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US 6,445,773 B1Granted
DMT test method for determining ADSL capability of cables
AssigneeConsultronics Limited
InventorsRonald Y. R. Liang, Robert Layton
Life of this patent
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AssigneeConsultronics Limited
InventorsRonald Y. R. Liang, Robert Layton
Estimating the term…
A DMT (Discrete Multi-Tone) test method is provided. The test method is employed by two test devices to estimate the theoretical and practical data rates of a cable under test for a pair of target ADSL (Asymmetric Digital Subscriber Line) DMT modems. The present DMT test can also be used to analyze the cause of, or to predict a problem, whereby a pair of ADSL DMT modems could fail to synchronize. The method includes (a) synchronizing two devices at lower frequencies; (b) measuring the frequency characteristics of the cable with test signals; (c) measuring the cable noise and interference for every sub-channel of the ADSL bandwidth; (d) determining the theoretical and practical data rates for every sub-channel, based on the measured frequency characteristics and noise characteristics, as well as modem parameters selected by the user; (e) estimating the theoretical and practical data rates for the ADSL bandwidth based on the ADSL DMT standard selected by the user.
A method for performing a DMT test to determine cable data rates using two test devices, without employing ADSL modems, on a telephone cable or a local loop cable for ADSL application, whereby an available frequency bandwidth is divided into sub-channels, the method comprising the steps of:
The method of claim, wherein a time-domain or frequency-domain analysis method is used for detecting and receiving the synchronization signal.
Dependencies are inferred from the claim text.