Inmarsat GSPS or Global Satellite Phone Service is rapidly becoming the standard handheld satellite phone for users operating between 50° N and 50° S latitude. The main reason for this is the remarkable ability of the handheld IsatPhone 2 to reliably make long duration calls.
Docking stations and external antennas are availability for vehicular, in-building, and marine applications.
Inmarsat uses geostationary equatorial satellites to provide near global coverage except in the polar regions. Inmarsat GSPS offers voice calling, short messaging (SMS), email-to-text, and 2400 bps data. Single button press SOS functionality and automated GPS location tracking are available on some phone models.
Outfitter Satellite recommends Inmarsat GSPS for use inside the region indicated by the solid-gold-line (20° elevation angle relative to the horizon). Outside this region mountains and trees can easily block a low-lying satellite. Users is in extremely mountainous areas should verify whether the Inmarsat satellite is visible from their expected location before traveling.