100
SCAN-LAN VI
Calculated Power Sum NEXT compared to pair-to-pair NEXT for a typical
link is shown in Figure 8-14. Power Sum NEXT can be nearly 5 dB worse
than the pair-to-pair NEXT. Consequently, the Power Sum NEXT test holds
the cable up to a higher standard, providing additional assurance that the
link will support future high-speed networks.
Figure 8-14. Power Sum NEXT Measurement.
The characteristics of Power Sum NEXT are very similar to those of NEXT.
They both vary with frequency, are measured in decibels (a larger value is
better), and are highly dependent on maintaining the wire twist up to the
connector when terminating the cable.
To minimize Power Sum NEXT, you must minimize the NEXT of all pairs.
Refer to the NEXT table in this chapter for some common causes of
excessive NEXT and their solutions.
Summary of Contents for SCAN-LAN VI
Page 2: ......
