More on how it works!
Communications satellites located in geostationary orbit about the Earth are used to send television signals directly to the homes of viewers—a form of transmission called direct broadcast satellite (DBS) television. Transmission occurs in the Ku band, located around 12 gigahertz (12 billion cycles per second) in the radio frequency spectrum. At these superhigh frequencies, radio waves tend to propagate as narrow beams, so that the receiving antenna can be a small dish only 46 cm (18 inches) in diameter. More than 100 programs are available over a single DBS service. Since competing services are not compatible, separate equipment is needed for each. Also, the receiving antenna must be carefully aimed at the appropriate satellite.
DBS transmission is digital. Normally, considerable bandwidth would be required for a digital television signal; however, by capitalizing on the redundancies inherent in a series of moving pictures, compression techniques reduce the transmission rate to 2–4 million bits per second. Decoding of the signal is performed by a set-top convertor box that is also connected to a telephone line. The telephone connection is used to send data about which shows are being watched and also to obtain permission to receive premium programs.
where is this from?
http://www.britannica.com/eb/article-235352/television
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