Abstract: The present invention involves a transmission of a known signal over a line intended for a digital subscriber line (xDSL) service, measurement of a resulting waveform received through the line and processing of the received signal to derive a set of eigenvalues characterizing the transfer function of the line. In the preferred embodiment, a transmitter applies a known test signal waveform to the transmission line. The test signal corresponds to a desired one of several available xDSL services. At the receiving end of the line, the output signal from the line is sampled, to capture a digitized sample waveform for the received signal. A computer processes the captured waveform to determine eigenvalues characterizing the transfer function of the line with respect to the one service. If the eignevalues for the line bear predetermined relationships to threshold values, indicating acceptable line transfer function for the desired xDSL service, then the invention certifies the tested line for use on that service.

Abstract: To eliminate problems caused by the use of batteries for back-up power in outside plant facilities of a communication network or the like, the batteries are replaced with flywheel reserve power systems, in accord with the invention. Specific applications of flywheel power systems include flywheel systems to supply power to the optical terminal of a digital loop carrier type system, for a telephone network. Other applications relate to flywheel systems to supply power to optical network units (ONUs) in fiber to the curb or fiber to the home type communication networks. In the preferred embodiments, the flywheel power systems include intelligent components for monitoring and controlling operations of the power systems. Communication links are provided, to enable the monitoring and control components to report status to and receive control instructions from a centralized network control or management center.