected to termination ends of the transmission lines; coupling test signals to the transmission lines through the switch selectively in accordance with control signal fed to the switch; detecting resistance imbalance between each of the legs in a selected one of the transmission lines. |
| 7. | A system for automatically qualifying a plurality of transmission lines, such system comprising: a switch coupled to terminating ends of the plurality of a transmission lines; a controller for feeding signals to the switch; a measurement unit coupled to the switch and the controller, such measurement unit being adapted to feed test signals from the measurement unit to a selected one of the transmission lines through the switch, such one of the transmission lines being selected in accordance with a control signal fed to the switch by the controller, such measurement unit isolating resistance imbalance between each of a pair of lines in the selected one of the transmission lines in response to the feed test signals fed to such selected one of the transmission lines; and wherein the controller, in response to the isolated resistance imbalance, is adapted to determine qualification of the selected one of the transmission lines for data signals. |
| 8. | A method for analyzing a transmission line recited in claim 4 including: comparing the frequency of the detected peak in the determined phase with one or more reference frequencies. |
| 9. | A method for analyzing a transmission line recited in claim 4 including: determining, in response to the frequency comparison, whether a resistive imbalance is present on the transmission line. |
| 10. | A method for analyzing a transmission line recited in claim 4 including: determining, in response to the frequency comparison, a type of resistive imbalance present on the transmission line. |
| 11. | A method for analyzing a transmission line recited in claim 4 further including: determining, in response to the frequency comparison, presence of a capacitance imbalance on the transmission line. |
| 12. | A method for analyzing a transmission line recited in claim 4 further including: determining, in response to the frequency comparison, presence of an inductive imbalance on the transmission line. |
| 13. | A method for analyzing a transmission line recited in claim 10 further including: determining whether the resistive imbalance is series a series resistive imbalance. |
| 14. | A method of analyzing a transmission line recited in claim 13 further including: determining whether the resistive imbalance varies with time. |
| 15. | A method for analyzing a transmission line recited in claim 9 further including: computing admittance of the transmission line at varying frequencies; deriving capacitance of the transmission line from the computed admittance; dividing the derived capacitance of the transmission line by perunit length capacitance for type of transmission line under test to produce a quotient; location the position of the imbalance on the transmission line from the produced quotient. |
| 16. | A method for analyzing a transmission line recited in claim 9 further including: measuring the magnitude of the voltage on each one of the legs of the transmission line in response to the applied voltage; comparing the absolute value of the measured magnitude voltage and a detected frequency peak with a list of reference data; determining the location of the imbalance based on the comparison. |
| 17. | A method for analyzing a transmission line recited in claim 9 further including: comparing the frequency of a detected peak to a list of reference data; determining the magnitude of an imbalance on the line based on the comparison. |
| 18. | A method of analyzing a telephone line having at least a first leg and a second leg, the method comprising the steps of: a) applying test signals to the first leg and the second leg to determine, at a first frequency and a second frequency: i) the capacitance between the first leg and ground; and ii) the capacitance between the second leg and ground; b) determining that no resistive imbalance exists when: i) the difference between the capacitance between the first leg and ground measured at the first frequency and the second frequency is below a threshold; and ii) the difference between the capacitance between the second leg and ground measured at the first frequency and the second frequency is below a threshold. |
| 19. | The method of claim 18 additionally comprising the step of identifying an imbalance when the difference between the capacitance between one of the legs and ground measured at the first frequency and the second frequency exceeds a threshold. |
| 20. | The method of claim 18 additionally comprising the step of identifying the leg containing the imbalance as being the leg in which the difference between the capacitance between that leg and ground measured at the first frequency and the second frequency exceeds the threshold. |
Description:
INTERNATIONALSEARCHREPORT | Int onaiApplicationNo PCT/US99/24832 C.(Continuation)DOCUMENTSCONSIDEREDTOBERELEVANT CategoryCitationofdocument,withindication,whereappropriate,o
ftherelevantpassagesRelevanttoclaimNo. AZIEMANN,PETER:"ADSLlinequalification1-7,18 tests"'Online!,WANDEL&GOLTERMANN XP002148948 RetrievedfromtheInternet:<URL: http://www.wg.com/appnotes/adsltest.html> 'retrievedon2000-09-28! page1-2 ABACKER,TODD;PUCKETT,RICK:"Telephone1-7,18 AccessNetworkMeasurements" 1998,TEKTRONIXXP002148949 paragraph'0017! A"IEEEStd743-1995IEEEStandard1-7,18 EquipmentRequirementsandMeasurement TechniquesforAnalogTransmission ParametersforTelecommunications" 1996,IEEE,USXP002148950 paragraph'10.6! P,AUS5864602A(NEEDLEJACK)18 26January1999(1999-01-26) abstract 1 INTERNATIONALSEARCHREPORT ) nal ApplicationNo tnfonnationonpatent family members PCT/US99/24832 PatentdocumentPublicationPatentfamily Publication citedinsearchreportdatemember(s)date US5699402A16-12-1997BR9509197A 21-10-1997 CZ9700891A 13-08-1997 EP0783813A 16-07-1997 SK39797A 05-11-1997 WO9610890A 11-04-1996 US6026145A 15-02-2000 US5870451A 09-02-1999 US5864602A26-01-1999US5978449A 02-11-1999
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