This read-only integer reports the lowest receive signal level, in dBm, recorded during a specific historical 15-minute interval indexed by wvLinkIntervalNumber. An engineer checks this to find exactly how deep a fade dipped during a particular past quarter-hour, which is essential evidence when investigating a reported service blip. For example, finding a sharply low wvlinkIntervalMinimumRSL in one specific interval, but not in the ones before or after, would pinpoint a brief, isolated fade event rather than an ongoing problem.