General Information
DSC (Digital Selective Calling) is part of the GMDSS (Global Maritime Distress and Safety System). It provides automatically formatted distress alerts, urgency, safety and routine radio-telephone calls.
Usage:
§ Data communication over HF / VHF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation,
primary |
FM |
|
|
Number of tones |
2 |
|
|
Shift (Hz) |
800 |
|
|
Bandwidth (KHz) |
10 |
|
|
Symbol rate (Baud) |
1200 |
|
|
Coding |
Checksum |
|
Demodulator Settings |
Demodulator |
FSK 2,3,4 discr. |
|
|
Symbol rate (Bd) |
1200 |
|
|
SR tolerance (Bd) |
5 |
|
|
Modulation order |
2 |
|
|
Shift (Hz) |
800 |
|
|
Shift tolerance (Hz) |
20 |
|
|
Modem type |
Synchronous |
|
|
Min. burst length (s) |
0.300 |
|
|
Max. burst length (s) |
0.600 |
|
|
Min. pause length (s) |
0.100 |
|
Features |
Demodulation |
yes |
|
|
Recognition |
yes |
|
|
Decoding |
yes |
|
|
Automatic Polarity Adjustment VHF |
yes |
|
|
Combination with other modems (modem list) |
yes |
|
Tuning |
The tuning frequency is the center of the signal. | |
|
Frequencies |
156.525 MHz | |
Table 8: DSC VHF
Figure 6: DSC VHF Spectrogram