Sat-aero-c, Sat-b – Wavecom W74PC V8.7.0 User Manual

Page 238

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Transmission Modes

WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0

AERO frequencies are in the range between 1545 MHz and 1547 MHz on the L-band and between 3685
MHz and 3687 MHz on the C-band. DPSK P channels with 600 or 1200 bps can be found around 1545
MHz, whereas the faster OQPSK channels with 10500 bps are found around 1546 MHz.

SAT-AERO-C

The SAT-AERO-C mode decodes the circuit switched traffic channels. There are two bit-rates: 8400 bps
and 21000 bps.

In the 8400 bps mode only the raw AMBE data is decoded and saved. Speech decoding is not supported.

In the 21000 bps mode, speech is decoded and saved into .wav files. Live voice is output to the speaker at
the same time. The data files are saved into the DATA-OUTPUT folder.

SAT-B

The SAT-B system carries digital voice, low and high speed data and telex. The forward direction channels
from land earth stations (LES or CES) to mobile earth stations (SES or MES) are 6 kBaud, 12 kBaud and
65.1 kBaud TDM or SCPC depending on service.

Parameter

Value

Frequency range

L-Band/C-Band

Operation modes, symbol rate, modu-

lation

Inm-B (Forward NCS and LES Msg Chnl)

Forward:

6 kbps DPSK, NCS TDM, LES TDM

24 kbps OQPSK, CES Voice, CES Low Speed Data

132 kbps OQPSK, CES High Speed Data

Return:

24 kbps OQPSK, Aloha, TDMA, SCPC

Required SNR

>15 dB (20 dB recommended)

Input format(s)

IF

In idle mode all mobile stations listen to the NCS (Network Control Station) common TDM channel, which
carries signaling information. When a mobile station identifies its id in a signaling frame it will act on the
commands received from the NCS and in case of a channel assignment message being received tune to
the assigned transmit-receive frequency pair. The forward telex traffic channel (from the LES) is also a
TDM with the same frame structure as the NCS TDM.

The return channels are all 12 kBaud Aloha for SES requests, call acknowledgements and registration traf-
fic, TDMA for SES response and telex traffic, and SCPC for SES voice, low and high speed data.

64 kbs is only decoded with W-CODE.

WAVECOM software decodes SAT-B fax with 9.6 kbps and low speed synchronous data with 9.6 kbs. The
decoder will automatically adjust to the modulation type in use (BPSK or OQPSK).

All SAT Modes store the monitor information in a result file. The list of all result files is displayed in the
lower part of the User Interface. The file names are constructed with the Date/Time and possibly addition-
al information.

Additional information:

See

SAT Settings…

on page 43.

See

SAT System

on page 291.

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