Mobile phones have long been banned on commercial aircraft amid fears they would interfere with the navigation system and control of the plane, an issue the aviation industry has debated at length. Concerns centred on mobiles logging on to terrestrial networks from the air.

However, the system pioneered by OnAir will have an airborne transmitter with a lightweight GSM pico-cell network, located on the aircraft itself, in an attempt to ensure mobiles operate at lower transmission power than if trying to find a mast, thereby avoiding possible interference.

"Even if all 189 people on the aircraft had their phones switched on, the power output would only be 189 milliwatts, which is way below a level that could interfere with aircraft," Mr Cooper said. "The power is also not sufficient to accidentally connect to a ground network." The substation on the aircraft is connected to a cable that runs above the ceiling of the plane. When a voice call goes from the cable to the substation, it connects to an aircraft server that manages the whole system and supports communication with a satellite. The satellite is linked to a ground infrastructure interconnection run by Monaco Telecom, which directs the call to ground public networks and home operators.

The airspace in the cabin is treated as a virtual country, with the mobile user "roaming" onto that system and paying a premium tied to international roaming charges. Mr Cooper expects charges to decline over the coming years as more airlines use the service.