Ole.
that's for a handset - a phone - which has data capability, but at a very low bit rate.
the isatphone is a relatively new product - 5 years..?
Most other Inmarsat products have directional antennas
but even if they were using an Inmarsat product without a directional antenna, the antenna still probably had a GPS, and the location could be transmitted in the "ping", without any need to get the location from other instruments on the aircraft