
failure probability is kept within the design limits. It can be shown that the
outage probability of 10
6
(or 30 seconds per year) requires a PMD value that is
less than one-third of DGD
max
. Some examples of PMD fiber requirements
based on this analysis are shown in Table 5.1 [36].
5.5.8 Summary of Design Principles
Based on the previous discussion, a Tx fiber with reduced dispersion (relative
to G.652 fiber) and low RDS offers system advantages in wideband dispersion
compensation, reduced attenuation, PMD, and nonlinear penalties for the DCM
module, avoidance of nonlinear impairments in distributed Raman amplifica-
tion, as well as high efficiency