Patent ID: 8385510

Claim:
A method in a Digital Subscriber Line (DSL) system for estimating a transmission property of a telecommunications transmission line, the method comprising the steps of: making a first frequency domain reflectometry Single Ended Line Testing (SELT) measurement which comprises the steps of: sending a first signal to the line; receiving a resulting second signal from the line; and estimating a property of the line in dependence of a relationship between the first signal and the second signal, wherein the first SELT measurement is made in a first stop band and in accordance or substantially in accordance with a Power Spectral Density (PSD) mask by which the first signal is sent in the first stop band of a DSL band plan, the first signal having a PSD in accordance or substantially in accordance with the PSD mask associated with the band plan and applicable to a particular setting where the sending of the first signal takes place, making a second frequency domain reflectometry SELT measurement in a first pass band adjacent to the first stop band, the measurement comprising sending a second signal to the line; concatenating results of the first and second SELT measurements to form a single measurement result over a contiguous frequency range comprising the whole or at least parts of the frequency ranges of the first and second SELT measurements, wherein the first and second SELT measurements are made in an xTU-O or an xTU-R, and wherein the power of the second signal sent for the second SELT measurement is several orders of magnitude greater than the power of the first signal sent for the first SELT measurement.