1. Power Point presentation on DTH
Presented by :-
veerendra kr. Verma
RollNo

2. Contents:- 1.Introduction 2.Basic network of DTH 3.Parts of DTH
4.Working of DTH
5.Broadcasting center
6.Receiving station
7.Set top box
8.Benefits of DTH
9.conclusoin

3. Introduction DTH stands for DIRECT-TO-HOME television
DTH is defined as:
The reception of satellite programmers 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

4. Network of DTH

5. Dth consist of three main parts
Programming source
Broadcasting center
Satellite
Dish
The receiving terminal

6. Working of DTH
The DTH utilizes a technology which enables a home to receive video channel with a suitable set capable of demodulating mpeg-2 (4) standard video channel with a suitable set top box
The DTH service provider has to lease ku band transponders from the satellite .
DTH does away with the need of local cable operator and put the broadcaster directly in touch with consumer.

7. The programming source are simply the channels that provide programming for broadcast.
The provider doesn't create original programming Itself; it pays other companies(HBO, ESPN etc)
Satellite TV provider get programming from two major source; international turnaround channels (such as HBO,ESPN&CNN) &various local channel ( sahara TV,doordarshan etc ).
Turnaround channels usually have a distribution center that beams
there programming to a geostationary satellite .the broadcast
uses large satellite dishes to pick up these analog & digital signal from
several sources .

8. Broadcasting center (Central hub of the system) Encoders multiplxers
Satellite
Modulators

9. Broadcast center Encoder (MPEG-2) Multiplexers Mixes these signals
The broadcast center converts all of this programming into high quality, uncompressed digital stream. At this point the stream contains a vast quantity of data about 270 mbps for each channel .
In order to transmit the signal from there, the broadcast center has to compress it.
Encoder (MPEG-2)
The base analog or the high quality digital video- audio are converted to the DVB standards of correct size and format .
With digital compression the satellite can transmit about 200 channels .
Multiplexers
Mixes these signals

10. Modulation Encryption Transmission
The modulation converts the message signal into a form that is suitable for transmission over communication channel. This involve varying some parameters of a carrier wave in accordance with the message signal.
Encryption
After the video is compressed, the provider needs to encrypt it in order to keep people from accessing it for free. Encryption scrambles the digital data in such a way that it can only be decrypted if the receiver has correct decoding satellite receiver with decryption algorithm and security keys
Transmission
Once the signal is compressed and encrypted, the broadcast center beams it directly to one of its satellite. the satellite pick up the signal amplify it & beams back to earth where viewer can pick it up .

11. Receiving station ( for the reception of the signal being beamed from transmitted station)
Receive type solid offset antenna
Set top box
LNB feed system
Interface cables

12. Feed horn Receive type solid offset antenna
When a beam hits the curved dish, the parabola shape reflects the radio signal inward onto a particular point, just like a concave mirror focuses light onto a
particular point.
The curved dish focuses incoming radio waves onto the feed horn. In this case, the point is the dish’s feed horn, which passes the signal onto the receiving equipment.

13. low noise blockdown converter, or LNB.
The central element in the feedhorn is low noise blockdown converter
Low Noise Block-down convertor (so called because it converts a whole band or “block” of frequencies to a lower band).
An LNB sits on the end of an arm and faces the parabolic reflector (“dish”) which focuses the signals from a satellite into the “feed horn” of the LNB (see pictures below). The LNB converts the signals to a lower frequency and sends them out to the cable connector, which you connect to your satellite receiver via coaxial cable.

14. Lnb amplifies the radio signal bouncing off the dish and filter out noise (radio signal not carrying programming and also converts the ku band frequency into if bassed on local if
LNB
Universal LNB
“Universal” ku band LNB is available that can switch electronically between and GHz frequency spectra to provide complete coverage of entire ku- band frequency range.
The receiver send switching voltage (13 or 17 V dc ) to the LNB that automatically changes the LNB input frequency range to the desired frequency spectrum.

15. Set top box (STB)
Demodulation
Digital demultiplexing
Mpeg decoder
DAC
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

16. Digital demultiplexing
Demodulation
the process of conversion of signal into its original form transmitted at the transmitter is called demodulation .
Digital demultiplexing
After Qpsk demodulation the digital bit stream contain several multiplexed Channel as well as error control bits. The bit stream is processed to correct and detect error , de interleaved and decrypted. The digital demultiplexer then extracts the bits for wanted channels.
Mpeg decoder
It de-scrambles the encrypted signal. In order to unlock the signal, the receiver needs the proper decoder chip for that programming package (smart card having correct keys for decryption is required to view paid channels )
The provider can communicate with the chip, via the satellite signal, to make necessary adjustments to its decoding programs.
DAC
The DAC finally generates analog audio and video signals to derive TV sets

17. Benefits of DTH Conclusion
Cost effective communication, information and entertainment to all
Small size terminal can provide up to 4000 channels through a click of button and thus bring worlds information , news entertainment to your home
DTH services bypasses mediators and thus content provider comes with customer directly .
DTH services are transparent providing digital quality video , audio, radio, and IP to all at equal prices and other benefits with reliabilty
Conclusion
Direct to home connects urban , rural and remote areas of the country and provide desire information, communication, information, education and entertainment at the click of button.
It helps in improve economy of country

18. Conclusion
Direct to home connects urban , rural and remote areas of the country and provide desire information, communication, information, education and entertainment at the click of button.
It helps in improve economy of country

19. Thank you