Copyright © 2006 – STM Norway AS
Publication no. 101557, Rev. T, November 3
th
, 2006
Page 106
Appendix N. Standardisation of timing compensation
SatLabs did in May 2005 specify the procedure a DVB-RCS terminal shall use to compensate for the
delay from and to the sat internal delay in the terminal in order to make sure that the logon burst
sent by the terminal is received at the DVB-RCS Gateway with correct timing.
The STM SatLink terminal can be configured to be compliant with the SatLabs procedure for timing
compensation, as well as being configured to comply with any proprietary timing compensation scheme.
When delivered from the factory, the STM SatLink terminal is configured to use the STM proprietary
timing compensation procedure (slightly offset from the SatLabs procedure) used in SW versions up to
and including Release 9.1.
To show what timing compensation method the terminal is configured to use, enter the CLI command
dvb pos show.
Example:
# dvb pos show
Latitude : 59d 52.15'N ( 59d 52' 9''N )
Longitude : 10d 29.05'E ( 10d 29' 3''E )
Altitude : 60 m
Timing Reference : STM
#
To configure SatLabs compliant timing compensation, enter the CLI command
dvb pos delayburst
satlabs
.
Example:
# dvb pos delayburst satlabs
# dvb pos show
Latitude : 59d 52.15'N ( 59d 52' 9''N )
Longitude : 10d 29.05'E ( 10d 29' 3''E )
Altitude : 60 m
Timing Reference : SatLabs
#
The STM SatLink Terminal can also be configured to offset the timing of the logon burst a given number
of NCR ticks from the SatLabs timing reference by entering the CLI command
dvb pos delayburst
<ticks>
where
<ticks>
is the integer number of NCR ticks the logon burst will be delayed or
advanced compared to the SatLabs timing reference. The example below shows how to configure the
STM SatLink terminal to delay the logon burst 30000 NCR ticks (100 us) compared to the SatLabs
timing reference.
Example:
# dvb pos delayburst 30000
# dvb pos show
Latitude : 59d 52.15'N ( 59d 52' 9''N )
Longitude : 10d 29.05'E ( 10d 29' 3''E )
Altitude : 60 m
Timing Reference : Offset 30000 NCR ticks
#
