I beg to differ. A simple satellite phone would do nicely. They are small enough to easily be taken on as hand luggage.
Utter nonsense.
Have you ever tried to use a satellite phone inside of a vehicle ? I have, and you can hardly establish a viable network connection, let alone make a phone call unless you have an external antenna connection, which, lets face it, they are very very very unlikely to have had on a 777 !