Satellite communication is an electronic communication package placed in an orbit. Its prime objective is to initiate or assist through space. It has made a major contribution to the pattern of international communication. The satellite microwave is basically a microwave relay station in space. It uses a geosynchronous satellite to relay the radio signal transmitted from the ground station. For communication signals, these satellites act as relay stations. From the earth station, the satellite accepts data/signals, amplifies them, and re-transmit them to another earth station. Data can be transmitted to the other side of the earth using such a setup in only one step. Most companies that use satellite microwave lease access to the satellites for an exorbitant fee. Satellite communication has a number of advantages:
Advantages :
- Through satellite transmission, coverage over geographical area is quite large mainly for sparsely populated areas.
- High bandwidth and broadcast possibilities .
- Wireless and mobile communication applications can be easily established by satellite communication independent of location.
- It is used in wide variety of applications such as global mobile communication, private business networks, Long distance telephone transmission, weather forecasting, radio/TV signal broadcasting, gathering intelligence in military, navigation of ships and air crafts, connecting remote areas, television distribution etc.
- Security in satellite transmission is usually provided by the coding and decoding equipment.
- Service from one single provider is easy to obtain and uniform service is available.
- Over long distances, it can be cheaper.
- The laying and maintenance is easy and cheap in satellite communication therefore it is best alternative.
- During critical condition, each Earth Station may be removed relatively quickly from a location and reinstalled somewhere else.
- Ground station sites are easy to install and maintain.
- Point to multipoint communication is possible.
- Satellite cost is independent of the distance.
- Sending and receiving information is independent of distance.
- 24 hours communication can be possible.
- High capacity in comparison to terrestrial networks.
- High-quality components are used to work in robust conditions and links are also designed to work in extreme weather conditions.
Disadvantages :
- Design, development, investment, and insurance of satellite requires higher cost.
- There can be a congestion of frequencies.
- propagation issues and interference may arise.
- Launching satellites into orbit is an expensive process.
- To reach the satellite from Earth, time can vary between 270 milliseconds and return again to 320 milliseconds. This propagation delay can cause an echo over telephone connections
- Satellites are not easy to repair and maintain.
- Some circumstances like weather or sunspots affect the satellite’s signal and can cause interference and make proper operation of the satellite very difficult.
- It requires to be monitored and controlled on regular periods so that it remains in the orbit, once it has been launched.
- Propagation delay of satellite system is more than that of conventional terrestrial system.
- Transmitter and receiver used in satellite communication requires high power and large diameter antennas.
- Due to aging effect the efficiency of satellite components decreases.
- Free space loss is more.