Broadcasting and receiving DSC Alerts is one of the major facilities on a MF/HF radio that is made possible by the MF/HF DSC controller. DSC alerts are used to “switch people on” to follow on with voice communication.
DSC is used for a number of reasons and these are:
The types of DSC alerts are related to a particular category or priority.
Categories (priorities) of DSC Alerts (Why are we calling):
DSC alerts are classified according to their priority indicated below and in decreasing order:
Once the alert has been accepted or acknowledged by DSC, the equivalent of lifting a normal telephone receiver, you use your voice on the radio in the normal way.
If the alert is not acknowledged for whatever reason, it remains unanswered but the details will be stored in the memory or log of received alerts.
DSC is used for a number of reasons and these are:
- Automatic rather than manual radio watch keeping is available.
- Alerts using DSC are very quick (about 0.5 seconds on the dedicated frequency on marine VHF band, and 6-7 seconds on the dedicated frequency on marine MF/HF band) and do not occupy as much time as a manual voice call. This is very important particulary in areas where radiotelephone channels are often occupied.
- Distress alerting can be enabled quickly with one press of the “Distress” push button.
- Various categories of alert are available with the following order of priority: Distress, Urgency, Safety and Routine.
- ALL SHIPS – an alert to all ships within MF/HF range of the station sending the alert
- INDIVIDUAL – an alert addressed to one radio station within MF/HF range
- GROUP – an alert addressed to all those vessels having the group MMSI within MF/HF range
- GEO – an alert is sent to all stations within specified geographical area
The types of DSC alerts are related to a particular category or priority.
Categories (priorities) of DSC Alerts (Why are we calling):
DSC alerts are classified according to their priority indicated below and in decreasing order:
- DISTRESS – indicates that a person or a ship is in grave and imminent danger and requires immediate assistance (the highest priority usually broadcast to all stations)
- URGENCY – indicates an urgent call concerning the safety of a person or vehicle (can be broadcast to all ships, a geographical area or to an individual station)
- SAFETY – indicates a call concerning MSI (Maritime Safety Information), for example, meteorological forecast/broadcast or navigational warning (can be broadcast to all ships, a geographical area or to an individual station)
- ROUTINE – indicates a call at the lowest priority concerning routine communication, for example, setting up of an RT link call via a CRS to a shore-based subscriber (normally broadcast to all ships or to an individual station)
Once the alert has been accepted or acknowledged by DSC, the equivalent of lifting a normal telephone receiver, you use your voice on the radio in the normal way.
If the alert is not acknowledged for whatever reason, it remains unanswered but the details will be stored in the memory or log of received alerts.
Last modified: Saturday, 25 April 2020, 7:50 PM