Advanced Forward Link Trilateration. AFLT is a type of device-based position location technology. Trilateration is a method for determining the intersections of three sphere surfaces given the centers and radii of the three spheres. Unlike A-GPS, AFLT does not use GPS satellites to determine location. To determine location, the cell phone takes measurements of signals from nearby cellular base stations (towers) and reports the time/distance readings back to the network, which are then used to triangulate an approximate location of the cell phone. In general, at least three surrounding base stations are required to get an optimal position fix. For successful results, AFLT requires an accurate Base Station Almanac consisting of cell sector identity information, cell sector GPS coordinates, a proper AFLT calibration, and values for uncertainties in measurements. Q: How accurate is AFLT if you are not using real satellites. A: AFLT accuracy is limited to the geometry of the Cell towers sur