An Introduction to Satellite Communications

Within the maritime context, satellite communication technology has been used as a means to enable long distance telephony and connect to the Internet via broadband data connections. This can be very useful for users who are located in remote areas, and cannot access a broadband connection, or require high availability of services.

A Short History of Maritime Satellite Communications

In 1970, Inmarsat, a non-profit organisation was established by the IMO to provide a satellite communications network for the maritime industry. Basic voice and telex communication was enabled onboard thanks to the Inmarsat A terminal (the service was later withdrawn in 2007). Early Inmarsat services were categorised by an alphabetical reference according to their progression, meaning Inmarsat A, B, C, D and E. When the service corresponding with the letter F was reached, the product was renamed to Inmarsat Fleet, followed by a number to indicate the size of the antenna (Fleet 33, 55 and 77). (Ref:

Since the arrival of GMDSS and the mandatory requirement for ships to be fitted with at least an Inmarsat C terminal, maritime satellite communications has continued to grow, as emailing onboard became an accepted communication standard. In 2005 Inmarsat became a private company. Because of its role in the birth of GMDSS, subsequently, Inmarsat went on to be strong in the marine satellite sector but was not without its competition from Iridium Communications.

The provision of GMDSS is now open to other satellite operators and further to an application to the IMO in April 2014, Iridium Communications could be determined as a second provider of GMDSS by the end of 2015.


Today satellite (or mobile) communications services can mostly be defined as one of two categories, VSAT and MSS. Both Mobile Satellite Services (MSS) and VSAT (Very Small Aperture Terminals) provide two-way voice and data communications via satellite to users who are on the go or in remote locations.

Inmarsat, Iridium and Thuraya offer popular MSS solutions, including Inmarsat FleetBroadband and Iridium OpenPort, which feature lower cost equipment and typically incremental costs for usage, either charged by the minute or by megabyte; or monthly allowances.

VSAT services usually use a larger stabilised antenna within a dome and require a more significant commitment when it comes to installation, but the cost of usage is typically included within a single fixed monthly price. VSAT is also associated with higher bandwidth levels so is suited to users requiring a higher volume of phone or Internet traffic.


What is Maritime VSAT