Wavecom W61PC V7.5.0 - Manual (Page 126)

116  Transmission Modes WAVECOM Decoder W61PC/LAN Manual V7.5
Code Country Code Country Code Country
Y Romania O Slovak Rep. H Switzerland
O Czech Rep. T Turkey U Ukraine
U Russia Federation Z Macedonia Y Latvia
E Estonia L Lithuania S Slovenia
Y Yugoslavia
AUM-13
AUM-13 is a sequential 13 tone mode, which is optimized for the transmission of numeric codes. AUM-13
is similar to SP-14.
Parameter Value
Frequency range HF
Operation modes Broadcast, unprotected
Modulation MFSK-13
Symbol rate 8 Bd
Shift/Bandwidth 480 Hz
Receiver settings DATA, CW, LSB or USB
Input format(s) AF, IF
Each tone has been assigned a character:
 10 tones are assigned to the numerals 0-9
 One tone is used as an idle character
 One tone is used as a space character
 One tone is used as a repetition indicator
A transmission is initiated with a start sequence, which identifies this mode and may be used for accurate
tuning. This sequence is transmitted at 1 Baud, which makes it readable even during very unfavorable
conditions.
The data proper is transmitted at a rate of 8 Baud. As the transmission rate is very low this mode is insen-
sitive to fading and multipath propagation.
A MFSK IAS will retrieve symbol clock. In order to process both baud rates used by AUM-13, the IAS has
to be configured to a baud rate of 16 Baud. Thus at a rate of 1 baud 16 symbols per transmitted symbol,
and at 8 Baud two symbols per transmitted symbol, must be received with a certain tolerance. Even if for
instance the same character is received 16 times in succession, error correction is impossible due to the
fact that in case of repetition of numerals the numeral itself is followed by the repetition indicator.
AUTOSPEC
The standard baud rate for AUTOSPEC is 68.5 Bd.
The parity dependent repeat transmission of the 5 data bits is easily recognized by ear for certain charac-
ter combinations. The IDLE signal also has a distinctive sound.
Parameter Value
Frequency range HF
Operation modes FEC
Modulation FSK