Near End Crosstalk
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Near End Crosstalk (NEXT) is an electromagnetic interference (EMI), also known as crosstalk, introduced on UTP by closeby wires, usually running in parallel with the NEXT induced wire.
"Near End" refers to the inductance of EMI in the end closer to the end being measured on the alternate wire in a pair.
In opposition to this, FEXT (Far End Cross Talk) is the detection of EMI one a wire whose inductance is at the far end from the measurement point. Obviously FEXT is weaker at the other end due to attenuation of the crosstalk signal.
Crosstalk is generally computed as the ratio in voltage between a "test signal" and the induced crosstalk signal in an alternate wire.
Professional computer network cabling must pass TIA/EIA (Telecommunications Industry Association/Electronic Industries Association) standards tests, generally TIA/EIA-568-B standard.