What is a satellite? A Satellite is an object that orbits another object. There are many kind of satellites used for many purposes. For communication and entertainment artificial communication satellites are used. The orbits that are in use for satellites are geosynchronous orbits, low Earth orbits, and Molniya orbits.

What is comsat?
It is an artificial communication satellite. When compared to the other two orbits the geosynchronous orbits are best suited as it can hold a ground-based antenna, which face the satellites. For television ground antenna are essential. Arthur Clarke first founded this method in 1929.

There are different satellite reception modes. To name a few there are Direct broadcast satellite and Television receive only satellite. Direct to home or direct broadcast satellite or mini dish system, is a recent development in the world of communication satellite. The direct broadcast satellite is a completely closed system and it uses proprietary reception equipment. Direct broadcast satellite uses the Ku band and sometimes it can run in C-band satellites. For the functioning of direct broadcast satellite system, encryption based on proprietary reception equipment and proprietary transport stream encoding is required. Direct broadcast satellite uses a smart card as part of the decryption system, which keeps a check on the authorization of subscribers.

Television receive-only, or TVRO, is open standard equipment and referred to as big dish satellite. Television receive-only is a well designed to receive for both television and radio as analog and digital satellite. Television receive-only uses both C-band and Ku-band transponders on the same level. Television receive-only or big dish satellite, as the name suggests uses larger satellite dish antennas. Additional receiver boxes are also used for receiving different types of digital satellite signal reception.

The digital revolution from space is altering the way that we receive information. The more advanced form of digital broadcast system is set-top box. Set-top box is a device, which receives signals, decode digital broadcast, and makes the television user interface friendly to the Internet. Its one of the main feature is to enable analog television to receive digital broadcasts.

Overall, there is a large improvement in the evolution of television relay system. That is from broadcasting through cable to broadcasting via satellites. There was again an evolution in the satellite system itself. For broad casting via satellite system, large dish were in use. Then came the mini dish to receive signal. The mini dish is sophisticated and easy to use system where tuning and maintenance was lot more easy than the traditional dish.