Wavecom W40PC, Manual

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WAVECOM Decoders v6.15 W40PC, W41PC, W51PC Transmission Modes
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149
Federal 1
Baden – Wuerttemberg 2
Bavaria I 3
Berlin 4
Bremen 5
Hamburg 6
Hessen 7
Lower Saxony 8
Nordrhein-Westfalen 9
Rheinland-Pfalz a
Schleswig-Holstein b
Saarland c
Bavaria II d
Lower Saxony II e
The
location identifier
(e.g. OK 10) can assume one of 99 different possibilities. The actual
value is determined by each individual state.
The field for the vehicle number (e.g. 4213) can contain one of 9999 combinations. The
individual call signs are assigned by each specific service.
The status field contains the actual information. A maximum of 16 different messages may
be transmitted. A distinction between messages from vehicle to control and control to vehicle
must be made. For example a mobile-to-control message containing the digit “0” may trigger
an emergency call. The same message in the opposite direction i.e. control to vehicle, may
imply a status request.
The last field ( special use ) is mapped to 4 bits in the telegram and serves to communicate
the equipment state, directional and abbreviated tactical information.
GMDSS/DSC-HF
Frequency range HF
System SELCAL Digital
Baudrate 100.0 Baud
Modulation SSB or DIRECT-FSK
Shift 170 Hz
Receiver settings CW, LSB or USB
Signal source(s) AF, HF or IF
Alphabet ITA-5
GMDSS means G lobal M aritime D istress and S afety S ystem and is a worldwide system for
handling maritime emergency and safety transmissions. Part of the whole system is the DSC
(Digital Selective Calling). Each user of the GMDSS gets a nine-digit number (MMSI –
Maritime Mobile Service Identity) from the mobile maritime service. 3 digits of this number
are used as a country code.
DSC is used on HF and VHF. On HF the system is working with 100 baud and a shift of 170
Hz. On VHF the speed is 1200 baud and the tones are located at 1300 Hz and 2100 Hz (Center
1700 Hz).
The complex structures of the DSC are described in detail in the ITU-Rec. 493-0.