Inmarsat C

Inmarsat C is a digital satellite communication system whereby anything that can be encoded into digital format, whether text, numeric data from instruments or other information in digital form, can be sent and received over the system.

Inmarsat Mini C is a new family of compact mobile terminals, which support two-way store-and-forward communication via lightweight, low-cost and low-power consumption terminals.
Depending on the model, Inmarsat Mini C terminals support the same communication functions as Inmarsat C terminals.

The typical Inmarsat C and Mini C terminal includes a small omni-directional antenna, transceiver (transmitter and receiver), messaging unit and power supply (may be powered from a battery only).

The following communications services are available via the Inmarsat C:

If there is no time to change (update) certain information on the distress alert menu on your Inmarsat C or Mini C terminal, you can send a distress alert simply by pressing and holding the dedicated distress button for the required number of seconds (usually five seconds).

The Inmarsat C system can be used for sending different types of store-and-forward messages in ship-to-shore, shore-to-ship and ship-to-ship direction including:

Your Inmarsat C or Mini C terminal can communicate using a variety of two-way messaging and data services available via Inmarsat C system, providing that the following conditions are met:

The addressed Land Earth Station (LESs) sends confirmation messages at two levels:

The GMDSS was implemented from 1 February, 1992, and marked the most important change in maritime safety since the advent of radio in 1899. The GMDSS became fully operational on 1 February, 1999.

Inmarsat provides the space segment necessary for instant and reliable distress and safety satellite communications for the maritime community.

The International Maritime Organisation (IMO), the international body that oversees the regulation of ships at sea, requires that every Inmarsat C terminal that operates under of the Global Maritime Distress and Safety System (GMDSS), if installed on or after 23 November, 1996, shall conform to 'Performance standards for Inmarsat C ship earth stations capable of transmitting and receiving direct-printing communications' as per IMO Resolution A807(19).

Inmarsat C terminals suitable for use in a GMDSS installation (PDF)

Inmarsat Mini C terminals are is a smaller and lighter version of Inmarsat C terminals. Mini C terminals offer the same communication services as an Inmarsat C: two-way store-and-forward data and messaging via a lightweight, low-cost terminal.

Value-added services are provided by some Land Earth Station Operators (LESOs) and include:

It is possible to send a message from an Inmarsat C or Mini C terminal to email addresses all over the world. All maritime terminals support this service.

It is possible to send messages from Inmarsat C and Mini C terminals to special services offered by land earth stations by using special two-digit codes.

FleetNET is the international commercial service offered under Inmarsat C's ECG capabilty, which allows authorised information providers, such as commercial subscription services, shipping companies or governments to broadcast messages to selected groups of vessels, each of which has registered with the information provider and been added to a FleetNET closed group / network.

SafetyNET is an international safety service made possible by Inmarsat C Enhanced Group Call (EGC) capability, which allows authorised maritime safety information (MSI) providers, such as meteorological offices, hydrographic officers and MRCCs to broadcast messages to all ships in certain geographical areas.