BS EN 61280-4-2. Fibre-optic communication subsystem test procedures. Part 4-2. Installed cable plant. Singlemode attenuation & optical return loss measurement Fibre optics, Optical communication systems, Optical fibres, Fibre optic connectors, Fibre optic cables, Optoelectronic devices, Performance testing, Attenuation, Performance, Test equipment, Power measurement