​​What is Cell Tower Triangulation?

Cell tower triangulation is similar to GPS tracking in many ways. Multiple towers are used to track the phone’s location by measuring the time delay that a signal takes to return back to the towers from the phone. This delay is then calculated into distance and gives a fairly accurate location of the phone.  Detecting which antenna of the tower the signal bounced off of can further refine the location. This gives a more specific location when used congruently with multiple towers calculated by multiple dishes on each tower. 
The cell tower triangulation data can be used forensically in many ways to achieve many objectives, i.e. intelligence, criminal location verifications, alibi confirmation etc.