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Satelitte HDTV
HD Satellite TV・s transmission signals are mainly
conveyed through the Earth・s communications satellites. It is
positioned either in highly-elliptical or in geostationary orbit;
that is 37,000 km up to the Earth・s equator. HD Satellite TV needs
an uplink medium (which stores the broadcast antenna) in order for
it to properly communicate with the satellite above the Earth・s
surface.
The birth of the first satellite television was initiated by the
Europeans and Americans in 1962 through Telstar satellite. In 1963,
Syncom 2 became the world・s first ever geosynchronous communication
satellite. It was on April 6, 1965 that satellite television was
introduced commercially. The Russians introduced the Orbita, the
first national network of satellite television in 1967. And the rest
is history.
At present HD Satellite TVs are following sets of international
standards. These include the MPEG and the DVB-S open standards. For
security reasons, HD Satellite TV manufacturers are using different
encryption system such as the VideoGuard, Irdeto, Conax, BISS,
Viaccess, Videocipher, Nagravision, PowerVu, and Digicipher.
HD Satellite TV・s major elements are the programming sources, the
broadcast center, the satellite, the satellite dish, and the
receiver. The programming sources are the TV channels (such as
Discovery Channel and ESPN), the broadcast center is the core of the
system (it accepts signals from the programming sources), the
satellite is the rebroadcaster of the received signals, the
satellite dish collects the satellite・s transmission, and the
receiver routes the signal to the TV.
HD Satellite TV gets their list of programs or channels from a
direct broadcast satellite (DBS) or more commonly known as
"Direct-To-Home" provider. This system applies the Ku transmission
band and C-band radio. Among the most popular DBS provider are
DirecTV, Dish Network, Primestar, and VOOM HDTV Satellite Service.
Currently, VOOM has 39 high definition channels. These include 21
latest programmings and commercial-free HD channels of sports and
movies.
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