Conclusion; Table 3-10 Scenario 2 - Optimized Carrier Coding And Bandwidth; Table 3-11 Scenario 2 - Optimized Power Requirements - ND SatCom SKYWAN IDU 7000 Manual

Using a 3.8m antenna for the Casablanca earth station we can achieve the following modula-
tion and coding parameters:
Star Network;
3.8 m Antenna
Casablanca
Modulation
FEC
Estimated Symbol
Rate [ksps]
Table 3-10 Scenario 2 - Optimized Carrier Coding and Bandwidth
Star Network; 3.8 m An-
tenna Casablanca
Home Channel
Power requirement [W]
Amplifier power class [W]
Power equivalent band-
width [kHz]
with UPC (Home Channel)
Carrier bandwidth [kHz]
(Home Channel)
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.
2010-10-26
Carrier 1
8PSK
6/7
2138
Madrid Berlin
1 1
16.7 11.6
20 20
1982 1831
2566 2566
Network Design and Engineering Guide
Outdoor Unit and Satellite Link Design
Carrier 2
8PSK
6/7
1736
Rome
2
16.3
20
1870
2083
Link Budget Examples
Total bandwidth re-
quired ( carrier spac-
ing = 1.2) [KHz]
4649
Casablanca Tunis
2 2
17.7 22.6
20 30
1501 1836
2083 2083
105