Systems and methods for characterizing transmission lines using broadband signals in a multi-carrier DSL environment

• US 8,208,519 B2
• Filed: 04/08/2010
• Issued: 06/26/2012
• Est. Priority Date: 08/10/2000
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Aware Incorporated (Crowley Holdings Preferred LLC)
• Inventors: Belge, Murat, Tzannes, Michael A., Padir, Halil
• Primary Examiner(s): Odom, Curtis
• Application Number:
  US12/756,841
• Publication Number:
  US 20100195708A1
• Time in Patent Office: 810 Days
• Field of Search: 375219-222, 375/224
• US Class Current: 375/222
• CPC Class Codes: H04B 3/46 Monitoring; Testing
• CPC Class Codes: H04B 3/487 Testing crosstalk effects
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/24 Testing correct operation
• CPC Class Codes: H04L 1/245 by using the properties of transmission codes
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04M 3/2209 for lines also used for data transmission
• CPC Class Codes: H04M 3/2227 Quality of service monitoring
• CPC Class Codes: H04M 3/306 for frequencies above the voice frequency, e.g. xDSL line qualification test methods, test equipment and test arrangements for subscriber lines using xDSL modems H04M3/304; systems modifying transmission characteristics according to link quality H04L1/0001; monitoring and/or testing of line transmission systems H04B3/46
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Using DSL modems as data collectors, the modems processes the data to, for example, allow easier interpretation of the line characteristics. In particular, the modems postprocess the data including calibration, filter compensation, determination of the SNR medley from the bits and gains tables and rate conversion. The interpretation process uses the postprocessed data and determines loop characterization, interferer detection, a data reduction estimation and a data rate estimation. The outputs of these determinations least allow for the characterization of the line conditions between the two modems.

Claims

1. A multicarrier communications line characterization system comprising:

a data postprocessing and interpretation module capable of determining characteristics of a communication line, wherein the data postprocessing and interpretation module is capable of receiving raw data from a remotely located multicarrier modem having a data collection module, the data postprocessing and interpretation module capable of interpreting the raw data from the data collection module to determine characteristics of the communication line and estimating a physical structure of the communication line, the physical structure including a length of the communication line, wherein the raw data is measured by the multicarrier modem during a single-ended test of the communication line.

2. The system of claim 1, wherein the multicarrier line characterization system comprises the multicarrier modem having the data collection module capable of collecting raw data.

3. The system of claim 1, where the modem is one of a CO DSL modem or a CPE DSL modem.

4. The system of claim 1, wherein the single-ended test utilizes a reverb signal.

5. The system of claim 1, wherein the single-ended test utilizes a pre-defined signal and evaluates the echo waveform.

6. The system of claim 1, wherein a model of channel impulse response of the communication line is compared to an actual measured channel impulse response of the communication line.

7. The system of claim 1, wherein the single ended test is used to pre-qualify customer lines for DSL service.

8. The system of claim 1, wherein the single ended test is used to determine a type of DSL service to be ordered.

9. The system of claim 1, wherein the physical structure of the loop comprises a length or location of a bridged tap.

10. The system of claim 1, wherein one or more impedance discontinuities on the communication line are detected wherein the one or more impedance discontinuities are from at least one of bridged taps, an open ended loop or load coils.

11. The system of claim 1, wherein the estimated value of the length of the communication line is declared.

12. The system of claim 1, wherein the estimated value of the length of a bridged tap on the communication line is declared.

13. The system of claim 1, further wherein raw data is collected in the remotely located multicarrier modem.

14. A communication line characterization method for determining characteristics of a communication line, comprising:

receiving raw data from a remotely located multicarrier modem with a data collection module;

interpreting the raw data received from the data collection module to determine characteristics of the communication line;

estimating the physical structure of the communication line, the physical structure including the length of the communication line,

wherein the raw data is measured by the multicarrier modem during a single-ended test of the communication line.

15. The method of claim 14, wherein the modem is one of a CO DSL modem or a CPE DSL modem.

16. The method of claim 14, wherein the single-ended test utilizes a reverb signal.

17. The method of claim 14, wherein the single-ended test utilizes a pre-defined signal and evaluates the echo waveform.

18. The method of claim 14, wherein a model of channel impulse response of the communication line is compared to an actual measured channel impulse response of the communication line.

19. The method of claim 14, wherein the single ended test is used to pre-qualify customer lines for DSL service.

20. The method of claim 14, wherein the single ended test is used to determine a type of DSL service to be ordered.

21. The method of claim 14, wherein the physical structure of the loop comprises a length or location of a bridged tap.

22. The method of claim 14, wherein one or more impedance discontinuities on the communication line are detected and wherein the one or more impedance discontinuities are from at least one of bridged taps, an open ended loop or load coils.

23. The method of claim 14, wherein the estimated value of the length of the communication line is declared.

24. The method of claim 14, wherein the estimated value of the length of a bridged tap on the communication line is declared.

25. The method of claim 14, further comprising collecting raw data in the remotely located multicarrier modem.