GMDSS Digital Selective Calling

Global Maritime Distress and Safety System's Digital Selective Calling

Frequencies	2.1875 MHz,4.2075 MHz,6.312 MHz,8.4145 MHz,12.577 MHz,16.8045 MHz,2.177 MHz,156.525 MHz
Frequency Range	2.177 MHz - 156.525 MHz
Mode	USB
Modulation	FSK
ACF	—
Emission Designator	—
Bandwidth	350 Hz
Location	Worldwide
Short Description	Global Maritime Distress and Safety System's Digital Selective Calling (GMDSS-DSC) is a maritime communication protocol intended to initiate ship-to-ship, ship-to-shore and shore-to-ship radiotelephone and MF/HF radiotelex calls.
I/Q Raw Recording	—
Audio Sample

Global Maritime Distress and Safety System's Digital Selective Calling System is a maritime communication protocol using FSKFrequency-Shift Keying, quite similar to SITOR and used on VHFVery High Frequency (30-300 MHz), MFMedium Frequency (300-3000 kHz) and HFHigh Frequency (3-30 MHz) marine bands. The full description of the protocol is described in ITU document M 493 while a comprehensive description is given in this PDF file.Dead link

This mode is derived from the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 493-4 Selcall format.

Samples

HFHigh Frequency (3-30 MHz) DSC	VHFVery High Frequency (30-300 MHz) DSC

Additional Samples:

HFHigh Frequency (3-30 MHz) DSC:

Frequencies

VHFVery High Frequency (30-300 MHz) Calling and urgency
156.525 MHzMegaHertz (MHz) 10^6 Hz VHFVery High Frequency (30-300 MHz) Channel 70

MFMedium Frequency (300-3000 kHz)/HFHigh Frequency (3-30 MHz) Distress and urgency

• 2187.5 kHzKiloHertz (kHz) 10^3 Hz
• 4207.5 kHzKiloHertz (kHz) 10^3 Hz
• 6312 kHzKiloHertz (kHz) 10^3 Hz
• 8414.5 kHzKiloHertz (kHz) 10^3 Hz
• 12577 kHzKiloHertz (kHz) 10^3 Hz
• 16804.5 kHzKiloHertz (kHz) 10^3 Hz

MFMedium Frequency (300-3000 kHz)/HFHigh Frequency (3-30 MHz) Ship to ship calling frequencies

• 2177.0 kHzKiloHertz (kHz) 10^3 Hz
• 4208.0 kHzKiloHertz (kHz) 10^3 Hz
• 6312.5 kHzKiloHertz (kHz) 10^3 Hz
• 8415.0 kHzKiloHertz (kHz) 10^3 Hz
• 12577.5 kHzKiloHertz (kHz) 10^3 Hz
• 16805.0 kHzKiloHertz (kHz) 10^3 Hz
• 18898.5 kHzKiloHertz (kHz) 10^3 Hz
• 22374.5 kHzKiloHertz (kHz) 10^3 Hz
• 25208.5 kHzKiloHertz (kHz) 10^3 Hz

MFMedium Frequency (300-3000 kHz)/HFHigh Frequency (3-30 MHz) ship to shore duplex DSC channels (ship TXTransmit - ship RXReceive)

• 2189.5 - 2177.0 kHzKiloHertz (kHz) 10^3 Hz
• 4208 - 4219.5 kHzKiloHertz (kHz) 10^3 Hz
• 6312.5 - 6331.0 kHzKiloHertz (kHz) 10^3 Hz
• 8415.0 - 8436.5 kHzKiloHertz (kHz) 10^3 Hz
• 12577.5 - 12657.0 kHzKiloHertz (kHz) 10^3 Hz
• 16805.0 - 16903.0 kHzKiloHertz (kHz) 10^3 Hz
• 18898.5 - 19703.5 kHzKiloHertz (kHz) 10^3 Hz
• 22374.5 - 22444.0 kHzKiloHertz (kHz) 10^3 Hz

Decoding Software

Hobby Level Software

• DSC Decoder
• GMDSS Decoder for IPhone / Ipad
• MultiMode Cocoa
• MultiPSK
• SeaTTY
• Yet Another DSC Decoder (YADD), in the list of links to software
• SDRangel

Professional Equipment/Software

• go2DECODE
• go2MONITOR
• Hoka 300-32
• Wavecom W-Code
• Wavecom W-Spectra
• Rohde&Schwarz CA100

Additional Links

• These links come from the UDXF Website
  • Maritime ID Digits(MID) and Maritime Mobile Service Identity (MMSI) List
  • Maritime Safety Information List
  • Maritime SelCalls
• General Information on Digital Selective Calling
• GMDSS Information
• Wikipedia DSC
• RadioRaft GMDSS-DSC
• MultiPSK GMDSS DCS
• WAVECOM Decoder Online Help

Additional Images