DTHDirect to Home

Seminar presentationEnfa Rose George

RET16IT032S1 Information Technology

Rajagiri School Of Engineering And Technology

What do you understand by DTH?

History

•Sir Arthure Clarles Clarke in 1946 invented DTH technology•First proposed in India in 1996 , but unapproved due to concern over national security.• In 2000, DTH service was allowed •Doordarshan was first to provide the service

Sl.no

Service provider Launch date Ownership

1 Dish TV 2 October 2003 Zee Entertainment Enterprises

2 DD Free Dish December 2004 Prasar Bharati

3 Tata Sky August 2006Tata Sons (60%)21st Century Fox (30%)Temasek Holdings (10%)

4 Sun Direct 2007 Sun Network (80%)Astro Group (20%)

5 Airtel digital TV 2008 Bharti Airtel Limited

6 Reliance Digital TV August 2008 Reliance

Communications

7 Videocon d2h June 2009 Videocon Group

8 ABS Free Dish 2012 Asia Broadcast Satellite9 Zing Digital January 2015 Dish TV

HD and ULTRA HD

• Sun Direct is the first DTH provider to offer high-definition (HD) channels in early 2010. • Videocon d2h began offering a preview

of 4K Ultra HD content on its DTH service in July 2014

DTH-Direct to Home

DTH refers to the reception of satellite signals on a TV with a personal dish in an

individual home

Features of DTH

• Exceptional picture and sound quality .• MPEG4 with DVB-S2 digital transmission that has

the provision of HD quality. • Pay only for the channels and services you want• It provides Advanced Viewing Control Features

Ex: Electronic Program Guide (EPG) • Applications such as Parental Lock, Pre-booked

Pay-Per-View and Impulse Pay-Per-View

How does it work?

Different Channels

Etc

Asianet

HBO

DTH servic

e Providers

Home User(You & Me)

Basic Principle

https://www.youtube.com/watch?v=mdtBsZKjPNY

Main components

• Programming Source• Broadcasting center• Satellites • Encoders•Multiplexers•Modulators •DTH receivers

Programming source

• Channels that provide programming for Broadcast• It pays other companies for right to broadcast their channels• Intermediate between Actuals broadcasters and Home viewers

Broadcast Center

• Central Hub of the system•Uses MPEG2 technology for compression – compressing 270 Mbps to 3 or 10 Mbps

MPEG2 Technology

• Standard for "the generic coding of moving pictures • ISO/IEC 13818 MPEG-2 at the ISO Store.• A combination of lossy video compression and lossy audio data compression methods• Permit storage and transmission of movies using currently available storage media and transmission bandwidth

Lossy compression Irreversible compression

• Class of data encoding methods that uses inexact approximations and partial data discarding to represent the content.• These techniques are used to reduce data size for storage, handling, and transmitting content

Low Compression High Compression

Kurtz-under band

• Satellite communication works in the Ku Band• The Ku band is primarily used for satellite communications• Particularly for editing and broadcasting satellite television. • 11.7 to 12.7GHz. (downlink frequencies)• 14 to 14.5GHz (uplink frequencies).

Multiplexer:

•Device which transmits the information of many channels in one channel.• The multiplexer is built in the broadcasting center. • Compresses all the frequency signals into one single channel & transmits it to the Geo-Stationary satellite.

Modulator:

•Modulation is a process in which the information signal is imposed on a carrier signal which is of high strength.•This process is done in the modulator. •The modulator modulates the signals and sends to the encoder.

•The encoder encodes the signals to transmit the signals.

Encoder

But why encode?

Satellites

•The satellite receives the signal from the broadcast center•Compresses the signals•Makes them suitable for re-transmission to the ground

DTH RECEIVERS

• Block diagram can be divided to two sections

Outdoor unitIndoor unit

Outdoor unit

Parabolic Satellite Antenna

LNA

Converter

Parabolic Satellite Antenna

•Directly Directed to the satellite to receive signals• The reflector's surface material must be constructed out of metal• Installation errors almost never occur when this type of antenna is assembled face-down on a flat, level surface.

LNBF

• Part of antenna positioned in front of dish to receive signal and converts signal to be carried by signal to receiver• Low noise block down converter is the

antenna• Converts all signal from KU to L band• LNA amplifies all frequencies and

applies them to converter.

LNBFcont…

• The incoming satellite signal propagates down the waveguide of the feed horn• Exits into a rectangular chamber

mounted at the front of the LNB,• The tiny resonant probe in the LNB, this

is a pickup probe• Wavelength resonates with the incoming

microwave frequencies• Conducts the signal onto the first stage

of electronic amplification.

Indoor unit

• RF amplifier which is applied to channel selector to get to get desired channel with help of mixer and local oscillator• An IF Frequency 70 MHz is produced

Set top box

• Information appliance device• Contains a TV-tuner input•Displays output to a television set and an external source of signal•D to A Conversion• Turning the source signal into content in a form that can then be displayed on the television screen

• The broadcaster directly connects to the user.• Reach the remotest of areas• DTH enables a viewer to move

from one city to another without changing the STB• Offers better quality picture• Digital• Interactive TV services

DTH CABLE TV• There are middle men

like local cable operators• Wires and cables restrict

reachability• Change of cable operator

from region to region• Lesser Quality• Analog• Just TV

Advantages

• Technology equally beneficial to all…urban or rural. •High quality audio and video • Cost effective due to absence of mediators. • Almost 4000 channels + 2000 radio channels. • Complaints directly expressed to the provider. •With a single DTH service you will be able to use digital quality audio, video and also high speed broadband.

Limitation

• Effects caused by rain, storm, hail, snow etc.•Greater interference in bad weather

References• http://www.circuitstoday.com/direct-to-home-dth-technology-

%E2%80%93-working• www.dth.co.in• http://www.intelsat.com/wp-content/uploads/2016/03/Intelsat-DTH-5457-wp.pdf

• http://www.preservearticles.com/2012032027846/what-is-dth-technology.html

• http://www.tech-faq.com/ku-band.html

Books• Modern Television Practice by R R Gulati• Satellite communication by Timothy Prath

Check out these videos• https://www.youtube.com/watch?v=TgeGYd3ujdo• https://www.youtube.com/watch?v=mdtBsZKjPNY

Any Questions?