Long Range Certificate Course

Digital Selective Calling - Broadcasting and receiving DSC Alerts is one of the major facilities on a VHF radio that is made possible by the VHF DSC controller. DSC alerts are used to “switch people on” to follow on with voice communication.

DTE, Data Terminal Equipment is an end instrument that converts user information into signals or reconverts received signals.

Duplex channels are normally only used for communication between vessels and CRS and for port operations and ship movement. With duplex channels our transmission can only be heard by the CRS. However, all ship stations listening to the same channel can hear the CRS transmission.

EGC, enhanced group call transmitted via the Inmarsat C system. The messages which are broadcast via this system are FleetNET or SafetyNET messages. The SafetyNET messages are used for transmission of MSI for areas outside the range of the NAVTEX stations within the coverage of Inmarsat satellites.

Emergency Position Indicating Radio Beacon - It is used as a distress alerting system, indicating to SAR authorities both the identity and position of a person or a vessel, which is in grave and imminent danger and requires immediate assistance.

Forward Error Correction, telex mode used to send mainly priority message (distress, urgency or safety) from one transmitter to many receivers

FleetNET are messages addressed to a dedicated group of mobile stations such as all ships from the same company or all ships from the same country (having the same nationality) transmitted via the Inmarsat C EGC system.

Global Maritime Distress and Safety System - The GMDSS is an important part of the IMO (International Maritime Organisation) SOLAS (Safety Of Life At Sea) convention. It is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships.

Global Positioning System - Utilizing a constellation of at least 24 Medium Earth Orbit satellites that transmit precise microwave signals, the system enables a GPS receiver to determine its location, speed, direction, and time. GPS receivers may be found also on ships, for example as a part of navigational equipment and in some models of EPIRBs. They are usually connected to DSC radio communication equipment, for example VHF radio.

Gross Tonnage - Size of the ship, calculated as a function of the volume of all ship's enclosed spaces.