Telephonic communications – Diagnostic testing – malfunction indication – or electrical... – Of trunk or long line
Reexamination Certificate
2002-04-23
2004-12-07
Tran, Quoc (Department: 2643)
Telephonic communications
Diagnostic testing, malfunction indication, or electrical...
Of trunk or long line
C379S001010, C379S001040, C379S022000, C379S024000, C379S027030, C379S028000
Reexamination Certificate
active
06829330
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to determination of transmission line characteristics. In particular, this invention relates to systems and methods for loop characterization from double-ended measurements by estimating the loop length and the bridged tap lengths of a subscriber loop with a model based least-squares approach using a differential evolution algorithm.
2. Description of Related Art
The collection and exchange of diagnostic and test information between transceivers in a telecommunications environment is an important part of a telecommunications, such as an ADSL, deployment. In cases where the transceiver connection is not performing as expected, for example, where the data rate is low, where there are many bit errors, or the like, it is necessary to collect diagnostic and test information from the remote transceiver. This is performed by dispatching a technician to the remote site, e.g., a truck roll, which is time consuming and expensive.
In DSL technology, communications over a local subscriber loop between a central office and a subscriber premises is accomplished by modulating the data to be transmitted onto a multiplicity of discrete frequency carriers which are summed together and then transmitted over the subscriber loop. Individually, the carriers form discrete, non-overlapping communication subchannels of limited bandwidth. Collectively, the carriers form what is effectively a broadband communications channel. At the receiver end, the carriers are demodulated and the data recovered.
DSL systems experience disturbances from other data services on adjacent phone lines, such as, for example, ADSL, HDSL, ISDN, T1, or the like. These disturbances may commence after the subject ADSL service is already initiated and, since DSL for internet access is envisioned as an always-on service, the effect of these disturbances must be ameliorated by the subject ADSL transceiver.
SUMMARY OF THE INVENTION
Identifying, measuring and characterizing the condition of a transmission line is a key element of an ADSL deployment. In cases when the transceiver connection is not performing as expected, for example, the data rate is low, there are many bit errors, a data link is not possible, or the like, it is important to be able to identify the loop length and the existence, location and length of any bridged taps without having to send a technician to the remote modem site to run diagnostic tests.
This invention describes an exemplary system and method for estimating the loop length, the number of bridged taps and length of the bridged taps on a transmission line. The loop length, the number of bridge taps and the length of the bridged taps can be estimated by comparing a measured frequency domain channel impulse response of the transmission line to a model of a transmission line that is composed of multiple sections and multiple bridge taps. The diagnostic and test information describing the condition of the line can then be exchanged, for example, by two transceivers during a diagnostic link mode, or the like.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the embodiments.
REFERENCES:
patent: 5128619 (1992-07-01), Bjork et al.
patent: 5864602 (1999-01-01), Needle
patent: 6002671 (1999-12-01), Kahkoska et al.
patent: 6058162 (2000-05-01), Nelson et al.
patent: 6091713 (2000-07-01), Lechleider et al.
patent: 6177801 (2001-01-01), Chong
patent: 6205202 (2001-03-01), Yoshida et al.
patent: 6215855 (2001-04-01), Schneider
patent: 6292468 (2001-09-01), Sanderson
patent: 6292539 (2001-09-01), Eichen et al.
patent: 6487276 (2002-11-01), Rosen et al.
patent: 6516049 (2003-02-01), Heidari et al.
patent: 6538451 (2003-03-01), Galli et al.
patent: 6553098 (2003-04-01), Harrison et al.
patent: 6584176 (2003-06-01), Murphree et al.
patent: 2001/0043647 (2001-11-01), Belge
patent: 1041731 (2000-10-01), None
patent: 2 303 032 (1997-02-01), None
patent: WO 97/01900 (1997-01-01), None
patent: WO 99/26375 (1999-05-01), None
patent: WO 00/64130 (2000-10-01), None
patent: WO 0101158 (2001-01-01), None
patent: WO 0152439 (2001-07-01), None
patent: WO 0213405 (2002-02-01), None
Lewis L. et al.: “Extending Trouble Ticket Systems To Fault Diagnostics” IEEE Network, Nov. 1993, pp. 44-51, XP 000575228.
Patrick Boets et al.: “The Modelling Aspect Of Transmission Line Networks” Proceedings Of The Instrumentation And Measurement Technology Conference, US, New York, IEEE, May 12, 1992, pp. 137-141, XP 000343913.
Marcos Tzannes “Draft New Recommendation G.996.1: Test Procedures For Digital Subscriber Line(DSL)Transceivers—For Approval”, Mar. 1992, 2 pages.
Ranier Storn et al. “Differential Evolution—A Simple And Efficient Adaptive Scheme For Global Optimization Over Continuous Spaces”, Mar. 1995, 11 pages.
International Search Report, Date of Mailing Mar. 14, 2003.
Rizzi, P. A., “Microwave Engineering”, Prentice-Hall, Englewood Cliffs, N.J., 1988, pp. 534-540.
Belge Murat
Storn Rainer
Aware Inc.
Miles & Stockbridge P.C.
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