Output Back-Off; Figure 3-15 Link Budget Tool - Define Network - ND SatCom SKYWAN IDU 7000 Manual

Step (3) For each network up to 20 earth station parameter sets may be defined:
- "Location": Each earth station is identified by a unique location name. The first
column is reserved for one master station, because the home channel of this sta-
tion is fixed to carrier 1. For star networks, the first two columns represent the net-
work's hub stations, the remaining stations are considered the remote terminals
of the network.
Figure 3-15 Link Budget Tool - Define Network
- ITU-T 'Rain Zone'.
- 'Longitude' and'"Lattitude': Geographical coordinates (positive values means
northern/eastern hemisphere).
- 'Uplink/Downlink Pattern disadvantage': To be taken from the satellite footprint di-
agram. Stations in the beam center have a disadvantage of 0 dB, for other sta-
tions the difference between maximum and actual G/T or EIRP has to be entered.
- 'Antenna': type according to the defined frequency band of the network the pull-
down menu allows the selection of any antenna type defined in the Ku- or C-Band
antenna sheet before.
- 'Output Backoff': The difference between saturation power and maximum usable
output power of the station's amplifier.
- 'Number of IDUs at location': the number of IDUs which are connected to the sta-
tion's ODU.
- 'Altitude' of geographical station position.
- 'SkyWAN
ry demodulator.

Output Back-Off

The output back-off is needed to prevent intermodulation created by operating the amplifier too
close to the saturation level. The necessary back-off is higher when more than one carrier is
transmitted at the same time. In the case of SkyWAN
IDUs are connected to the same amplifier. In this case recommended values for output back-
2010-10-26
®
Receive Home Channel': The carrier used for reception on the prima-
Network Design and Engineering Guide
Outdoor Unit and Satellite Link Design
®
SkyWAN Link Budget Calculation Tool
®
stations this is only possible if multiple
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