Abstract: Embodiments of the invention provide methods for determining the characteristics of a local loop using the multi-carrier tones of a DSL activation process. For one embodiment, one or more sets of downstream multi-carrier tones of a digital subscriber line activation process are received at an extended voice-band modem and are capable of transmitting upstream multi-carrier tones of the digital subscriber line activation process over a local loop. The downstream carrier tones and the upstream carrier tones are folded into a first multi-tone signal and a second multi-tone signal, respectively, each having a plurality of component signals within the spectrum band of the extended voice-based modem. The total signal power of the first multi-tone signal is divided by the power of one of the plurality of component signals of the second multi-tone signal to determine a ratio value. The ratio value is used to determine a characteristic of the local loop.

Abstract: Embodiments of the invention provide methods and apparatuses to determine the characteristics of a local loop using the multi-tone line-probing signals of a standard voice-based modem. For one embodiment, the multi-tone, line-probing signals of a voice-band modem are transmitted over a local loop and received at a standard voice band modem. Discrete Fourier transform values are determined for each of two or more frequencies of the plurality of frequencies of the multi-tone signals. A set of discrete Fourier transform values corresponding to a set of high frequencies is summed to obtain a first value and a set of discrete Fourier transform values corresponding to a set of low frequencies is summed to obtain a second value. A power ratio is determined by dividing the first value by the second value. The power ratio is then used to determine a characteristic of the local loop.

Abstract: Embodiments of the invention provide methods and apparatuses to determine the characteristics of a local loop using the multi-tone line-probing signals of a standard voice-based modem. For one embodiment, the multi-tone, line-probing signals of a voice-band modem are transmitted over a local loop and received at a standard voice band modem. Discrete fourier transform values are determined for each of two or more frequencies of the plurality of frequencies of the multi-tone signals. A set of discrete fourier transform values corresponding to a set of high frequencies is summed to obtain a first value and a set of discrete fourier transform values corresponding to a set of low frequencies is summed to obtain a second value. A power ratio is determined by dividing the first value by the second value. The power ratio is then used to determine a characteristic of the local loop.