Abstract: A communication system comprises a plurality of line cards having transceivers coupled to a plurality of subscriber lines. Each line card has at least one active transceiver within the same vectoring group, and each line card also has vector logic capable of cancelling crosstalk induced by an active transceiver that is a member of the vectoring group. Further, the line cards are coupled to one another via a ring connection across which vectoring information is passed from one line card to the next. In the event of a failure of one of the line cards, the failed card is bypassed by the vectoring stream so that the operational line cards can continue crosstalk vectoring operations despite such failure.

Abstract: A communication system comprises a plurality of line cards having transceivers coupled to a plurality of subscriber lines. Each line card has at least one transceiver within the same vectoring group, and each line card also has vector logic capable of cancelling crosstalk induced by a tone communicated by any member of the vector group. Further, the line cards are coupled to one another via a data connection across which a vectoring stream carrying vectoring information from one line card to the next. The bandwidth of the vectoring stream is reduced by dynamically adjusting time slots of the vectoring stream based on bit loading for the communicated tones.

Abstract: A communication system comprises a plurality of line cards having transceivers coupled to a plurality of subscriber lines. Each line card has at least one active transceiver within the same vectoring group, and each line card also has vector logic capable of cancelling crosstalk induced by an active transceiver that is a member of the vectoring group. Further, the line cards are coupled to one another via a ring connection across which vectoring information is passed from one line card to the next. In the event of a failure of one of the line cards, the failed card is bypassed by the vectoring stream so that the operational line cards can continue crosstalk vectoring operations despite such failure.

Abstract: A controller at a distribution point (DP) of a communication system is coupled to a plurality of customer premises (CP) transceivers via drop connections in a point-to-multipoint architecture. Each drop connection is coupled to at least one switch that operates under the control of the controller for selectively isolating the drop connection from the controller, as well as the CP transceivers of other drop connections. In this regard, by controlling the states of the switches, the DP controller can control to which of the CP transceivers it is communicatively connected, and during operation the DP controller controls the switches such that it is communicatively connected only to the CP transceivers for which communication is desired or needed during a particular time interval.

Abstract: A discrete multi-tone (DMT) transceiver communicates tones across a subscriber line. Vectoring is employed in an effort to reduce the effects of crosstalk. However, for some tones, such as tones significantly affected by radio frequency interference (RFI) or other forms of alien noise, vectoring may actually introduce distortions such that the vectoring degrades rather than improves overall signal quality. Control logic of the DMT transceiver is configured to sense when tones are affected by significant levels of alien noise and to exclude such tones from vectoring, thereby improving signal quality for such tones. The control logic also may lower the constellation densities of such tones in order to accommodate the vectoring exclusions applied to such tones.

Abstract: A communication system comprises a plurality of line cards having transceivers coupled to a plurality of subscriber lines. Each line card has at least one active transceiver within the same vectoring group, and each line card also has vector logic capable of cancelling crosstalk induced by an active transceiver that is a member of the vectoring group. In the event of a vectoring fault that prevents a line card from receiving vectoring information from at least on other line card, the vector logic is configured to disable vectoring for the interferers affected by the error in order to prevent vectoring operations based on obsolete vectoring coefficients from adversely affecting the quality of the communicated signals. The transceivers communicating signals affected by the suspended vectoring operations are also configured to adjust their constellation density profiles, thereby reducing their data rates, to accommodate the increased noise level resulting from the loss of vectoring.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: The present disclosure generally pertains to systems and methods for diagnosing loop anomalies for bonded-loop communication media. In one exemplary embodiment of the present disclosure, a communication medium comprises a plurality of bonded loops that couple network communication equipment (e.g., communication equipment at a central office) to customer premises (CP) communication equipment residing at a customer premises. If communication occurring over one of the loops becomes significantly degraded (e.g., if the SNR of the loop falls below a predefined threshold or id communication across the loop is interrupted), then loop diagnostic logic at the customer premises performs a diagnostic test on the loop. Information indicative of the diagnostic test is then communicated to the network equipment via one of the other bonded loops. Thus, the network service provider is able to receive information indicative of the diagnostic test without having to send a technician to the customer premises.

Abstract: A system for detecting non-linear distortion comprises an error detector and logic. The error detector is configured to estimate signal errors associated with signals communicated across a telecommunication line. The logic is configured to track the signal errors and to detect whether the signals are subject to non-linear distortion based on a history of the signal errors.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: A system for adaptively updating precoder taps comprises a first signal path, a second signal path, a delay mechanism, and logic. The first signal path is configured to receive encoded signals. The first signal path has a decoder that is configured to decode the encoded signals thereby recovering data originally transmitted from a remote transmitter. The delay mechanism is configured to receive and delay the encoded signals. The second signal path is connected in parallel with the first signal path and is configured to receive the encoded signals delayed by the delay mechanism. The second signal path has an adaptive filter configured to filter the encoded signals received by the second signal path based on a set of coefficients of the adaptive filter. The adaptive filter is configured to adaptively update the coefficients based on the data recovered by the first signal path.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: A system for detecting non-linear distortion comprises an error detector and logic. The error detector is configured to estimate signal errors associated with signals communicated across a telecommunication line. The logic is configured to track the signal errors and to detect whether the signals are subject to non-linear distortion based on a history of the signal errors.

Abstract: An apparatus, method and system are provided for correlated noise reduction, in a trellis decoding environment, such as second generation HDSL, in which crosstalk impairments may be significant. The preferred embodiments provide equalization and correlated noise reduction, utilizing a training period to generate corresponding coefficients, and utilizing two different training error signals. In addition, the apparatus method and system also provide continued and adaptive correlated noise reduction during data transmission, utilizing two additional error signals, a trellis error signal and a tentative error signal. The trellis error signal is a decision error of a selected previous state of a selected trellis path, in which the selected trellis path has a smallest cumulative error of a plurality of trellis paths, and the selected previous state is preferably the immediately previous state.

Abstract: An anomaly detection system comprises an echo canceler and anomaly detection logic. The echo canceler has a plurality of taps respectively associated with a plurality of tap coefficients. The anomaly detection logic is configured to determine a difference between a new tap coefficient associated with one of the taps and a previous tap coefficient associated with the one tap. The anomaly detection logic is configured to perform a comparison between the difference and a threshold and to detect an anomaly along a telecommunication line based on the comparison.

Abstract: A non-linear echo cancellation scheme for a digital transceiver coupled to a wireline medium effectively mitigates against non-linear line perturbations that may cause disruption of digital communication services. A first embodiment employs a fast, linear echo canceler, and a truncated non-linear Volterra canceler coupled to an error cancellation location in the data signal flow path downstream of the data pump's linear equalizer. A second embodiment employs only a nonlinear Volterra echo canceler, the output of which is coupled to an error cancellation location in the data signal flow path upstream of the data pump's linear equalizer. A third embodiment employs a linear echo canceler with high gain setting on selected taps, and a truncated non-linear Volterra canceler coupled to an error cancellation location in the data signal flow path downstream of the data pump's linear equalizer.

Abstract: A fiber quadrupler device and method multiplexes the four optical fibers in a synchronous optical network (SONET) ring into a single linking fiber for full duplex optical transmission. The fiber quadrupler device optically couples two of the SONET fibers to a transmit converter for communications of downstream data from the SONET ring to a network element linked to the quadrupler by a single linking fiber. Two other SONET ring fibers are optically coupled to a receive converter for communications of upstream data from the network element over the single linking fiber to the SONET. An optical transceiver processes and directs the downstream and upstream signals to the receive and transmit converters. Either subcarrier modulation (SCM) or wavelength division multiplexing (WDM) is used in the receive and transmit converters.

Abstract: An apparatus, method and system are provided for correlated noise reduction, in a trellis decoding environment, such as second generation HDSL, in which crosstalk impairments may be significant. The preferred embodiments provide equalization and correlated noise reduction, utilizing a training period to generate corresponding coefficients, and utilizing two different training error signals. In addition, the apparatus method and system also provide continued and adaptive correlated noise reduction during data transmission, utilizing two additional error signals, a trellis error signal and a tentative error signal. The trellis error signal is a decision error of a selected previous state of a selected trellis path, in which the selected trellis path has a smallest cumulative error of a plurality of trellis paths, and the selected previous state is preferably the immediately previous state.