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US 9,425,858 B2Granted
UPBO for vectored DSL
AssigneeIkanos Communications, Inc.
InventorsShailendra Kumar Singh, Nicholas Philip Sands, Sigurd Schelstraete
Life of this patent
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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.
Claims15
A method for performing upstream power back-off (UPBO) in a vectored Digital Subscriber Line (DSL) system comprising a vectored group that comprises a plurality of customer premises equipment (CPE) modems and a central office (CO) equipment, wherein each CPE modem is coupled to a Digital Subscriber Line Access Multiplexer (DSLAM) via a DSL line, the method comprising:
- selecting a performance metric associated with a plurality of DSL lines in the vectored DSL system;
- determining an attenuation model based at least in part on a first target value of the performance metric and a target transmit power spectral density (PSD) for one or more frequencies used for upstream DSL transmissions in the vectored group;
- calculating, by either the CO equipment or one or more of the plurality of the CPE modems, a reference length based at least in part on the attenuation model;
- calculating a reference attenuation based at least in part on the calculated reference length;
- calculating an electrical loop length for a selected upstream frequency band based at least in part on the reference attenuation;
- determining one or more UPBO parameters based at least in part on the electrical loop length for the selected upstream frequency band;
- calculating, based at least in part on the determined one or more UPBO parameters, residual far-end crosstalk (FEXT) associated with a subset of DSL lines of the plurality of DSL lines in the vectored DSL system;
- determining a UPBO performance metric based at least in part on the calculated residual FEXT;
- recalculating the one or more UPBO parameters based at least in part on using a second target value of the performance metric to determine the attenuation model;
- and
- operating the vectored group using the recalculated one or more UPBO parameters based at least in part on an improvement in the UPBO performance metric.
8 more elements
A communications device, comprising:
- a processor and memory communicatively coupled to the processor, the memory comprising computer-readable code that, when executed by the processor, causes the communications device to:
- select a performance metric associated with a plurality of Digital Subscriber Line (DSL) lines of a vectored DSL system;
- determine an attenuation model based at least in part on a first target value of the performance metric and a target transmit power spectral density (PSD) for one or more frequencies used for upstream DSL transmissions in the vectored group;
- calculate a reference length based at least in part on the attenuation model;
- calculate a reference attenuation based at least in part on the calculated reference length;
- calculate an electrical loop length for a selected upstream frequency band based at least in part on the reference attenuation;
- determine one or more upstream power back-off (UPBO) parameters based at least in part on the electrical loop length for the selected upstream frequency band;
- calculate, based at least in part on the determined one or more UPBO parameters, residual far-end crosstalk (FEXT) associated with a subset of DSL lines of the plurality of DSL lines in the vectored DSL system;
- determine a UPBO performance metric based at least in part on the calculated residual FEXT;
- recalculate the one or more UPBO parameters based at least in part on using a second target value of the performance metric to determine the attenuation model;
- and
- operate the vectored group using the recalculated one or more UPBO parameters based at least in part on an improvement in the UPBO performance metric.
9 more elements
A non-transitory computer-readable medium comprising computer-readable code that, when executed, causes a device to:
- select a performance metric associated with a plurality of Digital Subscriber Line (DSL) lines of a vectored DSL system;
- determine an attenuation model based at least in part on a first target value of the performance metric and a target transmit power spectral density (PSD) for one or more frequencies used for upstream DSL transmissions in the vectored group;
- calculate a reference length based at least in part on the attenuation model;
- calculate a reference attenuation based at least in part on the calculated reference length;
- calculate an electrical loop length for a selected upstream frequency band based at least in part on the reference attenuation;
- determine one or more upstream power back-off (UPBO) parameters based at least in part on the electrical loop length for the selected upstream frequency band;
- calculate, based at least in part on the determined one or more UPBO parameters, residual far-end crosstalk (FEXT) associated with a subset of DSL lines of the plurality of DSL lines in the vectored DSL system;
- determine a UPBO performance metric based at least in part on the calculated residual FEXT;
- recalculate the one or more UPBO parameters based at least in part on using a second target value of the performance metric to determine the attenuation model;
- and
- operate the vectored group using the recalculated one or more UPBO parameters based at least in part on an improvement in the UPBO performance metric.
8 more elements
Dependencies are inferred from the claim text.