Customer has 10G DWDM system and want to upgrade to 40G system. the PMD requirements for 40G is different from 10G system. PMD value for the optical fiber link should be tested before system being upgraded to 40G system
and compared to the stanard PMD delay limit.
PMD requirements for 10G system as below:
PMD delay limit = 10 PS
PMD Coefficient for 400 Km <0.5
PMD requirements for 40G system as below:
PMD delay limit = 2.5 PS
PMD Coefficient for 400 Km <0.125