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Satellite Television - How does it work?

By: Steve Gee 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.

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.

When satellite television was first available the dishes needed to receive the signal were very expensive and people would set them up to receive programmes that were not really intended for everyone's eyes. Nowadays people typically subscribe to a 'Direct Broadcast Satellite' (DBS) provider such as Dish Network or DirecTV in the US and Sky in the UK. These providers are able to select channels and broadcast them to people in the form of packages, for example the 'Family', 'Movie' or 'Sports' packages. The price depends on which packages you choose to subscribe to.

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 for their advertising material to be shown during the transmission. They often pay more to have their adverts transmitted at peak times. I don't know of anyone who likes to watch adverts and have them distract our entertainment but it does pay for some 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 main components required to make this whole system work. To get the programmes from the producers to the end customer they must all be in place and they must all be working properly. It's surprising how it works at all.

Distribution

The DBS provider distributes programmes but they don't create them. They are in the middle between the consumer and the programme sources.

Satellite Television Provider

Signals from the broadcast sources are received by the provider and then transmitted to the network of orbiting satellites.

Satellites

The satellite network receives the signals, which are then retransmitted back to Earth.

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

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.