How Satellite TV Works – A Simple Explanation
Satellite tv is talked about so much in the world of consumer viewing. Satellite dishes, receivers, program packages, PVRs, DVRs, HDTV – what does it all mean? How can you even begin to think of buying a satellite tv system when you’re bombarded with all these meaningless terms? So suppose you really knew exactly how satellite tv works? Wouldn’t that put you in a more positive position? Wouldn’t that allow you to make an informed decision when shopping for a satellite tv system?
There are many pages on the Internet explaining how satellite tv works. Many have a lot of technical information. We’d like to take a simpler approach. So, the following is an explanation of just how satellite tv works – in layman’s terms. Take note – and you can secure some useful knowledge.
Satellite tv is a wireless system for delivering tv programming directly to a viewer’s house. It transmits its broadcasts via a radio signal.
The ultimate source of this radio signal is the broadcast stations. They use a powerful antenna to transmit their broadcasts to the viewers. However, these radio signals can travel only in straight lines. So the signal can’t be captured by the viewer on his receiver unless he is in the line of sight of the broadcaster’s signal. Tall buildings, trees, and other such obstructions, can’t block the signal, but it could be blocked by the curvature of the Earth. Therefore, broadcasters needed another medium to transmit their signals to the viewers. Enter satellites.
Satellites were launched. They orbited the Earth at exactly the same speed as the Earth (7,000 mph or 11,000 kph), at a distance of 22,200 miles (35,700 km), thereby creating a geosynchronous orbit, that is, they appeared to be “stationary” above the Earth, “hovering” over a certain point. The result of this geosynchronous orbit is that signals (broadcasts) could be directed from the Earth to the satellites and continually engage them in receiver transmissions.
So now on the ground there was a need for an antenna to receive these broadcasters’ signals. Enter satellite tv systems. These very large satellite dishes started popping up in people’s back yards. Although the satellites took up large areas of the viewer’s property, the programming was very rewarding. The owners of these big satellite dishes could pick up foreign stations, live feeds between broadcast stations, NASA activities and a lot of other programs transmitted using satellites.
Progress brings smaller and more efficient technology
Then direct broadcast satellite (DBS) providers decided to collect the programs available via satellite and re-sell them to the viewer. But the broadcasters (for example, HBO and ESPN) weren’t about to just give away their programs. They charged the DBS providers a fee for these rights. So in essence, the DBS providers are like brokers – they buy programs wholesale and re-sell them for a profit. Two of the most well-known DBS providers are DIRECTV and the Dish Network.
The next challenge for the DBS providers was to create a system more cost-effective and simpler than the large satellite dishes. So they came up with a small satellite dish that viewers could easily attach to their houses or apartments. This opened up a whole new market for their programs.
Program packages were created by selecting certain channels and bundling them, often in a theme – like sports, movies, documentaries, retro, etc. Viewers could choose the package that best fit their viewing preferences, and wouldn’t have to pay for channels they weren’t interested in.
So in review, here’s the basic path of a radio signal containing television programming: the programming source (the broadcaster), to a satellite, to the DBS broadcast center, back to a satellite, to the viewer’s receiver, to the television set.
Exactly how is this signal sent?
Early satellite tv was broadcast in C-band radio (3.4 GigaHertz [GHz] to 7 GHz). Remember, the picture and sound making up the signal is actually a radio signal. But the broadcasters wanted to provide superior video and audio to its viewers, so they started transmitting their programs in the Ku frequency (12 GHz to 14 GHz). Thus was invented High-Definition Television (HDTV). Now the picture and sound were theatre-like in quality. This also gave them a jump on their competition – the cable companies.
Now for a quick, but not too deep, look at the technology of the satellite signal. The original broadcasts are converted into a high-quality, uncompressed digital stream containing a lot of data, and sends it at a speed of 270 megabits per second (Mbps) for each channel. But unless all this data was compressed, the satellite wouldn’t be able to accept it.
The system of compression used in the U.S. is the MPEG-2 compressed video format. This is similar to the system used to make DVDs. The provider could now reduce the 270-Mbps stream to about 5 or 10 Mbps, enabling them to transmit about 200 channels, instead of the 30 they could transmit before compression. The signal was scrambled so only paid subscribers could receive it.
This was the turning point towards the huge success the DBS providers now experience. Again, this put them ahead of the cable companies.
The Receiver – the end and the beginning
The receiver is almost at the end of the signal’s journey, accepting the program signal and converting it into a format that can be viewed on your tv. It’s also the beginning of your viewing pleasure. The receiver does three basic things:
Receivers do a few more jobs as well. They display a “TV Guide” (your onscreen programming guide), which comes as part of the signal from the satellite. You can also get special receivers, called Digital Video Recorders (DVRs), which let you pause or record live television.
So now we’ve traced the radio signal from its inception at the broadcaster to its reception on your television. And now you know just how satellite tv works. You’re qualified to make an informed decision when buying a satellite tv system.
About The Author
Gareth Marples is a successful freelance writer providing tips and advice for consumers purchasing satellite tv dishes, reseller hosting and Verizon DSL company. His numerous articles offer moneysaving tips and valuable insight on typically confusing topics.
This article on "How Satellite TV Works" reprinted with permission.
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