Icao Selcal - Wavecom W40PC Manual

Alphabet
HNG-FEC operates at a speed of 100.05 Baud on the radio link.
HNG-FEC uses a 15 bit code, the first 5 bits corresponding to the ITA-2 alphabet. The first and
last bits of this codeword are inverted (Inv, Nor, Nor, Nor, Nor, Inv). The remaining 10 bits are
used for error detection and correction. Error correction is done by table look up of the
character which closest matches the one that was received in error.
HNG-FEC employs bit spreading (interleaving) with a distance of 64 bits, each new character
starting at intervals of 15 bits. The software synchronizes to traffic as well as idle bit patterns.
The idle binary bit pattern is given by 110 100 110 010 011.
Transmission reliability for HNG-FEC is good with the code spread offering additional
immunity against burst errors.
HNG-FEC is started by clicking the "Auto" button or by selecting a "Baudrate" in the
"Demodulator" menu. By toggling the "ECC" item in the "Options" menu error correction
may be enabled or disabled.

ICAO SELCAL

Parameter
Frequency range
System
Tone duration
Modulation
Receiver settings
Signal source(s)
Annex10 ICAO selective calling was initially defined in 1985 using twelve tones (Tones "A" to "M" but
without tone "I"). In 1994 the ICAO calling system, also known as ANNEX10, was extended
with the additional tones "P", "Q", "R" and "S" and now operates with 16 tones.
The allocation of selective call addresses is exclusively managed by Aeronautical Radio, Inc.
ARINC (ICAO Designator Selcal Registry).
Each address consists of two pairs of tones, e.g. "AB-CD". Both pairs have a duration of 1000
ms. Between each pair an interval of 200 ms is inserted. ICAO Selcal is used on all frequency
bands (HF and VHF/UHF).
ICAO Selcal Tone Allocation
Designation
RED "A"
RED "B"
RED "C"
RED "D"
RED "E"
RED "F"
RED "G"
RED "H"
RED "J"
WAVECOM Decoders v6.15 W40PC, W41PC, W51PC
ITA-2 with 10 Bit redundancy
Value
HF
SELCAL Analog
1000 ms
SSB
CW, LSB or USB
AF, HF or IF
Frequency (Hz)
312.6
346.7
384.6
426.6
473.2
524.8
582.1
645.7
716.1
Transmission Modes • 155