Microwave systems are used for microwave data communication, using very high frequency radio signals to transmit data through space ( Wireless Communication ). However, at microwave frequencies, as the waves cannot pass through the obstacles, like buildings or hilly areas, mountains etc. So the transmitter and the receiver of a microwave system which are mounted on very high towers, should be in the line-of-sight. This may be impossible after a very long distance transmission. After traveling a specific interval, the signals become weaker and weaker.
To overcome this problem, repeater are used at a specific interval of about 25 to 30 kilometers between the stations.
Microwave systems have speed of about 16 Giga bps. They can support about 250,000 voice channels simultaneously. As they support wireless communication, they do not require laying of cables and associated cost of land digging. However, since their initial installation cost is high, they are cost effective only for communication systems that link big cities with heavy telephone/data traffic between them.