Furuno FS-5070 manual DSC Overview, What is DSC?, DSC Message, Call Description

3.DSC OVERVIEW

3.1What is DSC?

DSC is an acronym meaning Digital Selective Calling. It is a digital distress and general calling system in the MF and HF bands used by ships for transmitting distress alerts and general calls and by coast stations for transmitting the associated acknowledgements.

For DSC distress and safety calling in the MF and HF bands, the frequencies are 2187.5, 4207.5, 6312.0, 8414.5, 12577.0, and 16804.5 kHz.

The DSC station sends and receives DSC general and distress calls via the radiotelephone.

Distress Frequency

Routine DSC Call

Option

TRANSCEIVER

UNIT

Routine DSC Calls

CONTROL UNIT

3.2DSC Message

DSC calls are roughly divided in two groups: distress, urgency and safety messages, and routine messages. Below are the types of DSC messages.

Call	Description
Distress Alerts	Your ship sends distress message
Distress relay area	Your ship relays distress call to all ships in a specific geographical area
Distress relay coast	Your ship relays distress call to a coast station
Medical Transport	Inform areas that your ship is carrying medical supplies*
Neutral Craft	Inform areas that your ship is not a participant in armed conflict*
Individual	Call to a specific address
PSTN message	Call over Public Switched Telephone Network (PSTN)
Test message	Send test signal to a station to test your station’s functionality
Group message	Call to a specific group
Area message	Call to all ships in a specific geographical area
Position	Your ship requests position of other ships
Polling message	Confirm if own ship is within communicating range with other ships.
	(Receive and answer only)

*Special Message: When sending these messages, set the acknowledgement. See section 6.15.

3-1