Satellite-Television---How-does-it-work-
Ever wondered why we have satellite television? I know I have, particularly when we already have terrestrial or broadcast television available. They both seem very similar, the only difference being that with satellite you get lots more choice of channel. Of course there is cable television too, a fierce competitor for both services, but in this article I am going to stick to satellite television.
The local terrain and the curvature of the earth limit terrestrial TV signals in the area that they can server. Both terrestrial and Satellite TV use essentially the same kind of signals but by beaming the signal from above, one satellite is able to serve a wider area. This is why satellite television has become popular in remote areas where it isn't practical to serve people with a land based antenna and certainly not economic to provide cables to those areas.
Satellites that transmit TV are placed in orbit over 22,000 miles above the Earth and they rotate around the planet once every 24 hours and in the same direction that the Earth is rotating in. Because the Earth rotates once every 24 hours and the satellite moves around the Earth at the same velocity in the same direction, the satellite always stays over the same point on the surface. The satellites are said to be in geostationary orbit. Because they are high in the sky a satellite beams signals over a wide area of the planets surface. The satellites are also in communication with each other so that they can relay the same broadcast to all satellites in orbit over different parts of the world. This is how we are able to get TV live from anywhere on the Earth and view it at the same time as everyone else on the planet receiving a signal from a satellite. When you think about it it's a pretty amazing feat of technology.
It is possible to set up a satellite dish on you property and receive signals from a number of different satellites, often for free. To do this you will need a dish that can be moved to point at the satellite you want to receive signals from. Some satellites of interest to amateurs aren't even geostationary so you can only get signals from them for part of the day and your dish needs to be able to track the satellite as it moves across the sky. Most people however want to receive signals for entertainment with the least amount of fuss and so they subscribe to paid 'Direct Broadcast Satellite' (DBS) services like DirecTV, Dish or Sky (UK). The premium channels streamed from these satellite networks are encrypted so you need special equipment to view them and you pay for the encryption key to unlock the decoder.
To enable the whole system to make money for the organisations involved in the provision of satellite television, three techniques are commonly employed:
Advertising
Organisations pay the network to broadcast adverts. We all hate it but it does pay for our entertainment, or part of it at least.
Regular Subscriptions
Payment of a monthly fee for the privilege of being able to view encrypted channels. For your subscription you generally get a smart card that is loaded with the decryption keys and inserted into your receiver equipment.
Licence Fee
If you live in the UK and you possess equipment capable of receiving TV signals then by law you have to pay a licence fee. Note that you don't have to ever use the equipment to receive and view TV; you just have to possess it. The revenue from the licence fee pays for the British Broadcasting Company or BBC and in return we don't expect to see advertising or encryption on any BBC channels. This was a good idea in the early days of broadcasting and helped to produce high standards all over the world. My personal opinion however is that now the licence fee serves no purpose other than yet another tax we have to pay and I feel that the BBC should now stand on it's own two feet. I doubt if that's going to happen anytime soon though.
If a broadcaster only uses advertising to support their service then you may receive and view the signals without further payment or subscription. If you are in the UK though you still have to pay for a licence.
There are five components needed to link the programme makers and the satellite television customer:
Distribution
The DBS provider does not create the programmes themselves, they pay for the right to be able to broadcast them via satellite television. They act as a 'middleman' between the 'programming sources' or channels and you.
Satellite Television Provider
Signals from the broadcast sources are received by the provider and then transmitted to the network of orbiting satellites.
Satellites
The signals are received by the satellite network and retransmitted back to Earth.
Receiving equipment
Usually a DBS provider will provide you with the equipment to receive the signal. This will include a dish to be fixed to your house by professional installers to receive the signal.
Decoding and viewing
That signal is then transferred to and decoded by the receiver, which is usually sited next to your television so that you can view the channels you have chosen to purchase.
I bet you never realised that there was so much involved in satellite television. It is indeed a marvel of technology and provides us with high quality up to date entertainment from all over the world. Television technology has come a very long way in such a short time.
Content Provider: http://www.my-articles.com
More About Steve Gee: Steve is a software engineer and keeper of Sattelite Television www.sattelite-television.thegrandfatherclock.com
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