Two stations on earth want to communicate through radio broadcast when they are too far from each other to communicate by any conventional method suggest a method that how these two stations can communicate with each other
Answers
A satellite is an object that revolves around another object. For example, earth is a satellite of The Sun, and moon is a satellite of earth.
A communication satellite is a microwave repeater station in a space that is used for telecommunication, radio and television signals. A communication satellite processes the data coming from one earth station and it converts the data into another form and send it to the second earth station.
How a Satellite Works
Two stations on earth want to communicate through radio broadcast but are too far away to use conventional means. The two stations can use a relay station for their communication. One earth station transmits the signal to the satellite.
Uplink frequency is the frequency at which ground station is communicating with satellite. The satellite transponder converts the signal and sends it down to the second earth station, and this is called Downlink frequency. The second earth station also communicates with the first one in the same way.
Advantages of Satellite
The advantages of Satellite Communications are as follows −
The Coverage area is very high than that of terrestrial systems.
The transmission cost is independent of the coverage area.
Higher bandwidths are possible.
Disadvantages of Satellite
The disadvantages of Satellite Communications are as follows −
Launching satellites into orbits is a costly process.
The bandwidths are gradually used up.
High propagation delay for satellite systems than the conventional terrestrial systems.
Satellite Communication Basics
The process of satellite communication begins at an earth station. Here an installation is designed to transmit and receive signals from a satellite in orbit around the earth. Earth stations send information to satellites in the form of high powered, high frequency (GHz range) signals.
The satellites receive and retransmit the signals back to earth where they are received by other earth stations in the coverage area of the satellite. Satellite's footprint is the area which receives a signal of useful strength from the satellite.
The transmission system from the earth station to the satellite through a channel is called the uplink. The system from the satellite to the earth station through the channel is called the downlink.
Satellite Frequency Bands
The satellite frequency bands which are commonly used for communication are the Cband, Ku-band, and Ka-band. C-band and Ku-band are the commonly used frequency spectrums by today's satellites.
It is important to note that there is an inverse relationship between frequency and wavelength i.e. when frequency increases, wavelength decreases this helps to understand the relationship between antenna diameter and transmission frequency. Larger antennas (satellite dishes) are necessary to gather the signal with increasing wavelength.