Actually cell phones are only prohibited in US and maybe a few others airspace! There's a fully Boeing/airbus supported and tested solution called aeromobile and on air in which a gsm pico cell is on board and connected to a satellite. There is also mobile data although this is only edge speeds at the moment. BA and Virgin Atlantic have it on some aircraft over the Atlantic and the system is auto shutoff during taxi takeoff and in and near us airspace. It is essentially an international gsm roaming service and the only us Sim cards supported are at&t and T-Mobile.