Near-End Crosstalk (NEXT)
One of the most important cable measurements is Near-End Crosstalk (NEXT). It’s signal interference from one pair that adversely affects another pair on the same end. Crosstalk occurs between adjacent wire pairs (“pair-to-pair NEXT”). In addition, all other pairs in a UTP cable can also contribute their own levels of both NEXT and Far-End Crosstalk (FEXT), multiplying the adverse effects of interference onto a transmitting or receiving wire pair. These compounded levels of interference can prove crippling. So check your NEXT ratings on any CAT5e and CAT6 cable you purchase.
Near-End Crosstalk (NEXT) NEXT measures an unwanted signal transmitted from one pair to another on the near end.
Power Sum Near-End Crosstalk (PS-NEXT)
PS-NEXT measures the unwanted signals from multiple pairs at the near end onto another pair at the near end.
Far-End Crosstalk (FEXT)
FEXT measures an unwanted signal from a pair transmitting on the near end onto a pair at the far end. Full-duplex operation is taken into account where signals are generated simultaneously on both ends.
Power Sum Equal-Level Far-End Crosstalk (PS-ELFEXT)
PS-ELFEXT measures the total sum of all interference from pairs on the far end onto a pair on the near end without the effects of attenuation.
More about PS-NEXT