US -> GSM/ Iden Range?

[Lord of nothing]

Hi
What was the Coverage in ~2000 with an GSM/ Iden Phone?
Here an Youtube Channel about the 11.9 have an theory that Cellphones dont work onboard an Aircraft.
I know as an CB/ PMR446 user that the Radio Waves can travel with an very low output power very far.

Another question is are Window in the Aircraft big enough to lett the Waves truth the Window?