Wireless communications networks are networks that require unguided media (like radio, infrared and microwaves).
Satellites are man-made systems that operate in space, orbiting the
earth.
These are microwave transmission systems in space.
They act as amplifiers and repeaters - receive data signals,
amplify and retransmit them.
Satellites have a number of transponders each of which covers a designated band of frequencies,
and are used for receiving and transmitting signals.
Satellites are specifically made for telecommunication purpose. They
are used for mobile applications such as communication to ships,
vehicles, planes, hand-held terminals and for TV and radio
broadcasting.
They are responsible for providing these services to an assigned region (area) on the earth.
The power and bandwidth of these satellites depend upon the preferred
size of the footprint, complexity of traffic, cost of ground stations.