This reports the normalized total received optical power at the OTS level for this line, expressed as a plain Integer32 relative value rather than an absolute dBm reading. Because this reading sits in the rolling window of completed 15-minute history bins for this wavelength/line, the normalization lets this line's aggregate power be compared against its own expected power budget regardless of how many wavelengths are currently provisioned on it. For example, a value near 0 means the whole fiber's combined power sits at its expected budget; a large negative reading here despite normal individual OCh values suggests a channel-count mismatch or a tap/splitter loss on this line, within that completed 15-minute window.