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 03-063. Production Control Room 07-094. Transmission Control Room 10-125. Master Switching Room 13-146. Earth Station 15-197. Satellite Communication 20-248. HPT Pitampura 25-289. OB Van 29-3210. DSNG 33-3511. DD Archives 36-3812. 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 STATIONEARTH 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-BandX-BandKu-BandKa-Band

Uplink Frequency

6 GHz8 GHz14 GHz30 GHz

Downlink Frequency

4 GHz7 GHz11 GHz20 GHz

Satellite in Use:

Orbit type: Geo-synchronousOrbital 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 NEWSChannel no CH#5 CH#7Power 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