VDSL2 vectoring works on a single pair and is based on the concept of “noise cancellation”, much like the headphones people have started to use increasingly on Rate Reach of VDSL2 and VDSL2 Bonding planes, to reduce or cancel background/ engine noise when listening to music or watching a movie. VDSL2 vectoring calculates the interference between all pairs in a binder, based on the actual signals, and will use this information to generate a noise cancellation signal on each pair, effectively removing all crosstalk. See the figure below.
Due to the amount of calculations involved, vectoring will provide the best results in nodes with a limited number of lines (FTTN or FTTB deployments). The only requirement is that all lines are under full control of a single operator, meaning that there can be no sub-local loop unbundling (Highlander principle: “There can be only one”). Indeed, if the lines belong to multiple operators and are terminated on different nodes, then there is no way to collect all the signal and crosstalk data.