Marconi Museum |
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visits: Sunday at 10 am
working days on reservation
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 info visits
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With the word satellite we obviously refer here to the artificial satellites, and in particular to their so called civilian applications: satellite TV, weather reporting, maps, remote sensing, reset clocks, GPS technologies (Global Positioning System: the possibility of detecting with great precision the position on earth of a machine that receives radio signals from at least three different satellites).
The idea of a worldwide telecommunication system based on satellites stems from 1945 with the feasibility study of a global system equipped with three geostationary satellites. However, telecommunication satellites appeared only at the end of the 1950s, and were first on low Earth orbit and later on geostationary orbit. The first television broadcast across the Atlantic Ocean was in 1962, while the international organization INTELSAT (International Maritime Satellite Organization) was founded in 1964.
entry Satellite artificiale in the Treccani Encyclopedia
The system of mobile telephony is based on the principle of subdividing the territory - that may be covered by more network operators - in elementary service areas, called cells, each served by a base radio station. The radio mobile terminal that allows users to connect to the network and make their calls, is made of a main terminal (the so called mobile telephone) and a microprocessor electronic module, called SIM card (subscriber identity module). When you call a user who is out of the area covered by your operator, that user is roaming with another operator.
In a mobile telecommunication network, also called cellular network, signals are irradiated by several fixed antennas located on the territory, one for each cell (here comes the name). Every antenna transmits on a different channel in order to avoid interferences.
(source: Treccani.it)
see also Cellular Telephony in the Learn & Teach section
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