What Causes A Dead Zone
What causes my mobile not to work in certain areas?
Simple math causes dead zones. If you are not close enough to a cell phone tower you will find a dead zone. Most cell phone towers rely on line of sight. IF you can see one of your towers then you should have service. The hard places to have service is in a mountain region.
While traveling there are certain parts of the trip that I know are going to cut my access to the internet even though there is nothing really blocking. Sometimes I think that maybe somebody has some kind of jammer device nearby even if unintentional it causes the disruption.