The Globalstar network was developed specifically with the business traveler in mind. They envisioned their customers as people who were working on the fringes of cellular networks, crossing in and out of coverage areas. Therefore they designed a compact tri-band handset that would work on both the cellular AMPS and CDMA networks and, the Globalstar network of 48 Low Earth Orbiting satellites. These satellites orbit the Earth at an altitude of 875 miles.
The phones are designed to switch seamlessly between the cellular networks and the satellite network, even during a call. The phone will always use the cellular networks if available. Only when these are not available will they link to the satellite network. By using this method the idea was to offer the best cost effective service, you would only use the more expensive satellite service when there was no alternative.
The downside of the Globalstar system is its coverage area. By operating on the AMPS and CDMA standards they have limited themselves to the localities where those standards are supported. At the moment this includes the Americas, Russia, and parts of Asia. Likewise their satellite network coverage area is limited compared to those of its rivals. They can only offer service in about 100 countries, their territorial waters and some mid ocean waters.
Globalstar, like Inmarsat have developed their data and fax transfer capabilities, using a laptop or PDA (Personal Digital Assistant) email and Internet access are possible, but like their voice service, they can only offer limited coverage.
They also share the same problem as Iridium in that there is a higher risk of loosing signals due to the need to send them via a number of satellites before connecting them with their destination.