US 7991122

Patent Overview — US 7,991,122 B2

Title: DSL system training
Patent number: US7991122B2 (application US11/345,215)
Assignee (current, as listed): Adaptive Spectrum and Signal Alignment Inc.
Inventors: John M. Cioffi, Wonjong Rhee, Bin Lee, Georgios Ginis
Priority date: 2005-06-02 | Filed: 2006-02-01 | Granted/Published: 2011-08-02
Status listed: Active, adjusted expiration 2030-06-04

Purpose. The patent concerns managing digital subscriber line (DSL) systems, specifically "training DSL systems when adding new lines." It addresses the problem that activating a previously unused twisted pair (or upgrading service) can disrupt already-operating DSL lines through crosstalk, and that in a vectored system, activating a new line may require reconfiguration to avoid disrupting strong crosstalk.

Plain-language scope. Rather than requiring a new line to be "polite" voluntarily, the invention compels politeness by imposing existing transmit-power, CARMASK, and/or PSDMASK capabilities (e.g., as used in VDSL2 / G.997.1 as modified for VDSL2) before the new line trains. PSDMASK levels across all or part of the training band are set low on initial training; already-operating lines (likely, but not necessarily, in the same binder) are then scanned for a faint, non-disruptive crosstalker—the new line. A controller (for example, a DSL Optimizer) assesses the crosstalker, updates vectored and/or non-vectored devices, and only then allows the new line to train at higher signal levels, e.g., to reach a desired data rate. The approach extends to non-vectored DSLs in a binder, and to a new RT line whose low-power training lets its effect on existing CO lines be observed before its PSDMASK or data rate is properly defined to limit disturbance while guaranteeing the new line a proper rate.

Source: https://patents.google.com/patent/US7991122/en

What the excerpt does not establish: It does not provide the full claims, complete description, drawings (FIG. 1 is truncated), or the exact PSDMASK/CARMASK values and algorithms used. It also does not establish the current legal owner, validity, or the full litigation/PTAB history.