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 If the dispersion of a given fiber is 17ps/nm*km at 1550 nm and zero at 1310 nm, then what is the accumulated dispersion of an ITU wavelength after it travels 200 km?（）

多项选择题 What are three factors that limit the maximum distance of an amplified optical signal without regeneration? （）(Choose three.)