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Transmission Modes WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V9.1.0
AX.25 layer 3 implemented
Compressed TCP/IP packet. Van Jacobson (RFC 1144)
Uncompressed TCP/IP packet. Van Jacobson (RFC 1144)
No layer 3 protocol implemented
Escape character. Next octet contains more Level 3 protocol information
Escape character. Next octet contains more Level 3 protocol information.
RUM-FEC
164.5 and 218.3 Bd, variable 30-650 Bd
RUM-FEC operates at symbol rates of 164.5 and 218.3 Bd on the radio link.
The HNG-FEC and RUM-FEC modes are technically very similar. RUM-FEC alphabet has a codeword length
of 16 bits where each of the 32 used bit combinations corresponds to an ITA-2 character.
The RUM-FEC alphabet is designed to obtain a maximum Hamming distance for error detection and has
deep interleaving. The actual ITA-2 alphabet is not contained in the code table. As in HNG-FEC error cor-
rection is performed by table look-up of the bit pattern (character) closest resembling the character in er-
ror.
RUM-FEC has a bit interleaving of 128 bits, each new character starting at intervals of 16 bits. The soft-
ware synchronizes to traffic as well as idle bit patterns.
Error correction may be enabled or disabled using the ECC item in the Options menu.
In RUM-FEC mode the signal polarity (sideband) can be manually selected by toggling the Polarity item in
the Demodulator menu. If polarity changes during a transmission, synchronization will not be lost.
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