This application provides an optical
signal-to-
noise ratio (OSNR) monitoring method,
system, and storage medium, relating to, but not limited to, the field of communication technology. The OSNR
monitoring system includes a
control unit and multiple OSNR monitoring units distributed throughout an
optical transport network (OTN). Each OSNR monitoring unit is correspondingly located at the output end of an optical amplification unit within the OTN. Each OSNR monitoring unit determines the output channel
optical power of its corresponding optical amplification unit; each OSNR monitoring unit determines the corresponding channel OSNR based on the output channel
optical power; the
control unit monitors the OSNR of the OTN based on the channel OSNR of each OSNR monitoring unit. By corresponding the OSNR monitoring units with optical amplification units, each OSNR monitoring unit can calculate independently, and the
control unit enables monitoring at any location, thereby improving the reliability, hardware integration, monitoring range, monitoring efficiency, and
maintainability of OSNR monitoring.