DEFINITION:

Satellite telecommunication is the most mature of space applications. Starting 50 years ago with the launch of Telstar in 1962 and Syncom in 1963, satcom has continued to grow ever since.

At first, satellite performance was very limited. To compensate for this, very large ground stations with dish antennas more than 20 metres in diameter were required to establish links with them. The use of satellites was limited to long distance telephony and to the transport of television signals between studios.

New technology and different kinds of demand have changed the way communications satellites are used. More powerful satellites and the use of higher frequencies have made it possible for many people to receive direct signals from the sky. At the beginning of the 21st century, more than 100 million European homes were able to watch television programmes transmitted by satellites, either by direct reception or through cable distribution systems.

• When you listen to the radio, it is very likely that the signal you are receiving has been distributed from the central studios by satellite.
• Many newspapers and magazines are produced locally but printed centrally: the content of the paper is sent to the printing plants using satellite links.
• Even when a news or sports event shown on television is taking place just a few kilometers away from the studios, it has probably been transmitted via satellite.
• Most news agencies use satellites to distribute text, audio and video to their affiliates.
• In many countries, access to the Internet is by satellite communication and with the emergence of very powerful broadband satellites, users – equipped with their own broadband interactive satellite terminals – will get access to the Internet regardless of their distance from the nearest terrestrial node.
• Big satellite constellations al MEO orbits are currently under development to provide universal Internet and communication service all around the world.

(Source: PAE own elaboration from ESA’s web page:

http://www.esa.int/Our_Activities/Telecommunications_Integrated_Applications/Telecommunications_satellites )