This type of alert is of the lowest priority. This is the most common type of alert used for contacting another vessel, for setting up and establishment of a voice communication public correspondence link call via a CRS to a subscriber ashore using a duplex working channel, etc.

Public correspondence on MF frequencies

International and national DSC channels separate from the DSC distress and safety calling channel 2187.5 kHz are used for digital selective-calling on MF for public correspondence.
Ships calling a coast station by DSC on MF for public correspondence should preferably use the coast station's national DSC channel.
The international DSC channel for public correspondence may as a general rule be used between ships and coast stations of different nationality. The ships transmitting frequency is 2189.5 kHz, and the receiving frequency is 2177 kHz.
The frequency 2177 kHz is also used for digital selective-calling between ships for general communication.

Transmission of a DSC call for public correspondence to a coast station or another ship

A DSC call for public correspondence to a coast station or another ship is transmitted as follows:
  1. tune the transmitter to the relevant DSC channel;
  2. select the format for calling a specific station on the DSC equipment;
  3. key in or select on the DSC equipment keyboard:
  • the 9-digit identity of the station to be called,
  • the category of the call (routine),
  • the type of the subsequent communication (normally radiotelephony),
  • a proposed working channel if calling another ship (a proposal for a working channel should NOT be included in calls to a coast station; the coast station will in its DSC acknowledgment indicate a vacant working channel, in accordance with the DSC equipment manufacturer's instructions),
4. transmit the DSC call.

After broadcasting the Routine Alert on DSC and receiving the acknowledgment on DSC, voice communication continues on a MF working channel indicated in the DSC acknowledgement from the individual vessel or CRS.

(MMSI of the called station spoken 1 to 3 times) and/or (Name of the called station spoken 1 to 3 times) and/or (Call sign of the called station spoken 1 to 3 times)

THIS IS (Name of the calling station spoken 1 to 3 times) and/or (Call sign of the calling station spoken 1 to 3 times) and/or (MMSI of the calling station spoken 1 to 3 times)

(Message)

OVER
Pattern of a Routine Call and Message

Lyngby Radio Lyngby Radio Lyngby Radio

THIS IS Spinaker, Spinaker, Spinaker, code sign Sierra 5 Lima 1 2, 278054321

Request link call to subscriber +44 1253 779123

OVER
An example of a Routine Call and Message

Calling a coast station

Transmission of a DSC call on MF/HF takes approx. 8 seconds. The Coast station if able to comply will answer the call within 4½ minutes by sending a DSC Acknowledgement containing information on working frequencies for the subsequent traffic. When acknowledgement is received lift the handset to set the radio to the working frequencies.
If no acknowledgement is received within 5 minutes, the equipment returns to the previous telephony display and starts scanning if selected.

If a phone number was included in the call then immediately after reception of the acknowledgement the DSC call is repeated on the working frequency. This call may be used by the coast station for channel quality evaluation. If the channel quality evaluation indicates that communication will be satisfactory, the coast station sends a DSC acknowledgement and starts dialing the subscriber number. Dialing tones may be heard in the speaker or handset.
When the handset is placed on hook after a Direct Dial call a DSC call indicating ‘End of call’ is send to terminate the connection. The coast station may respond with a DSC call indicating the chargeable duration of the connection.

Practice on MF/HF radio simulator

  1. Press the Menu button and select DSC CALL
  2. Select COAST STATION (SHORE) call type
  3. Some coast stations provide automatic connection with the public switched telephonenetwork. To use this facility select PHONE NO and key in the telephone number. Otherwise: Key in the nine digit MMSI number of the wanted coast station.
  4. If the MMSI number is found in the station list, the frequencies are selected from the DSC frequencies of the station if any; otherwise from the list of non distress DSC frequencies. If DSC frequencies were selected from the Telephony display prior to the call these are default. Distress frequencies cannot be selected in any way.
  5. Starts transmission of the call



Calling a ship

Transmission of a DSC call on MF/HF takes approx. 8 seconds. The called ship is supposed to answer the call within 4½ minutes by sending a DSC Acknowledgement containing information on working frequencies for the subsequent traffic. When acknowledgement is received lift the handset to set the radio to the working frequencies.
If no acknowledgement is received within 5 minutes, the equipment returns to the previous telephony display and starts scanning if selected.

Practice on MF/HF radio simulator

  1. Press the Menu button and select DSC CALL.
  2. Select SHIP call type
  3. Key in the nine digit MMSI number of the wanted ship.
  4. Selects telephony display for change of working frequencies
  5. Insert the working frequencies in the call
  6. Select the DSC frequency. Normally 2177 kHz is used for intership DSC calls. Distress frequencies cannot be selected in any way.
  7. Starts transmission of the call




Follow with voice communication on working channel indicated in the DSC acknowledgment.

Repeating a call

A DSC call for public correspondence may be repeated on the same or another DSC channel, if no acknowledgment is received within 5 min.
Further call attempts should be delayed at least 15 min, if acknowledgment is still not received.

Reception of a Routine Alert

When the transceiver is not used for traffic, scanning should be activated to keep watch on one or more DSC frequencies used for public correspondence and general ship-to-ship communication. Reception of an individual routine call addressed to the ship is indicated by a sound signal.
On receipt of a DSC call from a coast station or another ship, a DSC acknowledgment is transmitted as follows:
  1. tune the transmitter to the transmit frequency of the DSC channel on which the call was received,
  2. select the acknowledgment format on the DSC equipment,
  3. transmit an acknowledgment indicating whether the ship is able to communicate as proposed in the call (type of. communication and working frequency),
  4. if able to communicate as indicated, tune the transmitter and the radiotelephony receiver to the indicated working frequencies and prepare to receive the traffic.

Practice on MF/HF radio simulator

  1. Stops alarm sound.
  2. Displays the contents of the call.
  3. Press ACK or lift handset. The call should be answered by sending a DSC Acknowledgement within 4½ minutes. LIFT HANDSET TO ACKNOWLEDGE and ACK is shown if SSB telephony and legal frequencies are indicated in the call. Lifting the handset or pressing the softkey in this case will initiate transmission of an acknowledgement containing the mode and frequencies from the received call.
  4. Transmission of the DSC acknowledgement takes approx. 8 seconds. Then the equipment is automatically set to the mode and working frequencies from the acknowledgement and voice communication can start.
  5. When handset is placed on hook the equipment returns to previous telephony setting.



Direct Dial Calls

Some coast stations provide automatic connection from the public switched telephone network allowing a telephone subscriber to call the ship directly without operator intervention at the coast station.
Note: Auto Acknowledgement must be On to allow automatic connection, see DSC Status Display.
An acknowledgement is initiated immediately when a Direct Dial call is received. The handset should be lifted off hook within 1 minute which will initiate a DSC call on the working frequency. This call is used by the coast station for channel quality evaluation. When acknowledgement is received telephone conversation can start.
When the handset is placed on hook after a Direct Dial call a DSC call indicating ‘End of call’ is send to terminate the connection. The coast station may respond with a DSC Call indicating the chargeable duration of the connection.

After the reception of a Routine Alert you can:
  • Accept and answer the call by sending an acknowledge.
  • Not accept the call: Press key C to cancel ringing and clearing the display.

Testing the equipment used for distress and safety

Testing on the exclusive DSC distress and safety calling frequency 2 187.5 kHz should be avoided as far as possible by using other methods.
UNDER NO CIRCUMSTANCES SHALL A DSC DISTRESS ALERT BE SENT TO TEST YOUR RADIO. IT IS A VIOLATION OF THE RULES AND CAN RESULT IN HEAVY FINES.
Please consult your owner's manual for the proper operation.
Testing should be executed once a week.

Practice on MF/HF radio simulator

  1. Press the Menu button and select DSC CALL
  2. Select COAST STATION (SHORE) call type
  3. Key in the nine digit MMSI number of the nearest coast station which can accept and reply to DSC test calls.
  4. Select the DSC frequencies
  5. Start transmission of the call
  6. Transmission of a DSC call on MF/HF takes approx. 8 seconds. The coast station should answer the call by sending a DSC Acknowledgement within 4 1/2 minutes. No further communication is intended to take place.
  7. Displays the contents of the acknowledgement.



Public correspondence on HF frequencies

The procedures for DSC communication for public correspondence on HF are the same as for MF.
Propagation characteristics should be taken into account when making DSC communication on HF.
International and national HF DSC channels different from those used for DSC for distress and safety purposes are used for DSC for public correspondence.
Ships calling a HF coast station by DSC for public correspondence should preferably use the coast station's national DSC calling channel.
Testing the equipment used for distress and safety on HF
The procedure for testing the ship's equipment used for DSC distress, urgency and safety calls on HF by transmitting DSC test calls on HF DSC distress channels is the same as for testing on the MF DSC distress frequency 2187.5 kHz.