Satellite communication uses satellites as relay stations to transmit radio and television signals between Earth stations. There are over 750 communication satellites currently in orbit. They provide wide area coverage, transmission regardless of distance, and a transmission delay of about 0.3 seconds. Common types are fixed satellites for point-to-point communication, broadcast satellites for television/radio, and mobile satellites for satellite phones. Satellites can be in low, medium or geostationary orbits depending on their purpose and coverage needs. Frequency bands like C-band, Ku-band and Ka-band are used depending on the satellite type and application.

1. Satelitecommunication

2. TEAM MEMBERS SONU PAULSON SYAM KUMAR.K SINTO C.J SYED MOHAMMED RAHIL SHERIN JOBY SHAMEEM SARATH.K.S THAMEEM ANSAR THACHILATH MOHANDAS VISHNU REUBEN THOMAS RASIM UL HAQE

3. Topics of Presentation Introduction Launching Satellites Applications How itworks Frequency Bands

4. TELECOMMUNICATION FSS = Fixed Satellite ServiceMSS = Mobile Satellite Service

6. There are about 750 satellite in the space, most of them are used for communication.

7. They are:Wide area coverage of the earth’s surface. Transmission delay is about 0.3 sec. Transmission cost is independent of distance.

9. A communication satellite is a station in space that is used for telecommunication, radio and television signals

11. The two stations can use a satellite as a relay station for their communication

12. One Earth Station sends a transmission to the satellite. This is called a Uplink.

14. The coverage area of a satellite greatly exceeds that of a terrestrial system.

15. Transmission cost of a satellite is independent of the distance from the center of the coverage area.

16. Satellite to Satellite communication is very precise.

18. Launching satellites into orbit is costly.

19. Satellite bandwidth is gradually becoming used up.

21. Fixed Service Satellites (FSS)

22. Example: Point to Point Communication

23. Broadcast Service Satellites (BSS)

24. Example: Satellite Television/Radio

25. Also called Direct Broadcast Service (DBS).

26. Mobile Service Satellites (MSS)

28. GEO

29. LEO

30. MEO

31. MOLNIYA

34. GEO satellites have a 24 hour view of a particular area.

39. LEO satellites have to compensate for Doppler shifts cause by their relative movement.

42. S-Band: 2 to 4 GHz, used by MSS, NASA, deep space research

43. C-Band: 4 to 8 GHz, used by FSS

44. X-Band: 8 to 12.5 GHz, used by FSS and in terrestrial imaging, ex: military and meteorological satellites

45. Ku-Band: 12.5 to 18 GHz: used by FSS and BSS (DBS)

46. K-Band: 18 to 26.5 GHz: used by FSS and BSS

48. C-Band occupy 4 to 8 GHz frequency:- Low frequency.- Large antenna (2-3 meters).

50. CDMA : (Code Division Multiple Access) Combination of time/frequency multiplexing ( a form of spread spectrum modulation). It provides a decentralized way of providing separate channels without timing synchronization. It is a relatively new scheme but is expected to be more common in future satellites.

51. Launching Satellites How does a satellite stay in it’s orbit?

53. Televesion & Radio- e.g. Direct broadcast satellite (DBS) & Fixed service satellite (FFS).

55. Internet- High Speed. - Useful for far away places.

57. Atmosphere behaves as a resistive medium- Supplies noise power to the antenna.

58. Meteors- Have to be programmed to avoid any rock or any harmful thing. - Rules of orbits.