Complex sentence: A dirtbox (or DRT box) is a cell site simulator, that is, a phone device mimicking a cell phone tower, designed to create a signal strong enough within a short range so as to force dormant mobile phones to automatically switch over to it.
Split into simpler sentences: A dirtbox (or DRT box) is a cell site simulator, a phone device mimicking a cell phone tower. It was designed to create a signal strong enough within a short range so as to force dormant mobile phones to automatically switch over to it.