Satellite communication is a form of wireless media in which the free space is used for communication. One important advantage of such media is that a large geographical area can be covered without actually carrying out the physical wired networking. Such a communication with the help of satellites is possible when the signal is sent from ground stations to the satellites placed in geostationary orbits, which in turn sends the signal back to another ground station/s located in different city, country or region depending upon the placement and alignment of the satellite. The ground based infrastructure plays a crucial role in this transmission process. The earth station closely monitors the movement of the satellite and keeps sending the signals to it. The signal are received by the transponder and then sent back. A number of commercial and domestic applications are now dependant on the satellite communication. With emerging technologies, standards, and protocols the usage of satellite communication in transmission, broadcasting and internet is also becoming cost effective.
During this training I learned about the fundamentals of ground segment and earth station and how the satellite communication has evolved over the years from being a commercial facility with huge dish 30 m diameter antennas to small sized rooftop 0.6 m dish antenna for receiving DTH broadcasts. This has effectively made it possible even for the ordinary consumers to make use of satellite communication.
In fact the range of advantages that satellite communication could bring in includes;
Provisioning of multi-access two way communication between any two points on the earth.
The cost of transmission is not dependent on the distance covered. The cost in turn depends upon the time period during which the communication takes place.
Satellites are capable of handling very large bandwidth, thus a large number of consumers can be benefitted from the use of a single satellite.
Satellites can provide communication and broadcast coverage even to places like valleys, dense forests, mountains and difficult terrains where it is not possible to erect communication towers or dig channels for communication lines. All this can be provided at practically no extra costs. What we require is a receiving dish antenna with other gadgets used at other similar places.
Satellites can provided uniform signals without any discrimination for urban or rural areas unlike the terrestrial transmission networks where the emphasis happens to be more towards coverage of urban population.
With the emergence of smaller satellite uplink gadgets like SNG and DSNG setting up of an uplink and downlink earth station has become quite handy. In fact, the DSNG (Digital Satellite News Gathering) equipment has become an integral part of the broadcasting set up all over the world.
The basic components of a satellite communication system include;
i. Ground Segment
ii. Space Segment
The Ground Segment: The ground segment or earth station is responsible for receiving the communication and broadcast signals from the satellite and then passing them on to the consumers using cables or terrestrial transmission system. These earth stations can be distinguished by the size of the earth station which varies according to the volume of the communication or broadcast traffic. Some of these earth station