DTH (Direct To Home) television is a technology that allows people to receive satellite TV programs using a personal dish antenna installed at their home. It was originally called Direct Broadcast Satellite technology. DTH services were first proposed in India in 1996 but did not pass approval until 2000 due to concerns over national security and cultural invasion. The major components of a DTH network are a satellite, DTH dish antenna, and set top box.

2.  DTH stands for Direct To Home television.
 DTH is defined as the reception of satellite programmes with a
personal dish in an individual home.
 This technology is originally referred to as Direct Broadcast
Satellite (DBS) technology.
 DTH is a new technology & it has matured to its full potential in
other parts of the world.

3.  On June 25, 1967 the London-based production, was the first-ever use of
satellites to simultaneously interconnect remote corners of the world to a single
program event.
 The program, appropriately entitled "Our World," included the Beatles
debuting the song "All You Need Is Love" to an audience estimated at more than
600 million.
 During the course of the telecast, live feeds were interconnected through a
pair of early design Intel sats, an American experimental satellite (ATS-1), & a
Russian Molniya class bird.

4.  DTH services were first proposed in India in 1996.
 But they did not pass approval because there were concerns over
national security & a cultural invasion.
 Finally in 2000, DTH was allowed.
 The operators were required to setup earth stations in India within 1 yr
for getting license of broadcasting whose cost was ` 10.7 Crores & will be
valid for 10 yrs.

5. • A DTH network consists of
– Satellite
– Multiplexers
– Orbital Location
– Dish Antenna
– Set Top Box
– Demultiplexers
– TV

6. Satellite
 The television satellites are all in geosynchronous orbit
which is 22,200 miles (35,700 km) above the Earth
 The satellite receives the signals from the source i.e., the
TV station.
 Then the satellite sends the signals to the DTH antenna
on the earth.
Dish
 Every individual user has a small dish usually 45 to
60cm in diameter.
 It is a parabolic dish made up of plastic (or)
fiberglass.

7. LNB
 A Low Noise Block down converter (or LNB) is the
receiving device of a parabolic satellite dish antenna of the
type commonly used for satellite TV reception.
 The incoming satellite signal propagates down the
waveguide of the feed horn & exits into a rectangular
chamber mounted at the front of the (LNB).
Set Top Box
 The set top box accepts the entire down converted
band & separates out the individual transponder
frequency.
 Then signals are first converted to fixed IF & then
QPSK demodulated.
 A digital demultiplexer then extracts the bits for wanted channel, & sends them to MPEG
decoder, & finally generates analog Audio & Video signals with DIA converters to drive TV set.

8. • The DTH utilizes a technology which enables a home, to receive high
speed internet broadband access data communication, using an open
standard Digital Video Broadcasting (DVB) technology.
• The major components of a DTH network are
– Satellite,
– DTH (Parabolic Dish),
– STB (Set Top Box).

9.  A DTH service provider has to lease Ku-band transponders from the
satellite.
 The encoder converts the audio, video & data signals into the digital format
& the multiplexer mixes these signals.
 At the user end, there will be a small dish antenna & set-top boxes to
decode & view numerous channels.
 On the user's end, receiving dishes can be as small as 45-60 cm in diameter.
 The antenna sends the signals to the Set-Top box to demultiplex the
signals.
 The user can select the program of his wish using a remote.

10. Broadcaster
Multi Service Cable
Operator
(Siticable, Incable etc.)
Access Cable
Operators
Home
(TV)

11.  In DTH, TV channels would be transmitted from the satellite to
a small dish antenna mounted on the window or rooftop of the
subscriber's home.
 DTH can also reach the remotest of areas since it does away
with the intermediate step of a cable operator & the wires (cables)
that come from the cable operator to your house.
 Also, with DTH, a user can scan nearly 700 channels!

12.  One can scan the entire globe with a motorized dish using a CI set top
box with CAM modules and watch TV channels of several DTH platforms
visible to the dish terminals.
 A number has started IP broadcast with return channel on PSTN line
and this would be for education and other application.
 Cost effective communication, information and entertainment to all.
 DTH services bypasses mediators and thus content provider comes
with customer directly.

13.  DTH projects in India are just a beginning and we are taking the
advantage of DTH revolution.
 Direct to home connects urban, rural and remote areas of the country and
provides desire information communication, education and entertainment at
the click of a button.
 Narrow band noise can cause RFI, in spectral line observations below
400MHz, if located at about 2 km from a GMRT antenna.