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VSAT:
VSAT is an acronym for Very Small Aperture Terminal, and generally refers to a satellite dish of 3.8m
or less located at the remote location. Satellite communication is used for internet connection in remote areas of the
world where a connection to the traditional copper or fibre network is not possible.
It is also used as a backup communication link for mission critical systems such as remote autonomous mine sites
and offshore Oil and Gas rigs.
VSAT links are used for both internet data and voice (VoIP – Voice over IP) traffic.
There are many different types and sizes of satellite dish and equipment to choice depending on the frequency band,
satellite orbit, bandwidth, network topology, etc. Internet speed can vary between
128kbps or up to 72Mbps and above for luxury cruise liners!
How fast the link depends on your budget!
Positioned one-tenth of the way to the moon (about 36,000 km) are Geostationary (GEO) communication satellites.
Many satellite service providers use Geo stationary satellites as they appear to be stationary viewed from Earth
and therefore can use a fixed dish.
However, tracking antennas can also be used in VSAT for MEO satellite like the O3B network or for satellites in inclined orbit.
See What is VSAT:
VSAT TOPOLOGY
ORBITS
FREQ BANDS:
Satellite VSAT communication is split up in to four Radio Frequency (RF) bands that commercial communication and military satellites operate within.
These different frequency bands have separate uplink (Tx) and downlink (Rx) frequencies,
require different RF components (LNB and BUC) and are suited to different applications.
C Band
uplink 5.925-6.425 GHz downlink 3.7-4.2 GHz The C band is primarily used for voice and data communications as well as backhauling.
Because of its weaker power it requires a larger antenna, usually above 1.8m (6ft).
However, due to the lower frequency range, it performs better under adverse weather conditions on the ground.
C Band is part of the 5G multi-bands spectrum.
X Band
uplink 7.9- 8.4 GHz downlink 7.25 – 7.75 GHz The X band is used mainly for military communications and Wideband Global SATCOM (WGS) systems.
With relatively few satellites in orbit in this band, there is a wider separation between adjacent satellites, making it ideal for Comms-on-the Move (COTM) applications.
This band is less susceptible to rain fade than the Ku Band due to the lower frequency range, resulting in a higher performance level under adverse weather conditions.
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