SC Unit-I.ppt satellite communication intro
- 1. Satellite Communication Introduction Mrs. B.Prathyusha Asst. Prof. Department of ECE
- 6. Basic structure of satellite communication system
- 7. How a Satellite Works • A satellite is a body that moves around another body in a particular path. A communication satellite is nothing but a microwave repeater station in space. It is helpful in telecommunications, radio and television along with internet applications. • A repeater is a circuit, which increases the strength of the received signal and then transmits it. But, this repeater works as a transponder. That means, it changes the frequency band of the transmitted signal from the received one. • The frequency with which, the signal is sent into the space is called as Uplink frequency. Similarly, the frequency with which, the signal is sent by the transponder is called as Downlink frequency. The following figure illustrates this concept clearly.
- 9. Advantages of Satellite Communications • Broad cast to very larger area Cost effective as it can reach large number of customers. Communication to/from unreachable areas. • Reliable solution to last mile problem No need to get govt.permission to dig the roads. • Quick set up time with bandwidth on demand Use for Disaster to defense. • Provide fairness of service as demanded Diverse user network. • Long Life(12 to 20 Years) Very little maintenance.
- 10. Applications of Satellite Communication: Satellite communication plays a vital role in our daily life. Following are the applications of satellite communication − •Radio broadcasting and voice communications •TV broadcasting such as Direct To Home (DTH) •Internet applications such as providing Internet connection for data transfer, GPS applications, Internet surfing, etc. •Military applications and navigations •Remote sensing applications •Weather condition monitoring & Forecasting
- 13. Active Satellite • Advantages Require low power earth station. Less expensive than passive system. Not open to random use Directly controlled by operators from ground • Disadvantages Need hi-reliable design to avoid disruption of service due to failure of electronics components on-board the satellites. Requirement of on-board power supply. Requirement of larger and powerful rockets to launch heavier satellites In orbit.
- 14. Satellite frequency bands L-band (1–2 GHz) Global Positioning System (GPS) carriers and also satellite mobile phones, such as Iridium; Inmarsat providing communications at sea, land and air; World Space satellite radio. ... C-band (4–8 GHz) ... X-band (8–12 GHz) ... Ku-band (12–18 GHz) ... Ka-band (26–40 GHz)