This was brought up in a thread today and me and a buddy had a discussion on it
Cell phones work off satelites, arnt you therefore closer to the satelite and in less frequency disturbance in the air. So is it the speed that ruins the signal? Does the airplane itself have equipement that purposely blocks signals? If the later is true if you could theoreticalLy float in the air at 20,000 feet would you get a signal?*