IEC 61753-381-6:2016 contains the minimum initial test and measurement requirements and severities which a Gaussian-passband-profile cyclic arrayed waveguide grating (AWG) for single bidirectional transmission systems satisfies in order to be categorised as meeting the requirements of IEC 61753-1 for category O (uncontrolled environment). This standard pertains to wavelength division multiplexing (WDM) network with multiple spectral-band usage. This standard covers the requirements of cyclic AWG devices with free spectral range (FSR) characteristics to ensure multiple spectral bands transmission performance. The requirement covers devices with single-mode non-connectorized pigtails and no electric circuit board. Keywords: Keywords: Gaussian-passband-profile cyclic arrayed waveguide grating (AWG), wavelength division multiplexing (WDM), category O (uncontrolled environment)