1.
DTH
Direct to Home
Seminar presentation
Enfa Rose George
RET16IT032
S1 Information Technology
Rajagiri School Of Engineering And Technology

2.
What do you
understand by DTH?

3.
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

4.
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 2006
Tata 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 Satellite
9 Zing Digital January 2015 Dish TV

5.
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

6.
DTH-Direct to Home
DTH refers to the reception
of satellite signals on a TV
with a personal dish in an
individual home

7.
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

8.
How does it work?
Different Channels
Etc
Asianet
HBO
DTH service
Providers
Home User(You
& Me)

9.
Basic Principle
https://www.youtube.com/watch?v=mdtBsZKjPNY

10.
Main components
• Programming Source
• Broadcasting center
• Satellites
• Encoders
• Multiplexers
• Modulators
• DTH receivers

11.
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

12.
Broadcast Center
• Central Hub of the system
• Uses MPEG2 technology for compression
– compressing 270 Mbps to 3 or 10 Mbps

13.
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

14.
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

15.
Low Compression High Compression

16.
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).

17.
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.

18.
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.

19.
•The encoder encodes the signals to
transmit the signals.
Encoder

20.
Satellites
•The satellite receives the signal
from the broadcast center
•Compresses the signals
•Makes them suitable for re-
transmission to the ground

21.
DTH RECEIVERS

22.
• Block diagram can be divided to two sections
Outdoor
unit Indoor unit

23.
Outdoor unit
Parabolic
Satellite
Antenna
LNA Converter

24.
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.

25.
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.

26.
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.

27.
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

28.
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

29.
• 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

30.
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

31.
Limitation
• Effects caused by rain, storm, hail, snow
etc.
• Greater interference in bad weather

32.
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

33.
Books
• Modern Television Practice by R R Gulati
• Satellite communication by Timothy Prath

34.
Check out these videos
• https://www.youtube.com/watch?v=TgeGYd3ujdo
• https://www.youtube.com/watch?v=mdtBsZKjPNY