ND SatCom SKYWAN IDU 7000, Руководство пользователя

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2010-10-26 Network Design and Engineering Guide 75
Outdoor Unit and Satellite Link Design
Satellite Beam Footprints
The white contour lines represent areas with a specific signal intensity expressed in terms of
Equivalent Isotropic Radiated Power [dBW]. The yellow contour lines specify the earth station
elevation angle [°].
Figure 3-3 SES World Skies NSS-7 Satellite Spot Beam Footprint
Satellite Choice Considerations
Let’s assume that we have to design a network with stations in South America and Africa. The
NSS-7 global beam would cover the entire area. If the stations would be located in Europe and
Africa, the east hemisphere beam would be more suitable, because the beam intensity is typ-
ically 5 dB higher compared to the global beam.
Finally let’s consider a network with stations in Brazil and Angola. Both areas are served by a
high power Ku-Band spot beam. If cross-strapping between these beams is supported on the
satellite, a single
Sky WAN
®
network operating in MRB-DUB or NFB-DUB mode may use this
spot beams. Compared to a network running on the global beam the power advantage would
be typically 14 dB, allowing a substantial reduction of the earth station’s ODU equipment.