Analog echo cancellation with Digital-to-Analog Converter (DAC) noise suppression may be provided. First, a test signal may be sent through an echo cancellation pathway during a downstream silence period and an upstream silence period. The echo cancellation pathway may comprise an electronic element. Next, a loopback response signal may be received in response to sending the test signal through the echo cancellation pathway. Then a channel response model may be created that characterizes a channel response of the loopback response signal and a non-linear model may be created that characterizes a non-linearity of the electronic element. Next, for a downstream signal, a non-linear component may be generated based on the created non-linear model. The generated non-linear component may be convolved with the created channel response model. The convolved non-linear component may then be subtracted from an upstream signal.

Analog echo cancellation with Digital-to-Analog Converter (DAC) noise suppression may be provided. First, a test signal may be sent through an echo cancelation pathway during a downstream silence period and an upstream silence period. The echo cancelation pathway may comprise an electronic element. Next, a loopback response signal may be received in response to sending the test signal through the echo cancelation pathway. Then a channel response model may be created that characterizes a channel response of the loopback response signal and a non-linear model may be created that characterizes a non-linearity of the electronic element. Next, for a downstream signal, a non-linear component may be generated based on the created non-linear model. The generated non-linear component may be convolved with the created channel response model. The convolved non-linear component may then be subtracted from an upstream signal.

A cable modem comprises transceiver circuitry and echo cancellation training circuitry. The transceiver circuitry may be operable to transmit and receive signals on a full-duplex Data Over Cable System Interface Specification (DOCSIS) network. The echo cancellation training circuitry may be operable to: determine an echo cancellation training group to which the electronic communication device belongs; determine one or more training periods during which the echo cancellation training group is permitted to transmit training signals; and transmit an echo cancellation training signal during the determined training one or more periods and use the transmitted training signal to train echo cancellation circuitry of the cable modem.

A method for initialization of a group of customer premises equipment devices (CPEs) during a training that registers capabilities of the CPEs is disclosed, wherein at least one CPE registers late to the training and cannot be registered. The method includes determining capabilities of the CPEs during a joining phase of the training, wherein it is determined whether a CPE device is capable of employing vectoring, and placing in a hold status the at least one CPE that registers late by keeping a line active that is coupled to the at least one CPE. The method further includes providing another joining phase after the joining phase to register the at least one CPE that registers late.

A method, system, and apparatus for calibration for cable modem (CM) echo cancellation (EC) training in full duplex (FDX) coaxial networks is provided. A CM receives a current resource block assignment message (RBA) from a cable modem termination system (CMTS), and determines if designated channels available for assignment as downstream (DS) channels or upstream (US) channels have changed assignment values from a previously received RBA, and if EC training has been performed on the designated channels for the current RBA. If the designated channels have changed assignment values and EC training has not been performed on the designated channels for the current RBA, the CM performs EC training on the designated channels for the current RBA.

An echo cancellation training method in a cable modern is provided, comprising receiving an echo cancellation service ID (EC SID) assigned for echo cancellation training, the cable modem receiving the EC SID from a cable head end in an information element (IE) in a map (MAP or P-MAP) defining a time and frequency of upstream transmission opportunities for the cable modem, the EC SID establishing when the cable modem may perform the echo cancellation training in a downstream channel allocated to the cable modem, transmitting an echo cancellation test signal upstream to the cable head end via an upstream channel allocated to the cable modem and in a time slot specified by the received EC SID in the map, and measuring noise in one or more downstream channels allocated to the cable modem, with the noise resulting from the transmission of the echo cancellation test signal on the upstream channel.

Various aspects of this disclosure describe detecting a signal and measuring power with a multi-band filter. Examples include a signal detection and power measurement module in a receiver capable of detecting a training signal and calculating a reliable power measurement in the presence of narrowband interference. A received signal is filtered by a multi-band filter comprising a plurality of sub-band filters. For instance, sub-band filters may be bandpass filters with non-overlapping pass-bands. A training signal is detected by comparing powers of each of the outputs of the sub-band filters to a plurality of thresholds. For example, each sub-band may be assigned a different threshold value. Responsive to detecting a training signal, a power measurement is determined from at least one sub-band filter output. A gain is set based on the determined power measurement, and applied in the receiver.

A novel procedure is described which provides a method for initialization of a group of CPE devices (short: CPEs) during a training that in part registers capabilities of the CPEs, wherein at least one CPE registers late to the training and thus cannot be registered. In accordance with the example described herein, the method comprises: determining capabilities of the CPEs during a Joining Phase of the training, wherein it is determined whether a CPE device is capable of employing vectoring. The method further comprises placing in a hold status the at least one CPE that registers late by keeping a line active that is coupled to the at least one CPE. Another Joining Phase is provided after the Joining Phase in order to register the at least one CPE which has registered late.

Facilitating echo cancellation within communication networks is contemplated, such as but not necessarily limited to facilitating echo cancellation within full-duplex (FDX) communication networks. The echo cancellation may optionally be performed with an echo canceller included as part of or otherwise associated with an FDX node used to facilitate interfacing signaling between a digital domain and an analog domain of a FDX or other communication network.

A system for enhancing tonal quality for ringback signals in a telecommunications network by adjusting audio processing during an alerting interval of a telecommunications session (e.g. during a telephone call). The system may be embodied in a telecommunications switching device and include a ringback manager process that provides the ability to adjust audio processing (e.g., by signaling to in-path equipment) which enhances the tonal quality of the ringback signal. As an example, a telephone system (e.g. equipment associated with establishment and operation of telephone communications sessions) can disable or attenuate operation of voice quality enhancement processing such as echo cancellation, noise reduction, adaptive level control, and the like, during the ringback or alerting interval or period of a telephone call so that the ringback tone provided to the calling party is not distorted by such processing.