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satellite communication & DTH

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satellite communication & DTH

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a seminar presentation on satellite communication & DTH with all the key point covered under this ppt with a small video attached in one of the slides inside this presentation.

a seminar presentation on satellite communication & DTH with all the key point covered under this ppt with a small video attached in one of the slides inside this presentation.

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satellite communication & DTH

  1. 1. & DTH PRESENTED BY :- Siddhartha gupta EC-3rd yr 1402931156
  2. 2. TOPICS OF PRESENTATION INTRODUCTION WORKING TYPES OF ORBITS ADVANTAGES DISADVANTAGES COMPONENTS OF DTH WORKING OF DTH SET TOP BOX APPLICATIONS CONCLUSION LATEST SCENERIO REFRRENCES
  3. 3.  A satellite is simply any body that moves around another (usually much larger) one in a mathematically predictable path called an orbit. OR A satellite is a solid object which revolves around some body due to the effect of gravitational forces.  The first man made satellite with radio transmitter was in 1957  There are about 750 satellites in the space, most of them are used for communication
  4. 4. 18-Sep-17 satellite communication 5 What is Satellite communication ?
  5. 5.  Two Stations on Earth want to communicate through radio broadcast but are too far away to use conventional repeater.  The two stations can use a satellite as a relay station for their communication  One Earth Station transmits the signals to the satellite. Up link frequency is the frequency at which Ground Station is communicating with Satellite  The satellite Transponder converts the signal and sends it down to the second earth station. This frequency is called a Downlink frequency
  6. 6. 18-Sep-17 satellite communication 8Wired satellite communication  BASIC BLOCK DIAGRAM OF SATELLITE COMMUNICATION
  7. 7. TRANSPONDER
  8. 8. C BAND:-  C-band is the most common frequency spectrums used by today’s satellite.  C-band satellite transmission occupy The 4 to 8GHz frequency Range.  C-band antennas is approximately 2-3 meters in diameter.
  9. 9.  KU-BAND :  KU-band satellite transmission occupy the 13 to 18 GHz frequency range.  KU-band antennas can be as small as 18 inches in diameter.  these very high frequency transmission mean very small wavelenghts and very small diameter receiving antennas.
  10. 10. Types of orbits…  Geosynchronous  Same rotational velocity as earth  Maintains position relative to earth  Altitude - 35 786 km  Velocity - 11 300 km/hr  Asynchronous  Much lower altitude = much higher velocity  Position over earth constantly changing Contd….
  11. 11. DIRECT TO HOME SERVICE(DTH)
  12. 12. 19 What is DTH ? DTH is defined as:  The reception of satellite programs with a personal dish in an individual home.  DTH does away with the need for the local cable operator and puts the broadcaster directly in touch with consumer .  A wireless digital audio / video service is delivered through satellite.
  13. 13. 1996 : DTH services were first proposed in India 2000: DTH was allowed with new policy The operators were required to setup earth stations in INDIA within 12 month for getting license of broadcasting whose cost was $2.14 million and will be valid for 10 years.
  14. 14. MAIN COMPONENTS OF DTH:-  Broadcasting center  Satellites Encoders  Multiplexers  Modulators  DTH receivers.  The broadcast centre is the main part of the whole system. It is from the broadcast station that the signals are sent to the satellites to be broadcasted. The broadcast station receives the signals from various program channels.
  15. 15. CONTD ...  The satellite receives the signal from the broadcast centre and compresses the signals and makes them suitable for re-transmission to the ground.  The DTH providers give dish receivers for the viewers to receive the signal from the satellites. There may be one or multiple satellites that send the signals at the same time. The receiver receives the signal from them and is passed on to the Set Top Box [STB] receiver in the viewer’s house.  The STB receiver changes the signal in a form suitable for our television and then passes it on to our TV.
  16. 16. A DTH ALSO CONSISTS OF :-  MINIDISH ANTENNA  LNBF  COAXIAL CABLE CONNECTOR SET TOP BOX Minidish antenna LNBF CONNECTOR
  17. 17. LNBF  LNBF is a part of a satellite antenna which is positioned In front of the dish to recieve the signal and converts the Signal to be carried by cable to the reciever.  low noise block down converter is the antenna of a what is commonly called the parabolic satellite dish commonly used in satellite TV reception.
  18. 18. SET TOP BOX • A set top box(STB) or Set top unit (STU) is a Device that connects to A television and an External source of signal, Turning the signal into Content which is then Displayed on the television Screen.  i/p voltage range:- 90-250V AC  freq connectors:- 50Hz ± 5%
  19. 19. ENC1Enc1 ENC 22 MUX  QPSK modulator   Service uplinked To satellites Services downlink via receive satellite dish and fed into STB Content “on demand” servers BASIC BLOCK DIAGRAM OF DTH:-
  20. 20. OPERATION ...  The block diagram of DTH TV system is divided into two sections:- 1) OUTDOOR UNIT 2) INDOOR UNIT  OUTDOOR UNIT • The outdoor unit consists of:- 1) THE PARABOLIC REFLECTOR ANTENNA 2) LOW NOISE AMPLIFIER (LNA) 3) CONVERTER
  21. 21. CONTD... • The receiver antenna is a parabolic reflector horn antenna which is directed directly to the satellite to receive the signal. • the received signal from satellite by the antenna is applied to the low noise amplifier(LNA) which is a wide band amplifier. • LNA amplifies all the frequencies received from the antenna and applies them to a converter. The second input to this converter is from the local oscillator 1. • the converter output consists of a UHF signal having a frequency range from 950-1450 MHZ with a bandwidth of 500MHZ. • the output of converter is applied to the RF amplifier.
  22. 22. INDOOR  It consists of a RF amplifier which is applied to a channel selector to select the desired channel with the help of a mixer & local oscillator too.  An IF frequency of 70MHZ is produced,  The RF amplifier applied these to video-audio detector which separates the video , audio & synchronous pulses.  the TV receiver then works as usual.  A DBS(directly broadcast satellite ) concept is used in DTH system.
  23. 23. 30 0.06 0.18 0.75 1.925 4.8 9.8 15 20.9 26.1 30.4 33.8 36.2 37.6 0 5 10 15 20 25 30 35 40 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Year Subscribers(Millions) GROWTH OF DTH USERS 2007 to 2015…Growth of 683 %
  24. 24. DTH Vs CABLE TV DISH TV(DTH) CABLE TV  Dish networks features, HD, CD sound superior picture quality with huge nos of channel access.  dish TV has remote Geographical access with Limited installation.  special features – recording, play games , study ads for childrens, and language home tutorial packages.  Average accessed quality of sounds & pictures ,limited number of channel accessed.  cable for subscriber is a limited to wire but major to the supplier with huge installation.  cable TV had manual access with least features but with cable modem net.
  25. 25. ADVANTAGES OF SATELLITE OVER TERRESTIAL COMMUNICATION  The coverage area of a satellite greatly exceeds that of a terrestial system.  Transmission cost of a satellite is independent of the distance from the centre of the coverage area.  satellite to satellite communication is very precise.  Higher bandwidths are available for use.
  26. 26. ADVANTAGES OF DTH:-  With DTH service we can get direct television services to our home which can be situated anywhere.  As the DTH service is based on satellite and there is not requirement of wires signal like cable TV connection anywhere in the country.  DTH also gives us the best sound and picture quality.  With DTH service we can select the channel programs as our choice.  We can pay the subscription fee online through net banking , voucher recharge or credit card.
  27. 27. DISADVANTAGES OF DISH TV(DTH):-  During heavy rain we cannot get a clear signal. This is the major problem for the subscribers of DTH service.  Another major problem is that we cannot change our service provider. Eventhough , if any service provider gives us service badly we cannot shift to another as the set top box settings are only linked with the same service provider . If we want to change the service provider then we should need to pay additional cost to buy new set top box from new service provider.
  28. 28. CONCLUSION:-  DTH has made the hopes of the people of rural areas to come true.  DTH service in India is in initial stage delivering only TV broadcasting.  It provide the wide thinking of rural people which helps to develop the culture of society ..
  29. 29. REFRECNES:-  https://www.wikipedia.com  https://www.linkedin.com  http://onlinelibrary.wiley.com  http://www.academia.edu  https://www.ieee.org  https://www.TUTORvista.com

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