Satellite TV

Satellite TV



he ComponentsThere are five major components involved in a direct to home (DTH) or direct broadcasting (DBS) satellite system: the programming source, the broadcast center, the satellite, the satellite dish and the receiver.

Programming sources are simply the channels that provide programming for broadcast. The provider doesn't create original programming itself; it pays other companies (HBO, for example, or ESPN) for the right to broadcast their content via satellite. In this way, the provider is kind of like a broker between you and the actual programming sources. (Cable TV companies work on the same principle.)

The broadcast center is the central hub of the system. At the broadcast center, the TV provider receives signals from various programming sources and beams a broadcast signal to satellites in geosynchronous orbit.

The satellites receive the signals from the broadcast station and rebroadcast them to Earth.

The viewer's dish picks up the signal from the satellite (or multiple satellites in the same part of the sky) and passes it on to the receiver in the viewer's house.

The receiver processes the signal and passes it on to a standard TV.

Satellite TV Programming

Satellite TV providers get programming from two major sources: national turnaround channels (such as HBO, ESPN and CNN) and various local channels (the ABC, CBS, Fox, NBC and PBS affiliates in a particular area). Most of the turnaround channels also provide programming for cable TV, and the local channels typically broadcast their programming over the airwaves.

Turnaround channels usually have a distribution center that beams their programming to a geosynchronous satellite. The broadcast center uses large satellite dishes to pick up these analog and digital signals from several sources.

Most local stations don't transmit their programming to satellites, so the provider has to get it another way. If the provider includes local programming in a particular area, it will have a small local facility consisting of a few racks of communications equipment. The equipment receives local signals directly from the broadcaster through fiber-optic cable or an antenna and then transmits them to the central broadcast center.

The broadcast center converts all of this programming into a high-quality, uncompressed digital stream. At this point, the stream contains a vast quantity of data -- about 270 megabits per second (Mbps) for each channel. In order to transmit the signal from there, the broadcast center has to compress it. Otherwise, it would be too big for the satellite to handle. In the next section, we'll find out how the signal is compressed.

Cable: Satellite's Biggest Contender

With emerging technologies in each service, the hardest decision in TV viewing is no longer just what channel to watch -- it's what service to choose.

Cable advantages: Advancements in digital cable provide improved audio and picture quality with additional channels at a lower cost than satellite. You can also access cable channels from multiple rooms in your house fairly easily.

Cable disadvantages: Cable has limited access in rural areas, and you should prepare for increased service costs as your provider updates its ...