How coverage is mapped

The figures on this site are only as good as a reader's grasp of what a carrier filing is. These three pages cover it.

• How the FCC's coverage maps are made

  What a carrier files twice a year, the speed tiers, the modelling assumptions, and how a map becomes 0.1 km² hexagons.

• Outdoors, in a vehicle, and the signal strength figure

  What the two environment flags mean, why there is no indoor figure, and how to read a predicted signal in dBm.

• Checking and challenging coverage

  What FCC drive tests found, how to test a filing with the FCC's own app, and what happens to a challenge.