P300H P300 Series Modem Installation and Operating Handbook Page 121
Each option is as follows:
BUFFER % The buffer fill state is logged every period this allows fill trends to be monitored
Eb/No The average AND wors t case Eb/No for the period are logged at the end of the
period.
USER BER The average AND worst case estimated U S E R B ER are logged at the end of the
period.
BERT BER The BER as measured by the internal BER Tester (BE RT). This can be meas ured
either in the main data channel or when running in parallel with the main data in
either the ESC or the Aux channels. The average AND 1 second worst case
BER measured by the BERT are logged at the end of the period.
TX TERR BER T his is the BER measured at the terrestrial input. This is only available if the
terrestrial signal can be monitored for BER (ie it's framed and/or has a CRC). The
actual method of measuring it is determined by Change, User-Opt, Operation,
Terrestrial, Tx/Drop BER.
RX TERR BER As above. This is only meaningful (ie different to the Tx/Drop BER above) if the
modem is used with separate Drop/Insert bearers by the use of a twin G.703
terrestrial interface. The method of BER measurement can be selected by
Change, User-Opt, Operation, Terrestrial, Rx/Insert BER.
AUPC
DELTA POWER This logs the power variation (delta power) the AUPC has used to maintain the
target Eb/No. See AUPC in section 8. 11.1 on page 154 for further details. This is
useful in case the satellite operator requires you to determine the Tx power that
was active at any time whilst AUPC was a ctive.
DISTANT END
EB/NO This is the distant end Eb/No, available when AUPC is active (again see AUPC
in section 8.11.1 on page 154 for further details). As with the local Eb/No the
average AND worst case Eb/No for the period are logged at the end of the
period.
The automatic logging of local/distant Eb/No and various BER's, coupled with a `centralised log
accumul ation` by a M&C package (eg Alphawave `CAM`) provides a very convenient way to be able to
monitor the perform ance of any link (and have recorded data verifying the performance should anyone
query if there was a `fade`).
Please note that each data type logged uses up one log entry every Autolog period (ie the log capacity can
be consumed quickly with multiple events logged at very regular intervals).