Global Mobile Satellite System
The Global Mobile Satellite System (GMSS) consists of several satellite phone providers serving private customers. It can be compared to PLMN (wireless telephony carriers) and PSTN (traditional wire-based telephony).
As of 2008, ranges of numbers have been assigned to four GMSS carriers:
- Iridium Satellite LLC
- Ellipso (a non-operational service, with no satellites launched)
- ICO Global Communications
In 1996, the ITU introduced country code +881 for direct international dialing of phones on GMSS providers. (Inmarsat had already been allocated country code +870.) The next digit following the country code is allocated (two at a time) to a particular GMSS carrier:
Satellite numbers outside the GMSS country code
Inmarsat is a satellite-based communications provider, but it is primarily a maritime service and is not generally considered part of the GMSS.
Globalstar usually allocates subscribers with a local number in the country they are based rather than using their GMSS country code.
Iridium also uses an Arizona-based access number to call Iridium phones for those unwilling or unable to call the usually expensive GMSS number directly.