Not that it said anything in the movie, but I propose communication via quantum entanglement. It'd explain why the link worked when the radios didn't, there's n

Not that it said anything in the movie, but I propose communication via quantum entanglement. It'd explain why the link worked when the radios didn't, there's no real signal to block, and it just sounds fucking cool. Spooky action at a distance is a great plot device for any sci-fi movie and at least partially based on real science.