The Unger Model is an empirical standard model for

near-end crosstalk In electronics, crosstalk is any phenomenon by which a signal transmitted on one Electronic circuit, circuit or Communication channel, channel of a transmission system creates an undesired effect in another circuit or channel. Crosstalk is usua ...

(NEXT)

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

spectra as experienced by

communication Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquir ...

systems over

unshielded twisted pair Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted bal ...

(UTP). Twisted pair cables are usually grouped together in a binder where they experience

crosstalk In electronics, crosstalk is any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel. Crosstalk is usually caused by undesired capacitive, induc ...

. Based on empirical observations, Unger J. H. Unger, "Near-End Crosstalk Model for Line Code Studies", ''ECSA Contribution'', T1D1.3/85-244, November 12, 1985. proposed that, at the 1% worst case, the NEXT power spectra

, H_(f), ^2

, due to a single disturber, can be bounded by
:

10\log(, H_(f), ^2)=\begin -66 + 6\log(f) dB & f < 20 KHz \\ -50.5 + 15\log(f) dB & f >= 20 KHz \end

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

10\log(, H_(f), ^2)=\begin -59.2 + 4\log(f) dB & f < 20 KHz \\ -42.2 + 14\log(f) dB & f >= 20 KHz \end

References

See also