Direct to home technology

WELCOME TO THE SEMINAR

ON

Direct to home television

Md. Arif Hussain

110301ECR072

Introduction

The overall system

Advantage of DTH

Limitation of DTH

Conclusion

What I will cover !!!

Direct to home (DTH) television is a wireless systemfor delivering television programs directly to theviewer’s house.

In DTH television, the broadcast signals aretransmitted from satellites orbiting the Earth to theviewer’s house

The DTH provides more than 200 televisionchannels with excellent quality of reception alongwith teleshopping, fax and Internet facilities.

Satellite television solves the problems of range anddistortion by transmitting broadcast signals fromsatellites orbiting the Earth

Introduction

There are five major components involved in a directto home (DTH) satellite system: the programmingsource, the broadcast center, the satellite, the satellitedish and the receiver

The Overall System

The programming source are simply the channels thatprovide programming for broadcast

Satellite TV provider get programming from two majorsource: International Channels(such as HBO,ESPN &CNN)&various Local Channels(Sahara TV,Doordarshan ).

The Programming Source

At the broadcast center, the television providerreceives signals from various programming sourcesand beams a broadcast signal to satellites ingeostationary orbit.

The broadcast center converts all of this programminginto a high-quality, uncompressed digital stream.

At this point, the stream contains a vast quantity ofdata about 270 megabits per second (Mbps) for eachchannel.

In order to transmit the signal from there, thebroadcast center has to compress it.

Otherwise, it would be too big for the satellite tohandle

Broadcast Centre

Broadcast Centre

Multiple

xer

Modulation

Encryption

Transmission

Encoder(MPEG-

2)

Receiving Terminal

Receiving Terminal

Dish

Antenna

Interface Cable

Set Top Box

LNB Feed system

The curved dish focuses incoming radio waves onto the feed horn.

Dish Antenna

LNB Feed System

The central element in the feed horn is low noise block-down converter.

Block-down convertor (so called because it converts a whole band or ‘block of frequencies’ to a lower band) i.e. it converts the 12.2 to 12.7 GHz band to 950 to 1450 MHz

SET TOP BOX

The basic Set Top Box (STB) takes the signal from the satellite dish and converts it into a signal that can be used by a TV, sound amplifier, etc.

Demodulation Digital

Demultiplexing

MPEG

DecoderDAC

Advantages of DTH

DTH offers better quality picture than Cable TV.

DTH can reach remote areas where terrestrial transmission and cable TV have failed to reach.

DTH also allows for interactive TV services such as movie-on-demand ,games and internet

Under unfavorable climatic conditions the service remains unavailable.

The service is interrupted in case if the direction of dish is disturbed.

Limitation of DTH

Direct To Home Technology connects urban , rural andremote areas of the country and provide desireinformation, communication, education and entertainmentat the click of button.

Conclusion

References

http://www.dth.com/

http://www.dthindia.com/

http://en.wikipedia.org/wiki/Direct-broadcast_satellite

http://www.ddindia.gov.in/

Thank You

Any Questions??