Saved Bookmarks
| 1. |
Satellite communication is a mode of communication of signal between transmitter and receiver through satellite. The satellite communication is like the line of sight microwave communication. A communication satellite isa space craft placed in an orbit around the earth provided with microwave transmitting and receiving equipment called Radio transponder. The range of microwave frequencies used in satellite communication for uplink is 5.925 GHz "to" 6.425 GHz and for downlink is 3.7 GHz "to" 4.2 GHz. (i) How is the line of sight microwave communication possible through satellite? (ii) Why can't a single satellitecover the whole earth for microwave communication? (iii) What is the practical utility of satellite communication? |
|
Answer» Solution :(i) The line of sight communication stands for the transmitter and receiver in sight of each other. The line of sight microwave communication is POSSIBLE if the communication satellite is always at a fixed locations with respect to EARTH, i.e., the satellite which is acting as a radiotransponder must be at rest with radiotranspondermust be at rest with respect to earth. it is so for a statellite KNOWN as geo-stationary satellite. (ii) A single satellite cannot cover the whole earth because, the LARGE part of the earth is out of sight due to curvature of the earth. The satellite communication is like the line of sight communications. (iii) In order to have microwave communication link over the ENTIRE globe of earth, at least three geostationary satellites are required, which are 120° apart from one another. The satellite communication is also used effectively in mobile communication especially in remote hilly areas. It is highly economical compared to other communication systems. |
|