Chapter 3: Certify Twisted Pair Cabling
Frequency-Domain Results
81
PS NEXT (Power Sum Near End Crosstalk)
PS NEXT results show how much each wire pair is affected by the
combined crosstalk from the other pairs. PS NEXT is the difference
(in dB) between the test signal and the crosstalk from the other
pairs received at the same end of the cabling. The tester uses the
NEXT values to calculate PS NEXT. Higher PS NEXT values
correspond to better cabling performance.
PS NEXT results are typically a few dB lower (worse) than worst-
case NEXT results. Figure 37 shows the PS NEXT plot. The tester
puts the cursor at the worst margin.
Note
If the PS NEXT result is an an , the 4 dB rule
applies. See “About dB Rules” on page 90.
BA105.PNG
Figure 37. PS NEXT Plot
To Next Page
Loading...
