DVB-T2 – A Brief Overview and Comparison with DVB-T BES New … II... · 2017-08-27 · key...

DVB-T2 – A Brief Overview and Comparison with DVB-T

BESNew Delhi, India

J 2010January 2010

Martyn J HorspoolTelevision Transmission

Product ManagerHarris Corporation

USAUSA

DVB-T2 Briefing 1 assuredcommunications™ 11-Mar-10

Digital Terrestrial Transmission

• DTT activity around the World -– Many countries have already deployed DTT

• Analogue switch off in USA in 2009– Many countries are starting to deploy DTT

/– Most other countries are planning and/or evaluating DTT

• The unfortunate situation -• The unfortunate situation -– Just like analog, there are many different standards

for DTT

DVB-T2 Briefing 2 assuredcommunications™

Worldwide Digital Television Standards

CMMB/CTTBCMMB/CTTBISDB-T / ISDB-Tb


Worldwide Digital Television Standards

• Multiple Digital Standards exist for TV:– DVB-T / H– ATSC / ATSC M/H (Mobile Handheld)– ISDB-T / ISDB-Tb– CMMB– CMMB – CTTB– MediaFLO (Qualcomm, USA)– DVB-T2– DMB-T

• Equipment design must be flexible to allow any• Equipment design must be flexible to allow any standard to be used and a migration path to future standards


DTT Transmission

• Challenges for transmission equipment designers:– Multiple worldwide standards– New and emerging standards– Avoiding obsolescence– Analog-to-digital conversion should be easy– Analog-to-digital conversion should be easy

• Other Factors:– Efficiency / cost of operation– Meeting global regulations

• Compliance & standards, staying “green” (avoiding hazardous materials)hazardous materials)

– Applying new technologies• New RF devices, updated control systems, etc…



Brief Overview of DVB-T2

DVB-T2 Prototype Exciter (courtesy BBC)


DVB-T2 Basics

• DVB-T2 standard released (ETSI: EN302 755)• DVB-T2 is a digital terrestrial transmission system g y

developed by the DVB Project. • Introduces the latest modulation and coding

ff ftechniques to enable highly efficient use of valuable terrestrial spectrum for the delivery of audio, video and data services to fixed portable and mobileand data services to fixed, portable and mobile devices

• DVB-T2 is not designed to replace DVB-T in the g pshort to medium term; rather the two standards will coexist in many markets for many years.


DVB-T2 Advantages

• Higher data rates available:– 30% to 40+% improvement

U t 40 2Mb/ i ti l t d t t d i UK– Up to 40.2Mb/s in a practical system demonstrated in UK• Improved robustness over DVB-T:

– Better coding techniques (LDPC & BCH) provide improved noise g q ( ) p pperformance over DVB-T

– Rotated Constellations (provides up to 5dB gain in difficult reception areas))

• Added 256-QAM mode• Enhanced SFN performance using Almouti coding

E h ifi i (PLP) i th t i i• Each specific service (PLP) in the same transmission system can be optimized individually

• Peak-to-Average ratio can be reduced


Rotated Constellations (1)

• Map data onto a normal QAM (x,y)Rotate constellation (a es• Rotate constellation (axes now u1,u2)

• Ensure u1 and u2 travel in different cells

– So that they fade independentlyindependently

– Gather together in receiver

• Each of u1,u2 carries all of the info of original x,y

– So can decode (less ruggedly) if one is erased completely


Courtesy – Nick Wells, BBC Research

Rotated Constellations (2)


Courtesy – Nick Wells, BBC Research

Physical Layer Pipes - PLP’s

• Each data stream of the services to bethe services to be transmitted can be assigned it’s own PLPPLP

• Each PLP can be given its own user-

ifispecific error protection & its own level of security. In DVB-T2, up to 256 PLP’s can be assigned.


Extended Bandwidth Mode

• Out of Band spectrum falls away more quickly for 32k mode compared to 2k mode

– Allows 2% gain in capacity while staying within normal spectrumAllows 2% gain in capacity while staying within normal spectrum mask


DVB-T & T2 Comparison

In addition the constellation rotation may be switched on or• In addition the constellation rotation may be switched on or off

• Total DVB-T2 Modes = 8,064 plus other options such as number of PLP’s, SFN, etc.


Example of UK DVB-T2 Parameters


DVB-T2 Status Worldwide

• Only country so far to actually begin service is the UK:– First transmissions started Dec 2009 from Crystal

PalaceAggressive target is to have 60% population coverage– Aggressive target is to have 60% population coverage by World Cup 2010 (June)

– Planning 4 HD services on single channel using g g gH.264 compression

– Measured up to 40.2Mb/s bit rates– Actual coverage so far is much better than predicted


Receiver Availability

• Available T2 Set-Top Boxes:– Pace (Available early 2010)– Samsung– 3View (Available March 2010)

3View

– Humax (Available early 2010)– Dektec

Others will be available soon Humax Fox HD-T2– Others will be available soon• DVB-T2 Test equipment:

R&S (ETL)

Humax Fox HD T2

– R&S (ETL)– Teamcast– Dektec


From DVB.org web site

• What are the implications of DVB-T2 for countries planning to launch DVB-T services in the short to medium term?

A significant number of countries, in Europe, Southeast Asia, Africa, the Middle East and Latin America are planning for the launch of DVB-the Middle East and Latin America, are planning for the launch of DVB-T services in the next 2-3 years. These countries will benefit from the use of a mature technology that is flexible enough to meet their individual market requirements. In particular they will benefit from the existence of a well-established world market both for receivers and for head-end equipment. These conditions will enable the rapid roll-out and take up of DTT services in these countries, with access to cheap receivers being the key factor. The transition from analogue to digital services is what DVB-T is designed for.

In this timeframe it is neither feasible nor advisable to consider launching services with DVB-T2. The new standard is designed for a post-ASO environment, where DVB-T services are already well-established. Products that implement the DVB-T2 standard are not likely to become p ywidely available until 2010. Whilst prices will fall over time, in line with past experiences for DVB technologies, they can be expected to be relatively high initially. This means that DVB-T2 should not, in the short to medium term, be considered for the launch of free-to-air multichannel standard definition services targeted at migrating a general population from analogue


definition services targeted at migrating a general population from analogue to digital. DVB-T is ideal for these purposes.

The DVB-T2 Standard

ETSI EN 302 755 V1.1.1 (2009-09)European Standard (Telecommunications series)p ( )

Digital Video Broadcasting (DVB);g g ( )Frame structure channel coding and modulationfor a second generation digital terrestrialtelevision broadcasting system (DVB-T2)television broadcasting system (DVB T2)

Note:This document may be downloaded from:http://www.dvb.org/technology/dvbt2/


Final Comments

• Many DTT standards will co-exist in the World• Each country has its own specific requirements and

t t di f ltarget audiences, for example:– Fixed versus mobile reception– Standard definition vs HDStandard definition vs. HD– Free vs. pay TV– Availability & cost of receivers and STB’s

• Equipment manufacturers must be able to product equipment that can easily be updated at a later date for example:date, for example:– Migration from analog to digital– Migration from DVB-T to DVB-T2 in the future


Thank You !

Martyn J HorspoolTV Transmission Product Manager

Harris CorporationBroadcast Communications Division

www harris [email protected]


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