Abstract: Hybrid echo canceller controllers are described herein. By way of example, a system for controlling an echo canceller can include a signal indicator and an echo canceller controller. The signal indicator can be configured to indicate periods of near-end signal and to indicate periods of echo only with echo-path change in the corrupted signal based at least in part on cross-correlation between two signals associated with the echo canceller. The echo canceller controller can be configured to control the echo canceller according to indications from the signal indicator.

Abstract: An echo canceler uses an adaptive filter to remove an echo of an incoming far-end signal from an outgoing near-end signal in the presence of ambient noise, updating the filter coefficients while the far-end signal is active and the near-end signal is inactive. The near-end and far-end signals are also sampled to obtain data vectors, which are averaged to generate simulated near-end and far-end signals, from which substitute filter coefficients are calculated and updated while the far-end signal is silent, the substitute filter coefficients being used when the far-end signal becomes active again. The number of data vectors averaged is varied according to the ratio of echo power to ambient near-end noise power, or according to the echo attenuation ratio, thereby speeding up convergence of the filter coefficients. Data sampled while the near-end and far-end signals are both active are excluded from the updating process.

Abstract: An echo canceler has an adaptive filter that generates an echo replica signal from a far-end signal. The filter coefficients of the adaptive filter are updated according to a residual error signal, which is obtained by subtracting the echo replica signal from a near-end signal to cancel echo. A background noise estimator estimates the near-end background noise power level from the residual error signal. A step size calculator uses the estimated near-end background noise power in determining the step size of the adaptive updating of the filter coefficients. When the estimated near-end background noise level is high, a small step size is used, which improves echo cancellation under these conditions. When the estimated near-end background noise level is low, a larger step size is used to permit rapid convergence of the filter coefficients.

Abstract: In one embodiment, a method for discriminating between a machine generated multi-tone signal and a simulated voice multi-tone signal is provided. The method may comprise comparing output profiles generated from sampled outputs of a plurality of filters. The plurality of filters may have a single input sample stream applied to them and each filter may be preset at a measured multi-tone frequency associated with an identified prospective multi-tone signal. Based on the comparison of the output profiles, an inequality degree between the output profiles is generated and compared to an inequality threshold, thereby to determine whether the input sample stream comprises a machine generated multi-tone signal.

Abstract: In one embodiment, a method for providing voice quality assurance is provided. The method determines voice information for an end point in a voice communication system. The voice information may be from an ingress microphone. The method determines if the voice quality is considered degraded based on an analysis of the voice information. For example, the voice information may indicate that it is distorted, too loud, too soft, is subject to an external noise, etc. Feedback information is determined if the voice quality is considered degraded where the feedback information designed to improve voice quality at an ingress point for a user speaking. The feedback information is then outputted at the end point to the user using the end point.

Abstract: An Ethernet extension device is provided for metro or last mile Ethernet service via twisted pairs as opposed to fiber optics. The Ethernet extension device is implemented as a plug-in extension for existing infrastructure (e.g., in a standard electrical wall box or Type-200™ Mechanics card) that employs lighting and power cross protection required by the telephone companies for Ethernet connectivity to the telephone network (e.g., for connection between a user's building and a telephone company building over existing outdoor telephone cables).