ND SatCom SKYWAN IDU 7000, Manual

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2010-10-26 Network Design and Engineering Guide 105
Outdoor Unit and Satellite Link Design
Link Budget Examples
Using a 3.8m antenna for the Casablanca earth station we can achieve the following modula-
tion and coding parameters:
Table 3-10 Scenario 2 - Optimized Carrier Coding and Bandwidth
Table 3-11 Scenario 2 - Optimized Power Requirements
Conclusion
Compared to the situation with a 2.4 m antenna in Casablanca the following parameters have
changed:
-
ODU hardware cost is higher because of using a bigger antenna in Casablanca.
- Amplifier cost is unchanged because the 30 W amplifier is now used in Tunis instead of
Casablanca.
- Due to higher FEC coding on both carriers the transponder bandwidth for the network is
again reduced by 1200 kHz.
- Power and bandwidth usage on the transponder is now equilibrated for both carriers.
The bandwidth saving should again compensate the higher antenna and installation cost in
Casablanca within a short time provided that the site in Casablanca allows the installation of a
3.8 m antenna.
Further carrier optimization is not possible, because we have reached on both carriers maxi-
mum modulation and FEC. Putting bigger antennas on other sites than Casablanca would re-
duce power classes on the earth stations, but probably not the overall ODU cost for the
network.
Star Network;
3.8 m Antenna
Casablanca Carrier 1 Carrier 2 Total bandwidth re-
quired ( carrier spac-
ing = 1.2) [KHz]
Modulation 8PSK 8PSK
FEC 6/7 6/7 4649
Estimated Symbol
Rate [ksps] 2138 1736
Star Network; 3.8 m An-
tenna Casablanca Madrid Berlin Rome Casablanca Tunis
Home Channel 1 1 2 2 2
Power requirement [W] 16.7 11.6 16.3 17.7 22.6
Amplifier power class [W] 20 20 20 20 30
Power equivalent band-
width [kHz]
with UPC (Home Channel) 1982 1831 1870 1501 1836
Carrier bandwidth [kHz]
(Home Channel) 2566 2566 2083 2083 2083