Abstract: Techniques are described for reducing shared cache memory requests in a multi-threaded microprocessor-based system. One method includes receiving a request for data from a thread, identifying that the request correlates with a pending request associated with a different thread, combining the request with the pending request based on the identifying, and receiving the data after the combining, the receiving being based on the pending request. In some examples, the request may be associated with an address of a cache line in a cache memory.

Abstract: This disclosure provides systems, methods, and apparatus for wireline communication. A digital subscriber line (DSL) receiver may detect one or more power line communication (PLC) sound packets and measure PLC signal leakage on a set of DSL lines based on the detected sound packets. For example, PLC sound packets may be transmitted by PLC devices within a PLC network, and impulse noise received on the set of DSL lines corresponding to the transmitted PLC sound packet may be detected by a DSL receiver (such as a consumer premises equipment (CPE)). The DSL receiver may measure PLC signal leakage on the set of DSL lines based on the detected PLC sound packets. In some cases, the PLC sound packets may be detected based on a duration, a position, or an arrival time of a PLC sound packet.

Abstract: In some aspects, a calibration method includes performing a write/read test for each one of multiple combinations of write/read delay settings, wherein each one of the multiple combinations of write/read delay settings includes one of a plurality of write delay settings of a first delay device and one of a plurality of read delay settings of a second delay device. The method also includes obtaining test results for the write/read tests, determining a pass region based on the test results, determining a center of the pass region, and selecting one of the multiple combinations of write/read settings based on the center of the pass region.

Abstract: The present invention relates to methods and apparatuses for managing the time slots in time division duplex (TDD) frames in an xDSL system. According to certain aspects, power savings in a TDD system operating with vectoring may be achieved with sending of quiet symbols in time slots that do not have data and through the efficient configuration of time slots with data and/or idle symbols so as to limit the amount of processing by the vectoring engine within the DO portion of each TDD frame. In embodiments, a central controller in a DPU monitors the data buffers at the transmitter input on each line and computes an optimal configuration of the time slots in the DO portion of the TDD frame to achieve an optimal balance between performance and power dissipation.

Abstract: The present invention relates to methods and apparatuses for sensing noise sources in a wireline communications environment such as a customer premises environment in a DSL system. In embodiments, the invention includes an additional sensor that is connected to power mains in a DSL customer premises environment either to characterize, at their source, noises coupling into the DSL lines, and/or to mitigate their impact into the DSL lines. One objective is associated with diagnostics that help to better characterize the noise signals themselves and derive correlation of signals sensed from the power mains and their possible projection onto the DSL line. Another objective makes use of these power line sensor signals to mitigate or to eliminate power line noises that make their way onto the DSL line. Example embodiments further include and exploit signals from additional secondary sensors such as secondary common mode, differential mode and phantom mode sensors.

Abstract: A vector DSL system includes a plurality of modems, which may be multi-port devices. Unprocessed user data is extracted from the modems and passed through a private vectoring data routing apparatus to one or more vectoring modules, such as vectoring cards. Each vectoring module includes one or more vector processors that include processing units configured to process the unprocessed user data on the basis of all modems' data for a given DSL tone grouping. Processing of the unprocessed user data removes the effects of FEXT from upstream and downstream user data and returns the processed user data to the modems using the vectoring data routing apparatus, which can be a specialized data transmission network utilizing one or more vector routers.

Abstract: Methods, systems, and devices are described for wired communication. In one aspect, a method includes selecting a gain scalar based at least in part on a constellation point distance associated with a constellation mapper for a line and a tone. The method also includes applying the gain scalar to a tone data output signal of a vector processor.

Abstract: The present invention relates generally to addressing performance issues in xDSL communication systems, and more particularly to methods and apparatuses to measure and characterize CM noise impacting a DSL line in a customer premises, measurements and characterization of the projection of these CM signals in Differential Mode (DM), and finally a derivation of an estimate of the loop balance.

Abstract: In general, the present invention provides an efficient usage of Far End Crosstalk (FEXT) coefficient memory in a G.fast vectoring system. According to certain aspects, embodiments of the invention provide a simple scheme for efficient management of the Discontinuous (DO) and Regular Operation (RO) FEXT coefficient memories to handle the complexity of lines joining/leaving the system in both regular and DO groups. In embodiments, by disabling the power-efficient, Discontinuous Operation, a G.fast system according to the invention first frees up the DO coefficient memory. Next, the system uses this memory as the staging area to manage joining/leaving events. Finally the system re-enables to the power-efficient Discontinuous Operation and re-populates the DO coefficient memory.

Abstract: A reduced-memory vectored DSL system reduces the bandwidth and memory storage demands on a vectored DSL system in which FEXT data is transmitted and stored. When test signal data, such as training and/or tracking data, is sent to determine FEXT characteristics of the DSL system, error signals are available for all or substantially all of the upstream and/or downstream frequency band DSL tones used in the system. Dividing a frequency band into sub-bands, only a subset of tones in each sub-band is used for deriving FEXT data. For tones in the sub-band subsets, full-precision FEXT data values can be derived. For other tones, approximations of the FEXT data can be derived. Memory is reduced in both the transmission of such FEXT data (between upstream and downstream ends) and within an upstream-end device such as a DSLAM that performs vectoring using a separate or internal vectoring processing apparatus.

Abstract: According to certain aspects, embodiments of the invention relate to methods and apparatuses for performing diagnostics on a loop in a communications system. According to certain aspects, embodiments of the invention include performing SELT from a customer premises side of the loop. According to certain other aspects, embodiments of the invention address the issue of initiating a CPE side SELT procedure and also collecting the diagnostics data while a CPE is offline.

Abstract: The present invention provides a method and apparatus to detect a missing micro-filter. In embodiments, the detection is performed by measuring the distortion caused by an unfiltered telephone device using a SELT (Single Ended Line Test) technique. According to certain aspects, the signal used to perform the distortion measurement is designed such that it causes minimal impact on vectored lines within the same cable. Embodiments of the invention first determines the estimated loop length, then uses the loop length to select a set of signal parameters that will be used to perform the distortion measurement. The parameters to be selected include transmit frequency band and PSD level. According to further aspects, embodiments of the invention include automatically running a missing filter test immediately following a line drop to determine if the line drop was caused by a missing micro-filter.

Abstract: The present invention relates generally to characterizing loops in a communication system, and more particularly to methods and apparatuses for loop gauge identification. In accordance with certain aspects, embodiments of the invention extract some information from the SELT signal. From SELT, the loop impedance, or equivalently input impedance, is determined. This information is then used for gauge identification.

Abstract: Residual FEXT resulting from intended and/or inherent partial cancellation of crosstalk in vectored DSL systems impairs upstream power back-off (UPBO) as traditionally implemented. By considering and taking into account the effects of residual crosstalk on vectored DSL system performance and operation, improved data rates and/or other vectored DSL system performance are realized through the use of UPBO parameters generated for a given residual FEXT environment.

Abstract: The present invention relates to a method by which an xDSL modem can be properly connected and/or optimally tuned to achieve a desired performance goal based on knowledge obtained by first performing a SELT test and then post-processing the results of that test. In embodiments, the processed SELT results are used to detect bad connections or other anomalies such as split pairs. In embodiments, the processed SELT results are used to configure programmable components and filters in the analog front end in a manner that achieves the performance goal. In these and other embodiments, the performance goal is to maximize the attainable data rate. As such, through various hardware design options and configurations according to the invention, the performance of the modem can be tuned such that even in the presence of undesirable loop characteristics, adequate, or even good performance, can be achieved.

Abstract: The present invention relates to methods and apparatuses for sensing noise sources in a wireline communications environment such as a customer premises environment in a DSL system. In embodiments, the invention includes an additional sensor that is connected to power mains in a DSL customer premises environment either to characterize, at their source, noises coupling into the DSL lines, and/or to mitigate their impact into the DSL lines. One objective is associated with diagnostics that help to better characterize the noise signals themselves and derive correlation of signals sensed from the power mains and their possible projection onto the DSL line. Another objective makes use of these power line sensor signals to mitigate or to eliminate power line noises that make their way onto the DSL line. Example embodiments further include and exploit signals from additional secondary sensors such as secondary common mode, differential mode and phantom mode sensors.

Abstract: According to certain aspects, the present invention improves upon the conventional TCAM scheme by allowing a traditional TCM scheme to be used while in RCM mode. In a RCM mode according to embodiments of the invention, the system uses traditional TCM+SNR margin (i.e. SNRM) with a receiver controlled bit allocation table (BAT) and tone ordering table (TOT). In a TCAM mode according to embodiments of the invention, the system uses uncoded hierarchical modulation similar to the modulation originally proposed for TCAM. According to certain aspects, the transmitter in RCM mode in embodiments of the invention can determine when line conditions require a switch to TCAM mode, and signal the transition to the receiver. Likewise, when in a TCAM mode according to embodiments of the invention, the receiver can request to switch back to RCM via a SRA mechanism, for example.

Abstract: The present invention generally relates to a method and apparatus for effectively detecting and characterizing noise and other events affecting a communications system such as digital subscriber lines (DSL). According to certain aspects, the invention includes a noise analysis engine that is embedded in customer premises equipment that classifies noise sources according to their specific characteristics and tracks each noise source in a dynamic manner, in such a way as to provide visibility to the changing noise environment within the customer premises and/or report this environment to a remote entity.

Abstract: The present invention relates generally to addressing performance issues in xDSL communication systems, and more particularly to methods and apparatuses to measure and characterize CM noise impacting a DSL line in a customer premises, measurements and characterization of the projection of these CM signals in Differential Mode (DM), and finally a derivation of an estimate of the loop balance.

Abstract: The present invention is directed to methods and apparatuses for performing concurrent vectoring of systems having communications performed at different symbol rates. In embodiments, where a common binder includes different sub-groups of lines having corresponding different symbol rates, the invention includes methods and apparatuses for managing and concurrently vectoring all the lines of the different sub-groups.