This is the lowest value recorded during the current performance-monitoring interval of the Q-factor measured on this channel during the current performance-monitoring interval, expressed in dB, a composite measure of signal quality that correlates with the expected bit error rate. The lowest Q-factor seen in the interval matters most, since it represents the point closest to the transponder's minimum acceptable signal quality before FEC can no longer guarantee error-free service. For example, if qFactorMin for a channel dips dangerously close to the FEC threshold during a specific hour each day, an admin would look for a correlated environmental or traffic-load event at that same hour.