METHOD AND SYSTEM FOR PREESTIMATING MAXIMUM BANDWIDTH OF SUBSCRIBER LINE IN DIGITAL SUBSCRIBER LOOP

摘要

A method and a device for preestimating the maximum bandwidth of a subscriber line in a digital subscriber loop. The method comprises: obtaining independent crosstalk noise according to the line length of the measured subscriber line, the line transfer equation, and the power spectral density of each frequency signal in the band of a Digital Subscriber Loop(DSL) of the other subscriber lines in the line pair where the measured subscriber line is located; obtaining a total crosstalk noise by time domain superposition; according to the DSL band adopted by the measured subscriber line, selecting the total crosstalk noise and line attenuation subjected by each frequency signal in this band; obtaining the signal-to-noise ratio of each frequency signal in this band using the power spectral density of each frequency signal in this band; and obtaining the maximum bandwidth according to the frequency domain form of the Shannon theorem. The solution can exactly preestimate the maximum bandwidth of the subscriber line before the DSL services are actually launched.