What is an Uplink?
• The communication between the
earth channel transmitter and the
satellite is called the uplink.
• The satellite uplink is usually where
the earth channel transmits signals
and satellite receives it.
• The uplink frequency ranges from 5.9
GHz to 6.4 GHz.
• The conventional Ku-band that is used
for the satellite communication in
Europe has the uplink frequency
range of 14.0 to 14.5 GHz.
• In the case of a radio-communication
service, an uplink is used to transmit
signals from a global station to a radio
station or a high-altitude platform.
• For global service module (GSM) and
mobile networks, radio radiated
uplink is a method of transferring
from a portable station (mobile
phone) to a base station (mobile
domain).
optical to electrical to
uplink uplink
electrical optical
transmitter receiver
conversion conversion
blue opt.ical G
filter with PD
Uplink segment
What are Uplink and Downlink
in satellite communication?
Satellite links are used to provide
connections between very large distances
also called the global broadcasting. This is
achieved by using a satellite as a repeater.
The channel below transmits the signal
upwards that is towards the satellite with a
frequency known as the uplink frequency.
The satellite receives this signal and it also
broadcasts it with a downlink frequency to
another sub-channel. If a digital
communication signal is used, the signal
may be regenerated before it is transmitted
back to earth.
Return link
- ~~
~
0~
Q
0~-~
~"·d-0
t ~-
~
~~ ~-
~-f
~~-
~.f
Forward link
Satellite communication
The satellite receives a radio signal from its
uplink receiver. Then sends this signals to
the group with downlink frequency, the
signal is amplifier before sending back to
the ground that is to the transmission
antenna. These operations are performed
via satellite transponder.
At present, there are four main antennas
used in communication satellites:
telephone antennas, horn antennas, optical
reflectors antennas and many more.
The satellite communication system can be
further divided into 2 parts:
Space segment
The space segment includes satellites and
low-level resources like telemetry tracking
and commands. The space segment of the
synthetic satellite system is one of its three
functional components the other two
includes the transmitter on the ground and
the user. The communications satellite is
built with a paid communications loader
(repeater and antenna) and a supportive
spacecraft bus (including solar array and
batteries, attitude and Orbital systems,
building and temperature control system),
and is orbital by the launch vehicle.
Earth segment
The earth segment includes the transmitter
and the commanding unit. The transmitting
unit consists of the transmitter to send the
signal to the satellite using uplink. Various
companies can rent the ground segment
instead of building their own, like in case of
the television industry. The earth segment
also include commanding unit that include
that is used govern the operation of the
satellite on the earth. A satellite can be
assigned a particular Earth segment so that
the satellite follows it only throughout 24
hours.
Common Mistakes
Uplink and downlink splitting in high-load
wireless communication systems depends
on the service provider and the number of
users with high traffic density.
Context and Applications
In each of the expert exams for
undergraduate and graduate publications,
this topic is huge and is mainly used for:
• Bachelor of technology in the
Electrical and Electronic department
• Bachelor of Science in Physics
• Master of Science in Physics
