Let’s start with the Inmarsat IsatPhonePro. It is the newest handheld satellite on the market which was launched June of 2010.
The Inmarsat IsatPhonePro uses three geostationary I-4 satellites that provide overlapping everywhere on the planet usage, excluding only the Polar Regions. The three I-4 satellites provide voice and data service for both the IsatPhonePro and the BGAN satellite terminal.
The small easy to use IsatPhonePro is back up with Inmarsat rock solid reputation for quality service.
The Inmarsat-4 constellation has power enough to generate hundreds of high powered spot beams to the majority of the planet.
Each satellite can generate more than 200 narrow spot beams and 19 wide beams. These Beams can quickly be focused anywhere on earth to provide extra capacity when demanded by natural disasters or military conflicts.
The I-4 satellites powerful features include: a very large body, Solar arrays with an immense wing span of 45 meters, a digital signal processor controls the beam forming the antennas and the channel allocation and the 9 meter wide reflector when deployed unfurls in orbit like a giant flower. There are both chemical and plasma ion thrusters that keep the satellite in its geostationary orbit.The Inmarsat I-4 Story
The Iridium satellite phone uses a constellation of 66 low earth orbiting satellites that have polar orbits. This allows Iridium to provide the only truly global satellite voice and data coverage which includes the poles.
One of the reasons Iridium works so well is their system has more satellites than any other satellite provider, giving coverage to every part of the planet. With no service gaps, Iridium users can place and receive calls from virtually every part of the planet as long as they have line-of-site to one of the satellites.
The Globalstar satellite phone uses a constellation of 40 low earth orbiting satellites. Globalstar provides global regional voice and data service to over 120 countries on the planet.
The Globalstar constellation orbits at an altitude of approximately 1,500 kilometers of (876 miles). First generation Globalstar satellite weighed 550 kg. Their second generation satellites will weigh substantially more. Because of this and the fact the satellites lack inter satellite linking the constellation picks up signals from over 80% of the planet excluding the extreme polar regions and some ocean regions.
The satellites are simple repeaters or mirrors in the sky. Globalstar calls this “bent pipe” technology. Voice and data transmissions come up from the satellite phone or data device to one of the 40 satellites, that signal is then bounced back down to one of the ground gateways where it is transferred to the public switched telephone network and/or the Internet.