Summary

Vectoring is a transmission method that employs the coordination of line signals for reduction of crosstalk levels and improvement of performance. The degree of improvement depends on the channel characteristics. Vectoring may be for a single user or for multiple users' benefit.

Recommendation ITU-T G.993.5 is specifically limited to the self-far-end crosstalk (self-FEXT) cancellation in the downstream and upstream directions. It defines a single method of self-FEXT cancellation, in which FEXT generated by a group of near-end transceivers and interfering with the far-end transceivers of that same group is cancelled. This cancellation takes place between very high-bit-rate digital subscriber line 2 (VDSL2) transceivers, not necessarily of the same profile. This Recommendation is intended to be implemented in conjunction with Recommendation ITU‑T G.993.2.

ITU-T G.993.5 (2015) consolidates ITU-T G.993.5 (2010) with all its amendments and corrigenda.

Amendment 1 defines the following new functionality: Transceiver O-DEACTIVATING state.

Amendment 2 adds Annex A: Mitigating strong FEXT; and Annex B: Vectored Long Reach VDSL2.