NF C93-807-2-9*NF EN 61280-2-9:2009 Fibre optic communication subsystem test procedures - Part 2-9 : digital systems - Optical signal-to-noise ratio measurement for dense wavelength-division multiplexed systems.
2009NF C93-807-2-9*NF EN 61280-2-9:2009 Fibre optic communication subsystem test procedures - Part 2-9 : digital systems - Optical signal-to-noise ratio measurement for dense wavelength-division multiplexed systems.