1. SATELLITE TELEVISION BY- HARSHAL RAJGOR ISHANI PARIKH KINNARI PANCHA L

2. Satellite tv is delivered by the means of communication satellite and received by an outdoor antenna. In many areas of world satellite tv provide a wide range of channel and services,often to areas that are not serviced by terrestrial or cable providers. Satellite TV systems also transmit and receive radio signals using specialized antennas called Satellite Dishes.

3. Satellite tv's history stretches back to 1945 when Arthur C.Clarke proposed,that by placing 3 spaced platform into special orbit 22,300miles above equator,world wide communication were possible. The first Satellite tv signal was relayed from Europe to Telstar satellite over North America in 1962.

4. Problems related to Broadcast t.v Range Distortion Satellite t.v solves the problem of range and distortion by transmitting broadcast signal from satellite orbiting the earth.

6. TV satellites are all in geosynchronous orbit. Launched into space about 7000 mph reaching approx. 22,200 miles above earth. This speed and altitude will make satellite revolve around the planet every 24 hrs. Due to this you only have to direct the dish at the satellite once, and then pick up the signal without adjustment.

7. Most satellite TV customers get their programing through a Direct Broadcast satellite (DBS) provider such as DirecTV OR DISH network. The provider selects program and broadcasts them to subscribers as a set package. The provider’s broadcast is completely digital. Earlier satellite TV was broadcast in C-band radio in 3.7 GHz-4.4GHz. DBS transmits programming in Ku frequeny range. (11.7-14.5 GHz).

8. Programming sources. Broadcast center. Satellite. Dish. Receiver.

9. Satellite providers get programming from 2 major source - National Turnaround channels and various Local channels. Turnaround channels have a distribution center that beams their programming directly to geosynchronous satellite; while the local stations don't transmit. To provide local signals in package,service provider set up some communication equipments which receives the signals directly from broadcaster through fiber-optic cables and then transmits to central broadcast center. Broadcast center converts all this programming into a high quality,uncompressed digital stream.

10. Compression means removal of unnecessary or repetitive information from the signal before transmission. Satellite t.v uses video file compression standardized by MPEG. With MPEG compression,provider can transmit significantly more no.of channels. At present Satellite t.v use MPEG-4 compression, which provides high-definition of quickly moving objects that constantly change place and direction on the screen.

11. Encoding works in conjunction with compression. Overall size of file is reduced. There are 3 ways to encode:- a) Intra-frame-contains complete image data. b) Predicted frame-how the picture has changed from previous frame. c) Bi-directional frame-use data from closest frames and the receiver interpolates the position and color of each pixel.

12. After compression, the provider encrypts it to keep people from accessing it for free. Encryption scrambles the digital data which can be decrypted only if the receiver has correct decryption algorithm and security tips. Once the signal is compressed and encrypted the broadcast center beams it directly to one of its satellites.

13. It is special type of antenna to focus on specific broadcast source. It consists of a parabolic surface and a central feed horn. To transmit a signal,a controller sends it through the horn and the dish focuses the signal into a relatively narrow beam. In receiving antenna,when the beam hits the curved surface,it reflects the signal and focuses on feed horn,which transmits the signal on to the receiving equipment. The central element in feed horn is LNB.

14. Satellite t.v in India dates back to Jan 1991 when translational satellite broadcasting debuted in India with reception of CNN covering the Persian Gulf War. In India, DTH and satellite t.v is a recent phenomenon.The key players are DishTv and TATASKY.

15. The end component in the entire TV system. It has 4 essential jobs: It de-scrambles the encrypted signal. It takes the digital MPEG-2 or MPEG-4 signal and converts it into an analog format that a standard television can recognize. It extracts the individual channels from the larger satellite signal. It keeps track of pay-per-view programs and periodically phones a computer at the provider's headquarters to communicate billing information.

16. 1. Direct Broadcast via Satellite: Also known as “Direct -To-Home”. Refers to communication satellite themselves or actual television service. DBS system commonly known as “mini-dish systems”. Uses upper portion of Ku and Ka band. If modified can run on C-BAND satellites.

17. In 1978 MICROCOMM, a small company introduced 1 st commercial satellite TV receiver. Designed to receive analog and satellite feeds of both television or audio. TVRO systems tend to use larger than smaller satellite dish antenna. SIMULSAT is a quasi-parabolic satellite earth station antenna.

18. Satellite TV offers movie-quality, audio and picture display with hundred of channels. The service is available in urban and rural areas. It also provides access to more digital and High Defination Programing.

19. It is expensive as we will have to purchase all equipments at the outset. If we want access to satellite TV in multiple rooms the cost will increase further. Satellite TV is subject to weather related malfunctions.

20. Satellite t.v systems seems most appealing to person's who either are disenchanted with cable t.v or who lives in areas that are not served by cable. These systems operate with small antenna and low cost receiving systems. Very large no.of video and audio channels. Delivery of bit stream through broadcast satellite can be adapted to serve internet users who require the download of large data. Both DirectTv and DishTv offer internet access terminals with uplink capability.

21. www.wikipedia.org www.howstuffworks.com