Summary

Recommendation ITU-T G.9701 specifies a gigabit broadband access technology that exploits the existing infrastructure of wire-pairs that were originally deployed for plain old telephone service (POTS) services. Equipment implementing this Recommendation can be deployed from fibre-fed distribution points (fibre to the distribution point, FTTdp) located very near the customer premises, or within buildings (fibre to the building, FTTB). This Recommendation supports asymmetric and symmetric transmission at an aggregate net data rate up to 1 Gbit/s on twisted wire-pairs using spectrum up to 106 MHz and specifies all necessary functionality to support far-end crosstalk (FEXT) cancellation between multiple wire-pairs, and facilitates low power operation.

Corrigendum 1 (2015) provides clarifications and corrects various errors in the Recommendation, and in particular includes a change to the definition of DFT output samples.

Corrigendum 2 (2016) increases the number of RFI bands from 16 to 32, and provides clarifying text on alignment between TIGA and SRA/FRA procedures, tone repetition, unavailable seconds, and byte order in SOC and eoc messages.

Amendment 1 (2016) specifies test parameters, some of which had previously been left for further study, and specifies support for low power operation.

Amendment 2 (2016) includes a new annex on cross-layer traffic monitoring functions and link state control to support low power operation. It also includes a new 106 MHz profile with increased maximum transmit power, support for increased bit loading, Hlog reporting in both directions, and Xlog reporting.

Corrigendum 3 (2017) adds several clarifications, and fixes various errors and inconsistencies.

Amendment 3 adds support for new functionality: full specification of the 212 MHz profile, Annex X – Operation without multi-line coordination intended for a crosstalk free environment (e.g., coaxial cable medium) including independent dynamic time assignment (iDTA), Annex T – higher layer control aspects of DTA, and Annex S – software download to NTs.

Amendment 4 supports new functionality for impulse noise monitoring (INM), robust management channel recovery (RMCR), and performance monitoring parameter ANDEFTR.

Corrigendum 5 adds several clarifications, and fixes various errors and inconsistencies.

Amendment 5 adds support for coordinated dynamic time assignment (cDTA).

Recommendation ITU-T G.9701 (2019) integrates ITU-T G.9701 (2014) and all of its corrigenda and amendments, and adds support for the following new functionality: LPM classes, optional extension of probe sequence length, short CLR/CL messages, Annex R – Showtime reconfiguration, and Appendix IV – Targeted generalized vectoring with active ITU_T G.9701 supporting lines (TGVA). It also adds several clarifications, and fixes various errors and inconsistencies including ANDEFTR support, SRA triggering and PMS-TC parameter requirements, and conditions for an rtx-uc anomaly.