introduction to digital broadcast

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Introduction to Digital Video Broadcast...... Adrian Hornsby Broadcast Multimedia 10/29/08

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Lectures from Broadcast Multimedia course held at TUT

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Page 1: Introduction to Digital Broadcast

Introduction to Digital Video Broadcast......

Adrian Hornsby

Broadcast Multimedia

10/29/08

Page 2: Introduction to Digital Broadcast

Broadcast communications …

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Page 3: Introduction to Digital Broadcast

Broadcast communications …

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Page 4: Introduction to Digital Broadcast

Broadcast communications …

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Great fire New York - 1835Great fire New York - 1835

Page 5: Introduction to Digital Broadcast

Broadcast communications … and authentication mechanism

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Page 6: Introduction to Digital Broadcast

Morse signal communication…

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• Morse-Vail Telegraph Key, 1844-1845

• Vail helped Morse develop a practical system for sending and receiving coded electrical signals over a wire, which was successfully demonstrated in 1844.

• Morse-Vail Telegraph Key, 1844-1845

• Vail helped Morse develop a practical system for sending and receiving coded electrical signals over a wire, which was successfully demonstrated in 1844.

Page 7: Introduction to Digital Broadcast

Voice communication …

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In 1876, Alexander Graham Bell

"Mr. Watson. Come here! I want you!"

In 1876, Alexander Graham Bell

"Mr. Watson. Come here! I want you!"

Page 8: Introduction to Digital Broadcast

Radio …

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• 1860s, Scottish physicist, James Clerk Maxwell predicted the existence of radio waves

• 1886, German physicist, Heinrich Rudolph Hertz demonstrated that rapid variations of electric current could be projected into space in the form of radio waves.

• 1895 ,Guglielmo Marconi, Italian inventor, sent and received his first radio signal, in 1899 across the English Channel and two years later received the letter "S", from England to Newfoundland.

• Nikola Tesla and Nathan Stufflefield took out patents for wireless radio transmitters. Nikola Tesla is now credited with being the first person to patent radio technology; the Supreme Court overturned Marconi's patent in 1943 in favor of Tesla.

• 1860s, Scottish physicist, James Clerk Maxwell predicted the existence of radio waves

• 1886, German physicist, Heinrich Rudolph Hertz demonstrated that rapid variations of electric current could be projected into space in the form of radio waves.

• 1895 ,Guglielmo Marconi, Italian inventor, sent and received his first radio signal, in 1899 across the English Channel and two years later received the letter "S", from England to Newfoundland.

• Nikola Tesla and Nathan Stufflefield took out patents for wireless radio transmitters. Nikola Tesla is now credited with being the first person to patent radio technology; the Supreme Court overturned Marconi's patent in 1943 in favor of Tesla.

Page 9: Introduction to Digital Broadcast

Television …

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• Television started in the 1920s as a Peepshow device. • one viewer , 30 lines, tiny vertical screens, • received in a large part of Europe via the 'short wave', also used for radio.

• Audio sound was a separate short wave radio broadcast.

• Television started in the 1920s as a Peepshow device. • one viewer , 30 lines, tiny vertical screens, • received in a large part of Europe via the 'short wave', also used for radio.

• Audio sound was a separate short wave radio broadcast.

Page 10: Introduction to Digital Broadcast

Transistors …

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• John Bardeen, Walter Brattain and William Shockley at Bell Labs in 1947

• First practical application a hearing aid in 1952• Nobel Prize in 1956.

• John Bardeen, Walter Brattain and William Shockley at Bell Labs in 1947

• First practical application a hearing aid in 1952• Nobel Prize in 1956.

2008, transistor made out of graphene, one atom thick and ten atoms across

2008, transistor made out of graphene, one atom thick and ten atoms across

Page 11: Introduction to Digital Broadcast

Pulse Code Modulation …• Pulse code modulation was first disclosed in a patent issued to Paul M. Rainey of

Western Electric in 1921. • Method to transmit facsimile information in coded form over a telegraph line

using an optical mechanical analog to digital converter.

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Page 12: Introduction to Digital Broadcast

Analog to Digital conversion

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Page 13: Introduction to Digital Broadcast

New transmission systems …

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The Sputnik program launched by the Soviet Union on October 4, 1957

The Russian word sputnik literally means "co-traveler", "traveling companion" or "satellite”

http://www.amsat.org/amsat/features/sounds/sputnk1b.wav

Page 14: Introduction to Digital Broadcast

Digital revolution … New transmission, storage systems

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August 17th, 1982, the first Compact Disk (ABBA's the Visitors) came off the assembly line; 200 billion followed it. J

August 17th, 1982, the first Compact Disk (ABBA's the Visitors) came off the assembly line; 200 billion followed it. J

Page 15: Introduction to Digital Broadcast

Digital revolution … New media devices

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• First digital camera prototype in 1975 by Kodak

• 100 line black and white image • recorded to a cassette tape• took 23 seconds to write.

• First digital camera prototype in 1975 by Kodak

• 100 line black and white image • recorded to a cassette tape• took 23 seconds to write.

Page 16: Introduction to Digital Broadcast

Digital revolution … New media devices

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Page 17: Introduction to Digital Broadcast

Digital Media Revolution …

• Huge increase in media content• Faster communications • New user experience• New consumer demand

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New digital devices + new digital transmission systems =

New digital transmission standard

Page 18: Introduction to Digital Broadcast

DVB was born …

• 1991, European Launching Group (ELG)

-> Overseeing the evolution of digital television and its distribution in Europe

• September 1993, ELG renamed to DVB and becomes the major driving force in digital TV developement in Europe

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Page 19: Introduction to Digital Broadcast

Digital Video BroadcastingSatellite

• DVB-S, first standard for digital transmission over satellite system in december 1993 - (EN 300 421)

• Original DVB forward error coding and modulation standard for satellite television

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Page 20: Introduction to Digital Broadcast

DVB-S in short …– data insterted fixed length MPEG2-TS forming the payload. – Stream modulated using single QPSK (Quadrature Phase Shift Keyring)

carrier modulation• QPSK: phase of the carrier wave is modulated to encode bits in each phase change.

Bits are mapped to phase changes rather than to an absolute transmitted phase.

– Additional tools for channel coding and error protection– Design for Standard Definition Television (SDT) services

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Initial state

Page 21: Introduction to Digital Broadcast

Digital Video BroadcastingCable

• March 1994, DVB publishes DVB-C, addressing cable distribution system - EN 300 429

• Transmission of MPEG-2 or MPEG-4 family digital A/V stream, using a QAM modulation with channel coding

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Page 22: Introduction to Digital Broadcast

DVB-C in short …

• DVB-C uses QAM• input stream is divided into groups of bits. • In 8QAM, each three bits of input, which provides eight values (0-7) changes the

phase and amplitude of the carrier to derive eight unique modulation states

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Page 23: Introduction to Digital Broadcast

Digital Video BroadcastingTerrestrial

• December 1995, DVB publish the DVB-T standards (EN 300 744)

• Transmission of compressed digital data (A/V) in MPEG-TS (transport stream), using OFDM modulation with concatenated channel coding (COFDM).

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Page 24: Introduction to Digital Broadcast

DVB-T in short …

• Satellite vs Terrestrial– Different environment, different propagation

• Multipaths effect

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Page 25: Introduction to Digital Broadcast

DVB-T in short …

• OFDM was born: A single stream of data is split into parallel streams each of which is coded and modulated on to a subcarrier

• Each sub-scarrier is modulated with conventional schemes (QAM, QPSK)

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Page 26: Introduction to Digital Broadcast

Analog vs Digital

• The success of DVB-T has led to the Analog Switch Off (ASO)

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AnalogDigital

Page 27: Introduction to Digital Broadcast

Personal portable devices …

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Page 28: Introduction to Digital Broadcast

Personal portable devices…

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Page 29: Introduction to Digital Broadcast

Mobile phones …

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Users worldwide

Page 30: Introduction to Digital Broadcast

Digital Video BroadcastingHandheld

• DVB-H (Digital Video Broadcasting - Handheld) was formally adopted as ETSI standard EN 302 304 in November 2004

• Aims to provide digital TV to mobile devices• Combines traditional television broadcast standards with elements

specific to handheld devices– mobility, smaller screens and antennas, indoor coverage and reliance on

battery power

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Page 31: Introduction to Digital Broadcast

Then came along High Definition TV …

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• Your new HDTV needs an HD feed• Most TV program still in standard definition• SD typically looks terrible on an HDTV

• Your new HDTV needs an HD feed• Most TV program still in standard definition• SD typically looks terrible on an HDTV

Page 32: Introduction to Digital Broadcast

DVB-S2 …• Developed in 2003 and ratified by ETSI (EN 302307) in March 2005• The development of DVB-S2 coincided with the introduction of HDTV and

H.264 (MPEG-4 AVC)• Transmission of one or more MPEG-2 A/V streams , using QPSK or 8PSK or

MAPSK (M-ary amplitude and phase shift keying) modulation with concatenated encoding.

• Changing encoding parameters in real time (VCM, Variable Coding and Modulation)

• ACM (Adaptive Coding and Modulation) which optimizes the transmission parameters for various users.

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Page 33: Introduction to Digital Broadcast

DVB-T2 (BBC-T2) …• OFDM modulation with a large number of sub-carriers (up to 256)• LDPC (Low Density Parity Check) coding combined with BCH (Bose-

Chaudhuri-Hocquengham) for error correction• options : number of carriers, guard interval sizes and pilot signals to

minimize the overheads for any channel. • New Rotated Constellations technique for additional robustness• Separate adjustment of each delivered service also allowing tailored

transmissions (decoding only a single program rather than a whole multiplex)

• Transmitter diversity method (Alamouti coding)• Future Extension Frames for compatible extensions

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Page 34: Introduction to Digital Broadcast

Other DVB standards …

• DVB-SH, Satellite services to Handheld devices (SH) below 3 GHz

• DVB-SI, Service information

• DVB-IPDC, Internet Protocol Datacasting

• DVB-IPTV, Framework for the Delivery of DVB-Services over IP-based Networks

• DVB-GSE, Generic Stream Encapsulation (GSE) Protocol

• Etc … http://www.dvb.org/technology/standards/index.xml

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Page 35: Introduction to Digital Broadcast

Life of a standard …

1 ) Commercial Module based on market needs. set of user requirements that outline the user functions, timescales and

price range.

2 ) A DVB specification developed in the Technical Module and its Working Groups.

technological implications examined and available technologies are explored.

3) The Steering Board gives final approval of the specification and offers it for standardization

• New CALL for Technology DVB-C2

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Page 36: Introduction to Digital Broadcast

Exercises …

[email protected]• Create a ’newnsimple’ broadcast idea

– Commercial requirements (studies, trend, idea …)

– Technical requirements (research new R&D and apply it to your idea, and bring back the references)

– Present and advertise it among students, and bring back the proof.– Class will be the final steering board that gives the decision

• Good Presentation + good report + class happy = pass

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