Maarg Manthan · Topic 14.32

Digital Terrestrial Television Transmission System

Science & Technology › IT, Telecommunications and Computers · Topic 14.32

Digital terrestrial television, DTT, is the broadcasting of television signals in digital form from ground transmitters to rooftop or set-top antennas, without cable or satellite. Compared with old analogue broadcasting, digital transmission carries several channels in the same frequency slot, gives clearer pictures and sound, and frees spectrum called the digital dividend. The common standards are DVB-T2 in Europe, India and many other countries, ATSC in the United States and ISDB-T in Japan and Brazil. Prasar Bharati, through Doordarshan, runs the terrestrial network in India and the switch to digital DVB-T2 transmitters began in the 2010s. A newer idea called Direct-to-Mobile broadcasting, D2M, sends video straight to phones.

5 min read · UPSC Prelims · Science & Technology · IT, Telecommunications and Computers

At a Glance

Indian standard DVB-T2
Broadcaster Prasar Bharati and Doordarshan
Benefit Digital dividend
Other platforms DTH, cable, IPTV
New idea Direct-to-Mobile
Exam link UPSC Prelims, Science & Technology: IT, Telecommunications and Computers

Where Does It Fit?

This topic closes the macro. It links the spectrum and broadband topics to broadcasting, showing how television signals also use the radio spectrum and are moving from analogue to digital. Previous topic: Ransomware Threats (Locky, Petya, WannaCry). Next topic: Superconductivity: History, Classification and Applications.

What Is Digital Terrestrial Television and How Does It Work?

Aspect	Details
Meaning	Digital television broadcast by land-based transmitters, received through an antenna and a digital tuner or set-top box
Compression	Video is compressed with MPEG-2 or MPEG-4 and many programmes are combined in a multiplex
Modulation	DVB-T2 uses OFDM, which splits data across many carriers to resist interference
Standards	DVB-T2 (Europe, India, many countries), ATSC (United States), ISDB-T (Japan, Brazil), DTMB (China)
Benefits	Better picture, more channels per frequency, free or low cost reception, mobile reception and data services
Digital dividend	The spectrum released by switching off analogue television can be used for mobile broadband
Analogue switch-off	Many countries ended analogue broadcasts, while India completed the switch of analogue cable television in 2012 to 2017 and kept some analogue terrestrial transmitters

What Is the Indian Position and Other Platforms?

Prasar Bharati: the public broadcaster set up under the Prasar Bharati Act, 1990, which runs Doordarshan and All India Radio
Doordarshan terrestrial: a very large number of transmitters, with a growing number of digital transmitters using DVB-T2 for free to air channels
DTH: Direct to Home uses a small dish and a set-top box to receive signals from a satellite, and is a main platform in India
Free Dish: DD Free Dish is the free-to-air DTH service of Doordarshan, launched in 2004
Cable: digital addressable cable systems were made mandatory in phases from 2012 to 2017
IPTV: television over broadband internet protocol
TRAI role: regulates tariffs and quality of service for broadcasting and cable services
Direct-to-Mobile: broadcast of video straight to smartphones using spectrum, being tried in India with a pilot in cities in 2024. Check the latest status

What Else Should You Remember?

Analogue and digital: analogue signals vary continuously while digital signals use discrete bits
Set-top box: a device that converts digital signals for old televisions
Conditional access system: allows pay channels to be viewed only by subscribers
Digital Addressable System: lets operators control each subscriber’s connection
High definition and 4K: higher resolution pictures that need more bandwidth
MPEG-4 and H.265: compression methods that give better quality at lower data
Spectrum for television: terrestrial TV uses VHF and UHF bands, and the 700 MHz band was auctioned for mobile services
Digital dividend in India: the 700 MHz band, freed by the shift to digital, is useful for wide coverage mobile broadband but was not sold in some auctions because of high prices
Single frequency network: many transmitters on the same frequency to cover a region
Emergency alerts: broadcast networks can send warnings during disasters
Community broadcasting: radio stations run by local groups
Broadcasting Services Bill: a draft to update the law for digital and online broadcasting was debated in 2023 and 2024
OTT platforms: streaming services that compete with television
Link: radio spectrum management is in Spectrum Policy and Mobile Spectrum Management in India
Link to broadband: broadcast to phones is also related to Broadband Policy in India
Convergence: television, internet and mobile services are merging
Rural reach: terrestrial and DTH help where cable and broadband are weak
Antenna and reception: a simple rooftop antenna or a set-top box with a built-in tuner can receive free-to-air digital channels
Mobile TV: DVB-T2 Lite and similar standards were designed for reception on moving receivers
Local content: terrestrial networks carry regional and local channels that reach areas without cable
Digital switchover cost: broadcasters and viewers must pay for transmitters and set-top boxes, which slows the change

Why Does It Matter for the Exam?

Standards: DVB-T2 for India
Concepts: digital dividend, compression, multiplex
Institutions: Prasar Bharati, Doordarshan, TRAI
Current affairs link: Direct-to-Mobile and broadcasting bill
Common errors: confusing DTT with DTH or saying India uses ATSC

As an analytical point, digital terrestrial broadcasting saves spectrum and gives wide, free reach, especially in remote areas. Direct-to-Mobile may relieve mobile networks from heavy video traffic, but needs handset support and spectrum sharing.

Why Is This Topic Important?

Standard DVB-T2
Benefit Spectrum saved
Platforms DTH, cable

What Came Next?

The next macro covers materials science, nanotechnology and robotics. Next topic: Superconductivity: History, Classification and Applications.

Key People and Terms

DTT Digital terrestrial television
DVB-T2 Second generation terrestrial standard
Multiplex Many channels in one signal
Digital dividend Freed spectrum
DTH Direct to Home
D2M Direct-to-Mobile

Exam Corner

Points to Remember

India uses DVB-T2.
Prasar Bharati Act: 1990.
DD Free Dish: 2004.
Digital cable made mandatory in phases up to 2017.
DTT is ground based; DTH is satellite based.

Do Not Confuse With

DTT and DTH Ground transmitters versus satellite dish
Analogue and digital Continuous versus coded signals
Prasar Bharati and TRAI Broadcaster versus regulator

Memory Hook

Terrestrial is by tower, DTH by dish; DVB-T2 in India; the dividend feeds mobile.

Mains Angle

Questions ask for standards, institutions and differences. These points help.

Benefits Spectrum and quality
Platforms Convergence
Future D2M

A Question You May Face

An original practice question, not a past paper question.

“Discuss the advantages of digital terrestrial television and the prospects of Direct-to-Mobile broadcasting in India.”

How to Answer

Technology Digital broadcast.
Benefits Dividend.
India Platforms.
D2M Prospects.

GS Relevance

Prelims: DTT, DVB-T2, Prasar Bharati, digital dividend, DTH. GS Paper 3: IT and communications, broadcasting.

Frequently Asked Questions

What is digital terrestrial television?

Digital terrestrial television is a way of broadcasting television in digital form from ground-based transmitters to antennas on rooftops or in set-top boxes, without using cable or satellite. It carries several channels in one frequency slot, gives better quality and releases spectrum for other uses.

Which standard does India use for digital terrestrial television?

India has adopted the DVB-T2 standard, the second generation Digital Video Broadcasting terrestrial standard also used in Europe and many other countries. Doordarshan has been installing DVB-T2 transmitters, which use MPEG-4 compression to carry several channels in one multiplex.

What is the digital dividend?

The digital dividend is the radio spectrum that becomes free when television moves from analogue to digital broadcasting, because digital signals need less bandwidth. The freed bands, such as 700 MHz, can be used for mobile broadband, which is valuable because low frequencies give wide coverage.

What is the difference between DTT and DTH?

Digital terrestrial television reaches viewers from land-based transmitters through an antenna, while Direct to Home delivers channels from a satellite to a small dish and set-top box at the viewer's home. DD Free Dish is a free-to-air DTH service of Doordarshan.

What is Direct-to-Mobile broadcasting?

Direct-to-Mobile, D2M, broadcasting sends video and other content straight to smartphones using broadcast spectrum, without using mobile data. It could reduce the load on mobile networks and help in emergency alerts and education, but it needs chips in phones and agreement on the use of spectrum. Trials have been held in India.

PYQ Practice — Statement Analysis

1 India has adopted the DVB-T2 standard for digital terrestrial TV.

True

Used by Doordarshan.

2 DTH delivers signals through ground-based transmitters.

False

It uses a satellite.

3 Digital dividend means spectrum freed by analogue switch-off.