FIELD: communication.
SUBSTANCE: invention relates to communication engineering and can be used to detect optical signal-to-noise ratio, node device and network system. Method involves: receiving detected optical signal carrying noise amplified spontaneous radiation (ASE); detection of first current variable component and first permanent current component of detected optical signal; obtaining first information modulation of detected optical signal; obtaining first information corresponding to correction of first information modulation, according to first information modulation; and determining optical signal-to-noise ratio (OSNR) of detected optical signal according to first current variable component, first constant current component and first correction information.
EFFECT: technical result consists in improvement of quality of receiving information.
17 cl, 19 dwg
