When ships are at sea, most sailors want to maintain the communication services they are accustomed to e.g. using land - telephony and data/Internet.
This is made possible by satellite communications services - such as Inmarsat's FleetBroadband service or by VSAT-based satellite services.
Inmarsat deliver data services that include voice and data rates of up to 432 kilobits per second. VSAT-based services can deliver higher data speeds. The VSAT equipment is typically larger than Inmarsat's FleetBroadband terminals.
Coverage
In terms of coverage, the Inmarsat FleetBroadband service is almost providing a global coverage. (70 Degrees North to 70 degrees South)
The VSAT solutions provide limited global coverage - a fact there are undergoing changes since the number of planned satellite for VSAT service is increasing.
Neither systems cover the North or South Pole respectively - the coverage is at about 70 degrees North / South. The satellites which for these two types of systems are geostationary are positioned over the Equator at approx. 36.000 km altitude and due to the distance they can not provide coverage of North and South Pole.
There are major differences in the accounting terms and conditions between the two systems. Inmarsat FleetBroadband system is 'pay by usage' - meaning that you pay for the data volume sent/received via the satellite or the telephone. The VSAT system is accounted as a fixed monthly fee. This means that you always know the fee per Month independently of how much you utilize the terminal.
Telephony over the VSAT system can be supplied as a so called VoIP solution (voice over IP) - to very favorable prices, which are billed separately.