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 proposed that, at the 1% worst case, the NEXT power spectra $$|H_{NEXT}(f)|^2$$, due to a single disturber, can be bounded by
 * $$10\log(|H_{NEXT}(f)|^2)=\begin{cases} -66 + 6\log(f) dB & f < 20 kHz \\ -50.5 + 15\log(f) dB & f \geq 20 kHz \end{cases}$$

while the NEXT power spectra due to 49 disturbers (full binder) can be bounded by
 * $$10\log(|H_{NEXT}(f)|^2)=\begin{cases} -59.2 + 4\log(f) dB & f < 20 kHz \\ -42.2 + 14\log(f) dB & f \geq 20 kHz \end{cases}$$