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WHAT IS DTH AND HOW IT WORKS

DTH MEANS “DIRECT TO HOME”.

DTH is a kind of a receiver which is used to receive the satellite program via individual antenna. The program is transmitted by the transmitter.

WHY DTH IS DISCOVERED?

This can be explained as, initially cables are required to transmit and receive the signal. In this process there are many losses with cables like noise affected, signal distortion, high cost because of many cables are used.
DTH is wireless communication. Small losses because No large no. of cables are required even not very costly.

HISTORY

The person who has invented the technology of DTH was “ARTHURE CLARLES CLARKE” British inventor in late 1946.
The DTH services is initially proposed in Pakistan in 2014, but was not approve due to concern over national security and some old cable operators.
Finally, now in 2016 the DTH services license is issued to four DTH operators in Pakistan.

MAIN UNITS / COMPLEXES OF DTH

  1. Broadcasting Center
  2. Satellite Encoder
  3. Multiplexers
  4. Modulators
  5. DTH Receiver

DTH NETWORK

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SATELLITE TRANSMITTER

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MINIDISH ANTENNA

It is parabolic reflector and it receives the signals and fed to the LNBF.
LBNF=LOW NOISE BAND DOWN CONVERTER
Which work as receiver for the transmitted signals by satellite transmitter.

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SIGNALS RECEIVED BY MINI DISH ANTENNA

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Signals is coming on the parabolic reflector and focused at the center of parabolic reflector where LNB is placed.

LNBF
Abbreviation as LOW NOISE BLOCK DOWN CONVERTER)
Properties

  • It collects signals from mini dish antenna.
  • It receives the signals from KU band and down converter to radio frequency signals.
  • It amplifies and remove the distortion from received signals.

BLOCK DIAGRAM

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SET TOP BOX

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The set top box can demodulate the signals and convert it into audio and video signals form.

SET TOP BOX UNDERSTANDINGS

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TUNER
It is used to select particular channel range from 48mhz to 840mhz.

DEMODULATOR
Selected channel’s signals demodulated and fed on decoder.

DECODER
It D to A convert which provides audio and video signals.

MICROCONTROLLER
It controls all the processes performed by the blocks.

DIFFERENCE BETWEEN CABLE AND DTH

  • In DTH TV, signals are directly transmitted via satellite to small dish antenna at subscriber’s home.
  • The broadcaster directly connected to subscriber so there is no local cable provider is present in this scenario.
  • The cable is limited for urban areas but DTH is also used in rural areas.
  • DTH can be work in any type of environment.

ADVANTAGES

  • As the DTH service is based on satellite and there is not requirement of wired signals like cable TV connections.
  • With DTH services anybody can get high quality digital signals on the television set.
  • DTH is very useful in the remote locations where the poor quality signals of television are found.
  • DTH also gives us best sound and clear picture quality.
  • The main benefit of DTH service is, it works on single channel and subscriber do not require to buy new television with more channels. We can change channel through the set-top box of DTH services.
  • The main advantage of DTH services, due to high quality picture and sound, we cannot get much stain on our eyes and ears.

DISADVANTAGES

  • In heavy rain we cannot get clear signals or no signal to view any channel. This is the major problem for the subscribers of DTH (Direct-To-Home) services.
  • Another major problem is that we cannot change our service provider. If any service provider gives us service badly and then 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.

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