Coverage Hole

A coverage hole is a spot where the signal simply isn't strong enough to hold service — RSRP drops below the usable threshold and calls fail to set up or drop outright. Causes are mundane and physical: terrain shadowing behind a hill, a new building blocking what used to be a clean path, dense foliage in summer, deep indoor or basement locations, or just the awkward dead zone where three sectors' edges meet and none reaches.

It's worth separating a coverage hole (a strength problem — not enough signal) from pilot pollution or interference (a quality problem — plenty of signal, too messy to use), because the fixes are opposite. A genuine hole needs more coverage into that spot: tuning a nearby site's tilt or power to reach further, adding a small cell or repeater, or a new site if it's a persistent gap. Throwing power at an interference problem, by contrast, makes it worse. Drive and walk tests are the usual way holes get found and confirmed, and MDT increasingly flags them from real subscriber data before anyone has to go looking.