Unger model

The Unger Model is an empirical standard model for near-end crosstalk (NEXT) power spectra as experienced by communication systems over unshielded twisted pair (UTP).

Twisted pair cables are usually grouped together in a binder where they experience crosstalk. Based on empirical observations, Unger ^[1] proposed that, at the 1% worst case, the NEXT power spectra ${\displaystyle |H_{NEXT}(f)|^{2}}$, due to a single disturber, can be bounded by

${\displaystyle 10\log(|H_{NEXT}(f)|^{2})={\begin{cases}-66+6\log(f)dB&f<20kHz\\-50.5+15\log(f)dB&f\geq 20kHz\end{cases}}}$

while the NEXT power spectra due to 49 disturbers (full binder) can be bounded by

${\displaystyle 10\log(|H_{NEXT}(f)|^{2})={\begin{cases}-59.2+4\log(f)dB&f<20kHz\\-42.2+14\log(f)dB&f\geq 20kHz\end{cases}}}$

• Digital subscriber line