This part of IEC 61753 contains the minimum initial performance@ test and measurement requirements and severities which a fibre optic pigtailed 1 490 / 1 550 nm downstream and 1 310 nm upstream wide wavelength division multiplexing (WWDM) passive optical network (PON) device must satisfy in order to be categorized as meeting the requirements of category C (controlled environments)@ as defined in Annex A of IEC 61753-1. Annex B of this standard provides information concerning the function of the 1 490 / 1 550 nm downstream and 1 310 nm upstream WWDM.