Wavecom W74PC V8.7.0 - Manual (Page 246)

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Transmission Modes WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0
Parameter Value
Frequency range C-Band
Operation modes Inm-mM (Return Msg Chnl)
Modulation QAM16
Symbol rate 33600 Bd
Required SNR > 20 dB (25 dB recommended)
Input format(s) IF
Unlike the other SAT modes, this mode does not automatically select a frequency. The user has to manu-
ally set the frequency and offset to the desired signal, which will then not be interfered with or changed by
the decoder (mode). The signal level should be at least 20 dB over the noise, a 25 dB level will deliver
good results.
Session start and end are automatically recognized, but if the signal is too weak, meaningful sessions will
not be decoded and consequently a session file will not be generated, even if some intermediate decoding
has occurred.
The following services are decoded:
 ISDN
Operation
With the help of the FFT-Analysis-Tool look for a SAT-MINI-M-HSD signal (bandwidth 40 kHz, QAM16 33.6
kSymbol/sec) with a lot of traffic.
In the Satellite mode menu choose Inmarsat, SAT-MINI-M-C-HSD.
The Session Window displays the start and end of a session. The “MES_ID” displayed is the return MESId
of the MES (Mobile Earth Station); the “Frequency” is a dummy value.
The Session List Window displays the results of the successfully decoded sessions. The decoded data is
saved as “Hsd.txt”.
Additional information:
See “ SAT Settings… ” on page 43.
See “ SAT System ” on page 291.
SI-ARQ
SI-ARQ is a simplex system similar to for example SITOR. SI-ARQ therefore also sounds similar to the
well-known SITOR system. Because data and pause blocks are longer in duration, the perception of a low-
er baud rate is created.
Parameter Value
Frequency range HF
Operation modes Simplex ARQ
Modulation FSK
Symbol rate 96.0, 192.0 and 200.0 Bd
Receiver settings DATA, CW, LSB or USB
Input format(s) AF, IF
Additional Info ITA-3
SI-ARQ operates at symbol rates of 96, 192 or 200 Bd on the radio link.