tv system and transmission mohit

8/11/2019 TV System and Transmission Mohit

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TV System and

Transmission

Prasar Bharti New Delhi

Mohit

B.Te


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Analog TV

Analog TV encodes television pictureand soundinformation and transmits analog signal.

Examples of analog television systems are:

NTSC

PAL

SECAM Broadcasters using analog television systems encode the signals using NTSC

SECAM encoding, and then modulate this encoded signal onto VHF or UHF

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Analog TV Standards by Regions3


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NTSC - National Television SystemCommittee

NTSC signal is an interlaced video signal with262.5 lines per field (525 scan lines per frame)

60 fields per second (30 frames per second)

4:3 aspect ratio

Out of these 525 scan lines

485 make up the visible raster (active lines)

The remaining 20 lines are blanked for vertical retraand synchronization.

Blanking pulses are inserted during the retraceintervals to blank out retrace lines on CRT and Syncpulses ensure that picture starts at the top left corne

of the receiving CRT.

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PAL - Phase Alternate Line

PAL is an analog television system used in mospart of western Europe, most part of Asia andother countries

It was developed in 1960s (in western Europe) overcome the weakness related to colourreproduction that existed in NTSC.

PAL is also interlaced like NTSC. Itconsists of625 lines per frame

50 fields per second (25 frames per second)

Both PAL and SECAM have better colorreproduction than NTSC.

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SECAM - SEquential Couleur AvMemoire

SEquential Couleur Avec Memoire is French for "Sequential CMemory

It is historically the first European color TV standard, develope1960s.

SECAM is also interlaced andconsists of

625 lines per frame

50 fields per second (25 frames per se

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Summary of the Analog TV Standards

fps lines Band-width

(MHz)

B&WMod.

ColourMod.

AudioMod.

NTSC 30 525 6 AM QAM FM

PAL 25 625 7-8 AM QAM FM

SECAM 25 625 7-8 AM FM FM

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TV TRANSMITTER TYPES

(A) VERY LOW POWER TX (VLPT)

TV TRANSMITTERS HAVING OUTPUT POWER10 W , 50 W.

(B) LOW POWER Tx (LPT)

TV TRANSMITTERS HAVING OUTPUT POWER LESS

THAN 1KW AND MORE THAN 50W .

( 100W , 300W , 500W )

(C) HIGH POWER Tx (HPT)

TV TRANSMITTERS HAVING OUTPUT POWER 1KW AND ABOVE .

( 01KW , 10KW , 20KW, 30KW )


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Digital TV Systems

Digital TV systems transmit audio and video by discrete signals (in c

signals in analog TV systems) Switching from analog to digital TV began in 2006 in Europe and a

countries have turned off their analog terrestrial broadcasting.

Two principle digital broadcasting systems are

ATSC (Advanced Television System Committee)

DVB (Digital Video Broadcasting

Other systems used are:

ISDB ( Integrated Services Digital Broadcasting)

DMB-T/H (Digital Multimedia Broadcasting)

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Digital terrestrial TV systems byregions

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DVB-Digital Video Broadcast

DVB-T

DVB terrestrial system uses coded OFDM(COFDM) which uses as many as 8000independent carriers each transmitting low rate.

It provides superior immunity to multipatinterference.

It has system variants that allow data ra4Mbit/s up to 24Mbit/s.

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New Broadcasting Technologies

HDTV and DTV

Mobile TV

IPTV

Digital Radio Emergency Broadcasting


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Digital radio - productions

The few radio stations in Asia trying tonews and production system digital.main features of the system are: Text Editing Audio Editing

Auto recording Wire Service Prompter for the news delivery Archiving


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Emergency Broadcasting

Radio and Television broadcasters are planning for more effewarning systems in the Asia-Pacific region by increasing the raccuracy of information flows from meteorological and disasmanagement organisations to broadcasters.

Earthquake

Seismograph

Earthquake Early Warningrelayed to public

0 5 10

Media organizations,Emergency services , etc .

MeteorologicalAgency

SecondlyW

ave

EarthquakeE

arly

Warning

Prima

ryWave

Computer generate Earthquake EarlyWarning upon detection P wave

Data

Time from Earthquake Early Warning until arrival of S-wa

Sec.1

Figure:Concept of Earthquake Early Warning


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TV Studio

A television studio is an installation in which video productio

either for the recording of live television to video tape, or for

of raw footage for post-production.

Studio hall is used for shooting various programs.

Artificial sets are created according to the requirement of pro

shooted.


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Overview of a TV Stud

Studio floorA studio floor has the following characteristics and in

decoration and/or sets

professional video camera (sometimes one, usualon pedestals

microphones

stage lighting rigs and the associated controlling e

several video monitors for visual feedback from thproduction control room (PCR)


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It is a room separated from Studio by a glass wall. This is the place where the

commands and control of studio

lies. The production director,

the technical director etc. sits there,

during the production.

This is the place where control

consoles of Production Switcher,

Audio Mixer, Control of Robotic

Camera, Talk Back, number of

displays, VTRs etc are kept.

PRODUCTION-CONTROL ROOM

Master Control Room (MCR)


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Master Control Room (MCR)

MCR is the finalpoint before a signal is

transmitted for broadcast.

MCR include banks of video monitors,

satellite receivers, videotape machines,

video servers, transmission equipment, and,

computer broadcast automation equipment

for recording and playback of television programm.

It also controls on-air signal. It may include controls to play back programs, swifeeds, satellite feeds and monitors the transmitter.


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Thankyou

tv system and transmission mohit

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