
from the pdf’s truncation at a finite : the PMD vector cannot be longer than the
sum of the (relatively fixed) buried section PMDs. Unfortunately, in a system with
hinges, a small fraction of channels have a higher than specified outage prob-
ability. To account for this, the second measure (NCR) was introduced [50], which
used the outage map approach rather than simply evaluating the probability for an
instantaneous DGD to exceed a threshold [21]. Interestingly, the more rigorous
analysis [50] exhibits similar qualitative behavior.
This new way of looking at outages highlights the utmost importance of in-
service PMD monitoring techniques [37, 46, ...