Satellite Television - How does it work?

Have you ever wondered why we have satellite television? Well I have, particularly when we already have terrestrial or land based television available. They both seem very much the same; the only difference is that with satellite you get a lot more choice of channels. Of course there is cable television as well, a big competitor for both services, but I'm going to stick to satellite television in this article.

Sattelite television is very important in areas where it isn't possible to install cable and the terrestrial television reception is weak or non-existent. Both systems use radio frequency signals to transmit and they travel in straight lines. That means that for broadcast television, which is transmitted and received by land-based antenna, the natural curvature of the earth will break the signals' direct line of sight. It also means that other land based obstacles like mountains and trees are likely to interfere with the TV signal and cause some weakening and distortion.

Using satellites to broadcast the TV signals solves the problem. Orbiting more than 22,000 miles above the ground they revolve around the Earth once every 24hrs, which is the same time as it takes the planet to make one complete rotation. Therefore the satellite will always stay above the same spot on the ground and it is said to be in geostationary orbit. Because the satellite is very high in the sky the transmission of the signal reaches large numbers of customers and people that are in normally remote and inaccessible places are able to take advantage. The satellites not only transmit direct back to the ground, but they are also in communication with each other, making a huge network to distribute to the largest possible numbers of people. Because the satellite is geostationary you only need to set your TV satellite dish once, in the best position to receive a signal. You shouldn't ever have to move it again.

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:

Showing Adverts

Advertisers pay to have their promotional material shown during the transmission. They generally pay more to have their adverts shown at peak times. I don't know anyone who likes to have the advertisements distract their entertainment but it does pay for part of it.

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.

TV Licence Fee

If you are in the UK and you have equipment that is capable of receiving TV signals then the law states you must pay for a TV licence. Note that you don't have to use the equipment; you just have to possess it. The money from the licence fee goes to pay for the British Broadcasting Company or BBC and in return we don't see any advertising or encryption on any BBC channels. This was a good idea in the early days of radio and TV and it helped to produce and maintain high standards of broadcasting all over the world. My personal opinion now however is that the licence fee is nothing more than yet another tax that we have to pay and I feel that the BBC should begin to stand on it's own two feet. I doubt that it will happen anytime soon though.

If a broadcaster uses only advertising to pay for their service then you may receive and view the signals without payment or subscription. If you live in the UK you still have to pay the licence fee though.

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

The sattelite television provider receives signals from the programming sources at the 'broadcast centre' and transmits the signals out to the satellites in orbit around Earth.

Satellites

Satellites receive the signals from the centre and rebroadcast them back to the land.

Receiving equipment

The equipment normally provided by the DBS, allowing you to receive the signal from the satellite. A dish must be installed professionally somewhere on your property.

Decoding and viewing

A box close to your TV will take the received signal and decode your chosen channels so that you can watch them.

So, there is a lot more to satellite TV than meets the eye but it provides us with high quality television, which is available almost everywhere on the earth. We have come a long way in a very short time with television.

Article Source: http://www.christiannotepad.com

Steve is a software engineer and keeper of Sattelite Television www.sattelite-television.thegrandfatherclock.com