Patent ID: 6757834
Filing Date: 2004-06-29
Classification: H03G,H04L

Abstract:
A method of minimizing power dissipation in a line driver in a central office for driving a DSL connection of unknown length to a network terminal with a predetermined maximum constellation size, characterized by the following steps during a training sequence initiated by the central office to set up the connection:a) at the central office, supplying the line driver with a predetermined supply voltage, and b) transferring data with a predetermined power spectral density in all available channels to the network terminal, c) at the network terminal, measuring signal-to-noise ratio of each channel, and d) transferring information to the central office about channels having signal-to-noise ratios that enable transfer of data, e) at the central office, reducing the power spectral density to a lowest possible value that enables transfer of data in all channels having signal-to-noise ratios above a predetermined threshold as set by the maximum constellation size, f) calculating a sum of power to be transmitted in said channels having signal-to-noise ratios above the predetermined threshold, g) converting said sum into a corresponding line driver output voltage, and h) reducing the line driver supply voltage in correspondence thereto.