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Vocational Training
Report
HELD AT
DOORDARSHAN
KENDRA
MANDI HOUSE, COPERNICUS MARG
NEW DELHI, 110001
SUBMITTED BY
S A K E T R A I
ECE 4th Year, Roll No. 1003031097
INDERPRASTHA ENGINEERING COLLEGE, GZB,
U.P.
ACKNOWLEDGEMENT
This report is an outcome of industrial training, which I
have gone through at Doordarshan Kendra, Mandi
House, Copernicus Marg, New Delhi, 110001; during the
period 10th Jun to 9th Jul 2013.
On the very outset of this report I would like to express
my sincere & heartfelt obligations to:
DDG (E): Shri Shyam Narain Singh,
DD (E): Shri Rakesh Kumar Chauhan,
Assistant Er. : Shri R. N. Rai (Mentor),&
All engg. Supporting staff: Sh. Vinod Gupta, Sh. S. K. Dixit, Sh.
S. P. S. Gulati, Sh. P. K. Mehrotra, Sh. P. Arun, Sh. Prashant
Shingle, Sh. Govind Ballabh, & Sh. T. C. Bagauli for creating
tremendous atmosphere of excitng training programme
at DDK.
It was really a great experience working at DDK and
learning from such experienced engineers with hands on
the experience on the subject.
I also would like to appreciate my colleagues Mr.
Prashant Kr. Shukla, Mr. Pulkit Jain & Mr. Rahul Aurora,
who attended the entire training with me as per the
scheduled by DDK.
Saket Rai
ECE 4th Year, 1003031097
INDERPRASTHA ENGG. COLLEGE, GZB, U.P.
INDEX
Sr. No. Topic Page No.
1. About Doordarshan 01- 02
2. TV Studio 03-06
3. Production Control Room 07-09
4. Transmission Control Room 10-12
5. Master Switching Room 13-14
6. Earth Station 15-19
7. Satellite Communication 20-24
8. HPT Pitampura 25-28
9. OB Van 29-32
10. DSNG 33-35
11. DD Archives 36-38
12. Essence 39-40
ABOUT ……..
DOORDARSHAN KENDRA DELHI is one of the oldest
Kendra started on experimental basis on 5th September
1959 from a makeshift studio at Akashvani Bhawan,New
Delhi as a part of All India Radio.
Regular transmission was started from 1965.
Govt. of India constituted Doordarshan in 1976, as a
public TV broadcaster, as a separate department in
broadcasting.
Actually, Doordarshan developed itself during Asian
Games 1982, held in Delhi.
Continuous development in each & every sections of
Doordarshan has made it one of the largest broadcasting
organization in the world in terms of infrastructure of
studios & transmitters.
Presently Doordarshan operates with 35 channel
classified as:
Seven All India Channels-
1. DD National,
2. DD News,
3. DD Sports,
4. DD Bharati,
5. DD Rajya Sabha,
6. DD Gyandarshan,
7. DD Urdu;
Eleven Regional Language Satellite Channels(RLSC),
Fifteen State Network (SN) & International Channels,
One DD India Channel,
One HDTV Channel;
Doordarshan is also providing multi channel TV coverage
in country through it’s free to air service; DD Direct Plus.
DD is also running a mobile television service in Delhi.
T V Studio
Doordarshan shooting arena is termed as TV Studio.
Basically, it is a production hall to shoot out various
programs by just creating artificial sets as per
requirements.
Followings are the pre- requisites for a TV Studio:
1. Lighting systems, winches & control boards
2. Cameras (3/4) with teleprompter
3. Video & Audio Monitors
4. Make room with entire facilities
5. Furnitures & decoration items
6. Cyclorama &curtains
7. Proper air conditioning systems
8. Efficient sound absorbers
9. Smooth & plain surface to move cameras
10. Effective communication with other sections
11. Digital clock display system
12. Warning light, alarm systems & fire fighting equipments.
Doordarshan’s main Recording TV Studio comprises 192
direct lights, 48 dimmers, 3 /4 digital cameras & 3 /4
artificial shooting sets etc.
T V Studio lighting technique:
T V Studio lighting technique depends upon following
four parameters -
1. Quantity of Iight:
Means amount of radiated energy by the source of
light. 2. Quality of light:
Means the type of light source is used.
3. Contrast ratio:
Difference between highly lighted & darkest part of
the scene.
4. Color temperature:
Different light colors have their own temperatures
e.g.-
Fire- 1930K,
Domestic lamp- 2780K,
Studio lamp- 3200K,
HMI-5600K,
Sun light- 5600K,
Fluorescent- 6500K,
Cloudy day- 6500K,
Clear blue sky-12000K.
In T V Studio standard three point lighting technique is
used, as shown below:
1. Key light: used to highlight an object from the front.
(Hard light cum 100% balance of light)
2. Fill light: used to suppress the shadow created by key
light. (Soft light cum 85% balance of light)
3. Back light: used to separate the object from back
ground, so to produce 3-D visualization.
(Hard light cum 110% balance of light)
Production Control
Room
Production Control Room (PCR) is also known as Studio
Control Room (SCR) or Gallery. Signals generated in TV
Studio are controlled using certain effects & characters
are generated here.
Facilities in a PCR include:
A video monitor wall, with monitors for program, preview, VTRs, cameras, graphics and other video sources. In some facilities, the monitor wall is a series of racks containing physical television and computer monitors; in others, the monitor wall has been replaced with a virtual monitor wall (sometimes called a "glass cockpit"), one or more large video screens, each capable of displaying multiple sources in a simulation of a monitor wall.
A vision mixer, a large control panel used to select the multiple-camera setup and other various sources to be recorded or seen on air and, in many cases, in any video monitors on the set. The term "vision mixer" is primarily used in Europe, while the term "video switcher" is usually used in North America.
A professional audio mixing console and other audio equipment such as effects devices.
A character generator (CG), which creates the majority of the names and full digital on-screen graphics that are inserted into the program lower third portion of the television screen
Digital video effects, or DVE, for manipulation of video sources. In newer vision mixers, the DVE is integrated into the vision mixer; older models without built-in DVE's can often control external DVE devices, or an external DVE can be manually run by an operator.
A still store, or still frame, device for storage of graphics or other images. While the name suggests that the device is only capable of storing still images, newer still stores can store moving video and motion graphics.
The technical director's station, with waveform monitors, vector scopes and the camera control units (CCU) or remote control panels for the CCUs.
In some facilities, VTRs may also be located in the PCR, but are also often found in the central apparatus room
Intercom and IFB equipment for communication with talent and television crew
A signal generator to genlock all of the video equipment to a common reference that requires color burst
TRANSMISSION
CONTROL ROOM
Transmission Control Room (TCR), also termed as Tx Room or Presentation Suites is a room at broadcast facilities & TV Stations around the world.
TCR is staffed 24x7 by on-air presentation coordinators who are responsible for the continuity and punctual play out of scheduled broadcast programming.
Programming may be live from the TV Studio or played from video tapes or from video server play out.
When broadcast programming is live the presentation coordinator will override the broadcast automation system & manually switch the TV Programming.
Live Programming is unpredictable and will affect the scheduled timing of scheduled programming events; the presentation coordinator adjusts programming to bring the schedule back on time by adding or removing fill content from the play out schedule.
Common TCR equipments
Broadcast Automation Server (for large playlist items
almost up to 500 items),
Video Tape Recorder (VTR),
Computer Graphics (CG),
Non-linear Editing device,
Production Switcher,
Broadcast quality Video Monitor,
Waveform Monitor,
SDI Audio de-embedder.
There are total 72 electronic equipments of
aforementioned type in the Transmission Control Room
of DD National.
Basically, the automation of various PCR equipments is
done in order to achieve seamless transmission. It is also
required to minimize the time elapse as well as manual
errors occurred during transmission.
Each & every equipment has its own defined port on
Production Switcher. Applying automation one can
switch the particular device at particular time.
Finally, these equipments are connected to a Navigation
PC through a Hub Switch for error diagnosis purpose.
TCR is smaller in size as compare to the Master Switching
Room. This is a scaled down version of centralcasting.
MASTER SWITHING
ROOM
Master switching room (MSR) is also known as “Heart of the Studio” and used for transmission media. It is the engineering co-ordination center of activity for selecting & routing the signal from various sources to transmitter and earth station. It is a room where all different sources from the outside studio comes first here and enroots transmission to different destination like transmitter & earth station. This room comprises of: Routine Switcher, Stab amplifier, Video / Audio distribution amplifier, Color Stabilization amplifier, Sync generator, Frame synchronizer, Digital clock monitoring system, Logo generator, Vectro- scope, Waveform monitor, Video monitor, Hum Suppressor,
Video Equalizer, Change over unit. The CONTROL CONSOL PANEL consisting the control of Routine Switcher, Stab amplifier, Frame synchronizer & other MSR Equipments are stored here.
EARTH STATION
EARTH STATION is most significant part of Doordarshan
from communication point of view, as shown in figure:
Transmitting E/S Receiving
E/S
UPLINK
DOWNLINK
Digital Earth Station operates in frequency range 5.85
GHz to 6.425 GHz for transmission and 3.625 GHz to 4.24
GHz for reception of the signal.
Description of General Configuration of an Earth Station:
• Digital information in the form of binary digits when
enters earth station and is then processed (filtered,
multiplexed, formatted etc.) by the base band
equipment.
• The encoder performs error correction coding to
reduce the error rate, by introducing extra digits into
digital stream generated by the base band equipment.
• The function of the modulator is to accept the symbol
stream from the encoder and use it to modulate an
intermediate frequency (I.F) carrier.
In satellite communication, I.F carrier frequency is
chosen at 70 MHz for communication using a 36 MHz
transponder bandwidth.
• The modulated I.F carrier is fed to the up-converter
and frequency-translated to the uplink R.F frequency of
C-Band or Ku-Band as per desire.
• This modulated R.F carrier is then amplified by the
high power amplifier (HPA) to a suitable level for
transmission and radiation by the parabolic dish antenna
to the satellite. e.g.: Klystron amplifier, TWTA & SSPA.
• On the receive side, the earth station antenna
receives the low-level modulated R.F carrier in the
downlink frequency spectrum.
• The low noise amplifier (LNA)/ low noise block
convertor (LNBC) is used to amplify the weak received
signals and improve the signal to Noise ratio (SNR). The
error rate requirements can be met more easily.
• R.F is to be reconverted to I.F at 70 MHz because it is
easier design a demodulation to work at such
frequencies than in any of the GHz range.
• The demodulator estimate which of the possible
symbols was transmitted based on observation of the
received I.F carrier.
• The decoder performs a function opposite that of the
encoder. Because the sequence of symbols recovered by
the demodulator may contain errors, the decoder must
use the uniqueness of the redundant digits introduced by
the encoder to correct the errors and recover
information-bearing digits.
• The information stream is fed to the base-band
equipment for processing for delivery to the terrestrial
network.
• The downlink Beacon frequency is the concept, so
that tracking equipments track the satellite and align the
beam towards it to facilitate communication.
Fig. General configuration of an Earth Station
SATELLITE
COMMUNICATION
Satellite Communication plays a vital role in the global
telecommunication systems.
This technology was started in abroad in 1960, and in
India this was adopted in 1975.
Near about 2000 artificial satellites are orbiting Earth
relay analog & digital signals carrying voice, video and
data to & from one or many locations worldwide.
Satellite communication uses geostationary satellite and
operates in C & Ku band mostly.
First Indian National Satellite (INSAT) was launched in
1982.
Satellite Orbits: Types
Geostationary satellite:
A circular orbit 35,785 km (22,236 miles) above Earth’s Equator in which a satellite orbital period is equal to Earth’s rotation period of 23 hours and 56 minutes. A space craft in this orbit appears to an observer on Earth to be stationary in the sky. This particular orbit is used for meteorological and communications satellites. The geostationary orbit is a special case of geosynchro- nous orbit, which is any orbit with a period equal to Earth’s rotation.
Satellite Transmission Frequency Bands:
Frequency Band
• C-Band
• X-Band• Ku-Band
• Ka-Band
Uplink Frequency
• 6 GHz
• 8 GHz• 14 GHz
• 30 GHz
Downlink Frequency
• 4 GHz
• 7 GHz• 11 GHz
• 20 GHz
Satellite in Use:
Orbit type: Geo-synchronous
Orbital location: 93.5° E
Presently Doordarshan is using a latest, powerful &
largest geosynchronous satellite of INSAT series with high
power Ku- Band transponders to uplink the DD direct +
signals launched by ISRO in the beginning of the year
2007.
Figure: Footprints of INSAT 4B
Communication Satellite Transponders:
A communication satellite transponder is the series of
interconnected units, which forms a channel between
transmitting and receiving antennas. It is mainly used to
transfer the received signal, after deriving the transmit
carrier frequency from received signal.
It’s block diagram presentation is as follows:
HPT PITAMPURA
Dr. B. R. Ambedkar T V Tower (20kw power)
Total height: 235mtrs=RCC: 165mtrs+Steel: 70mtrs.
H P T stands for High Power Transmitters, which is
basically used for terrestrial transmission.
It is noticeable that about 92% population in India can
receive Doordarshan programs through the networks of
1415 terrestrial transmitters.
H P T Pitampura is started in Delhi on 7th Nov. 1988 by
Hon’ble Sh. Rajiv Gandhi the Prime Minister of India.
Total Area: = Covered Area: + Open Area:
16.155sqmtrs. = 2.105sqmtrs. + 14.050sqmtrs.
Coverage Area is about 85km radius in NCR as shown:
There is certain excellent information regarding:
TRANSMITTERS
DD NATIONAL DD NEWS
Channel no CH#5 CH#7
Power of Transmitter
20 KW 20 KW
Frequency of Vision Carrier
175.25 MHZ 189.25 MHZ
Frequency of Aural Carrier
180.75 MHZ 194.75 MHZ
EARTH STATION
DOWNLINK PARAMETERS
FREQUENCY : 3925 MHz
POLARISATION : HORIZONTAL FEC : 3/4
SYMBOL RATE : 27.5MSPS
BAND WIDTH : 36 MHz
O B VAN
Outside Broadcasting (OB) VAN is the electronic
field production i.e. EFP of television or radio
programs (typically to cover television news and
sports television events) from a mobile remote
broadcast television studio.
OB VAN is nothing but a mobile Production Control
Room (PCR) which is also known as production
truck/scanner/mobile unit/remote truck /live truck.
Interior
A typical OB VAN is usually divided into 5 parts:
1. Video Production Area:
This is the first & largest part of OB VAN, where video
production takes place. Video Switcher operated by
Technical Director and Video Monitors (showing various
video feeds) operated by TV Directors & TV Producers
are the main parts of this area. Figure:
2. Audio Production Area:
This is the second part of OB VAN, where audio
production takes place. Here Audio Mixers (being fed
with various audio feeds: reporters, commentary, on-
field microphones) are operated by Audio Engineers.
3. Video Tape Recording Area:
The third part of OB VAN is VTR area, which is nothing
but the collection of video server, house addition power
supplies or computers equipments. Here the EVS (LSM)
operators having one or more cameras that go into their
machines & can be played back in slow motion/pause
to show a key part of action during the game , and can
also play the replay rollouts that lead into commercial
breaks or show the highlights at the end of play.
4. Video Control Area:
The fourth part of OB VAN is Video Control Area
,where the professional video cameras are controlled
using “ Camera Control Unit” i.e. CCU by one or two
operators, to make sure that the iris is at the correct
exposure and that all the camera look at the same.
They can shade, balance, and focus the cameras from
this position inside the truck.
5. Transmission Area:
The fifth part of OB VAN is Transmission Area, where
the signal is monitored by engineers( to ensure the
people at the home have a good picture and a good
quality signal). Further this signal is transmitted or sent
to other trucks.
LAYOUT OF OB VAN:
DSNG
D S N G ie Digital Signal News Gathering is a system that
combines two technologies namely E N G ie Electronic
News Gathering with S N G ie Satellite News Gathering.
E N G is a broadcast news industry description of T V
producers,reporters & editors; making use of electronic
video & audio technologies for gathering & presenting
the news. It is less frequently used now because this
technology has become less ubiquitous.
S N G is the use of mobile communications equipment
for the purpose of worldwide news casting. Mobile units
are usually vans equipped with advanced, two way video
& audio transmitters & receivers, using dish antennas
that can be aimed at geostationary satellites. The earliest
SNG equipment used analog modulations eg: extensively
used in desert shield & desert storm operation in Persian
Gulf. But durring 1980, digital modulation supplanted the
analog modulation; giving rise to the newer technology
called D S N G.
The modern D S N G is a sophesticated affair , capable of
deployment practically anywhere in the civilized world.
The signals are beamed between a geostationary satellite
& van, and between satellite & control room bybroadcast
station or network. In most advanced systems Inter -
national Protocol(IP) is used.
Basically ,it is used for uplink of the gathered news
signals.Digital modulation tecnique applied here saves
the bandwidth.
Let us see the curbside view of D S N G van:
DD ARCHIVES
DD ARCHIVES is located at AKASHVANI BHAVAN,
Parliament Street, New Delhi.
This place is the treasure house of many memorable
performances of the great artists, who have contributed
to India’s rich music and dance heritage. This is amazing
endeavor done to bring some of exquisite performances
of enduring beauty to reach out the larger audience
celebrating the spirit of singing and dancing nation.
This section is equipped with following features:
1. Tape cleaning equipments for different formats.
2. Multi format preview suits.
3. Multi format debugging suits (with facility of Grass
Valley High Quality Noise Reduction System.)
4. Snell Wilcox High Quality Digital Restoration
Archangel Ph-C System.
5. DPS Velocity & Adobe Premier Pro Non Linear
Editing System (with facility of Diamond for video
restoration & Audition for audio restoration.)
6. Different Graphics Systems.
7. DVD burning equipments.
8. Tape Library Metadata System.
9. Different format tape libraries with compactors.
10. Media Asset Management System.
WHAT ACTUALLY DD ARCHIVES DOES???
1. To take the Old tapes from library
2. Cleaning of tapes as per their legacy formats
AMPEX (1972): manual cleaning
Umatic (1982): cleaned by RTI cleaner
BCN (1982): cleaned by RTI cleaner
Beta (1985): cleaned by RTI cleaner
DVC (modern): cleaned by RTI cleaner
3. Preview operation
4. Debugging operation
5. Restoration through DVC Pro 50:
Either in Archangel Ph-C System
Or in Puritan System
6. Restored output is fed to:
Server purpose
Commercial purpose
To keep in library
ESSENCE Different Possible Pathway for the :
TRANSMISSION Upto SATELLITE
1. TV Studio + PCR + TCR + MSR >> Transmitting E/S
>> Satellite:
2. OB Van + DSNG Van >> Satellite:
RECEPTION Upto HOME
1. : Receiving E/S + Terestrial Transmitters >> Yagi-
Uda Antenna + TV Screen.
2. : Reception by private dish + TV Scree.
3. : Reception by cable operator Receiver >> Cable
TV Network >> TV Screen.
SATYAM SHIVAM SUNDARAM
DOORDARSHAN KENDRA DELHI
THE END
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