10
6. Operating the Antenna
After the cable connections are made, apply power (10-32V DC) to the Power Supply,
AS03951 and switch it on.
Wait for the SpaceCom IP221 Landmobile Antenna to acquire the satellite signal, this
takes approx. 1 minute.
Switch the Thuraya IP terminal on when the antenna is ready (see Section 6.1). Let the
terminal acquire the satellite network as described in the Thuraya IP manual.
6.1
Satellite Acquisition
The tracking antenna performs a full hemispherical satellite search to acquire the Thuraya
satellite every time power is applied. This takes approx. 1 minute.
6.1.1 Blocking of the Satellite
If blocking of the satellite signal happens, the antenna controller detects loss of the signal
from the satellite (can occur if large objects block the line-of-sight to the satellite).
The antenna controller will first try to reacquire the satellite by turning around two times
which usually will take only a few seconds. If this fails a full hemispherical acquisition is
performed to reacquire the satellite which can take up to 1 minute if a satellite signal is
available. If no signal is available the antenna will continue to scan the sky until a signal
can be acquired.
The antenna controller can stabilize the antenna at signal levels that are lower than the
operational limits of the Thuraya terminal.
6.2 Satellite choice
The Thuraya satellite system consists of 2 satellites with each satellite having its own
beacon the antenna can track. In order for the Thuraya IP terminal to have connection to
the network, the antenna must track the correct satellite.
When the antenna performs a satellite search it will search for both satellites but in most
covering areas only one satellite is visible and the antenna automatically detects this and
tracks the visible satellite.
In certain areas both satellites are visible and therefore the antenna can track either of
them, but only one of them will allow the Thuraya IP to connect to the network. The area
with both satellites visible is from longitude 60° East to 110° East.
In the case where the antenna tracks the wrong satellite no service will be available.
The user can redirect the antenna to the other satellite by, within the first 15 minutes after
powering on the system, toggling the power switch on the antenna power supply,
AS03951. This will redirect the antenna to track the beacon of the other satellite visible. It
is not necessary to power off the Thuraya IP terminal.
