Vectored VDSL2: Theoretical possibilities on quad cables

Mitigating unwanted effects of crosstalk in highspeed communications over copper-based digital subscriber lines (DSL) is well researched area. On the other hand effects of vectored transmission in access network based on quad cables instead of twisted pair cables is poorly covered. In such an environment, crosstalk models often do not behave intuitively and the results obtained using the standard crosstalk models can give surprising results. In this paper we calculate potentially achievable data rates, in downstream direction for VDSL2 (Very-high-bit-rate DSL 2) systems, with respect to loop length and cable filling percentage, taking into account vectoring applied on quad cables. Presented results are supported by laboratory measurements of attenuation and far-end crosstalk (FEXT). Finally, results provide useful bounds for developers, xDSL providers, and relevant regulatory agencies.