ATIS - Alliance for Telecommunications Industry Solutions
Scope
This document provides dynamic spectrum management information for the administration of services and technologies that use metallic subscriber line cables. Spectrum management is the administration of subscriber line technology in a way that provides spectral compatibility for services and technologies that use pairs in the same cable. American National Standard T1.417-2003 addresses spectrum management in a static form. Dynamic Spectrum Management (DSM) can enhance spectrummanagement value by improving reliability and increasing data rates through measurement and/or dynamic management of DSL configuration parameters. DSM incorporates parameters of the subscriber line environment and line transmission systems that are time or situation dependent@ which are not incorporated in the current issue of T1.417. A service provider's DSL systems may provide physical-layer channel and performance information to that service provider's maintenance entity according to specifications contained within this document. This information may optionally be used by the maintenance entity and its service provider to improve service provisioning@ reliability@ and/or data rates. DSM methods may enhance the performance of DSL services by enabling the adaptive or dynamic assignment of signals@ spectra@ and operations of DSL lines while remaining within the constraints of the static T1.417 specifications. DSM may also assist in the control of features (e.g. impulse noise protection) that help to improve the physical layer performance without changing the transmitted spectra. While the effectiveness is somewhat diminished@ DSM may also be applied to certain wire pairs of a cable@ even if there are some other wire pairs in that cable that are outside of the domain of the Spectrum Management Center (SMC). This document includes the following types of suggestions and information for defined DSL systems: ? Examples of use of DSM when a Spectrum Management Center (SMC) monitors and changes the DSL parameters (such as power@ margin@ etc.) without specific knowledge of other DSLs. ? Examples of algorithms for the autonomous control or coordination of DSL spectra and/or signals ? Examples of the use of DSM when DSL systems with dynamic spectra are present and of the use of DSM to allow a service provider to locate and correct their own DSL problems. ? Channel identification: line-dependent and binder-dependent characterization of signals@ crosstalk@ and other noise. This document is a Technical Report (TR) of ATIS Committee NIPP. As such it is neither an American National Standard (ANSI Standard) nor an ATIS NIPP Technical Requirement (TRQ). All text in this document is Informative. Purpose The purpose of this DSM document is to provide the industry with information that may allow substantial improvement in data rates@ reliability@ and relative symmetry of upstream and downstream data rates of DSL systems with respect to static spectrum management described in ANSI T1.417. The techniques in this report allow enhanced spectrum-management procedures and build upon the techniques that were standardized in ANSI T1.417. To this purpose@ this document defines mechanisms for characterizing and describing DSL systems that may autonomously or through coordination improve the performance of one or more DSL services within a cable without reducing the performance or disrupting the operation of DSL systems while remaining compliant with T1.417. DSL systems (that are owned@ operated and maintained by a Network Operator) may provide physical-layer channel and performance information to their own maintenance entity according to information contained within this document. Coordination or sharing of DSM related information between Network Operators (or Service Providers) whose DSL systems may share the same access cable plant is outside the scope of this Technical Report.