The President and his staff have to be kept well informed of everything that's going on all day, every day. They don't want to be caught by surprise by landing and finding out something has happened while they were in the air.
To avert that risk, Air Force One is kitted out with eight-five phones, one of which the ultra-secure Airborne Security Phone. There are also 20 full-sized TVs. We wonder which channels it receives? Does it depend on which country you're flying over?