多项选择题
A. offset the OADM loss at site B
B. overcome the high multiplexer loss at site A
C. amplify signal levels after the high loss through Fiber Span 1
D. adjust add channels at site B to be at the same level as the passthrough channels
E. ensure that the per channel power is higher than the minimum needed for the post-amp at Site B
单项选择题 In the OSNR model for EDFA amplifiers， SNR OUT = 1/（1/SNR IN + FhvB/P IN ）， what does SNR IN represent？（）
单项选择题 The dispersion of a non-zero dispersion shifted fiber is 6 ps/nm*km at 1550 nm and 10 ps/nm*km at 1610 nm. What is the minimum dispersion compensation required if an L-Band DWDM signal travels through 200 km of fiber and has a dispersion tolerance of 1800 ps/nm？（）
单项选择题 Forlaserswithtightlycontrolledwavelengths，approximatelyhowfarapartarethecentersofadjacentwavelengthswhen100GHzspacingisusedinaDWDMsystem？（）
