The calls that I recall being reported on used telephones available to flight crew for communications unrelated to flight and possibly made available for crazy prices to passengers.
You generally can't receive cell phone signal at segment of airliner flight except immediately after takeoff and in final stages of landing, due to optimizations involved in providing said signal (directional segment antennas, with attempts to beam-form towards specific terminals in latest versions). In practice I had hard time and required special tricks to keep a call running above 500m AGL and it probably depended on BTS located on hill above my reference point.
You generally can't receive cell phone signal at segment of airliner flight except immediately after takeoff and in final stages of landing, due to optimizations involved in providing said signal (directional segment antennas, with attempts to beam-form towards specific terminals in latest versions). In practice I had hard time and required special tricks to keep a call running above 500m AGL and it probably depended on BTS located on hill above my reference point.