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DTV standards broadcasters are going for: as the trek towards digital continues, broadcasters in the Asia-Pacific region and beyond are making their DTV standards choices known. Shawn Liew finds out more.

"You have a row of dominos set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly," Dwight D Eisenhower, 34th president of the United States, said at a 7 April 1954 news conference when referring to communism in the then Indochina region.

For the broadcast industry, the domino effect can certainly be used to describe the 'fall' of analogue broad-casting. Since Luxembourg became the first country in the world to complete the move to digital broadcasting in September 2006, more and more countries have followed suit, calling time on analogue.

Today, as the world stands on the cusp of a complete analogue switch-off, the Digital Video Broad-casting (DVB) Project, an international industry-led consortium of around 250 broadcasters, software developers, regulatory bodies and others in over 35 countries which develops a suite of internationally accepted open standards for DTV, has emerged as the pre-eminent technical standard for many digital video broadcasts around the world, including the DVB-T standard for digital terrestrial TV (DTT).

According to the DVB Project, 68 countries have already deployed DVB-T2 services and 59 more have adopted the standard, with the proliferation of worldwide analogue switch-offs generating an impetus to create a more spectrum-efficient and updated format.

In March last year, DVB's second-generation digital terrestrial standard, DVB-T2, which offer "an increased efficiency of 30%-50% in its use of spectrum compared to DVB-T, made its first commercial bow with the launch of the UK's Freeview HD service. Manufacturers have been quick to jump on the DVB-T2 bandwagon.

As an "active member of the DVB-T2 SD activity", TeamCast, a provider of digital modulation technologies for DTT, mobile TV and satellite transmission, recently released a new software version for its DVB-T2 modulator, the Power4-T2. Already available world-wide, the S130 software provides the capability to support multi-service layered modulation (multi-PLP), allowing the processing of eight parallel PLP inputs. Combined with the ability to perform SFN MISO (multiple inputs, single output) transmissions in full compliance with the DVB-T2 standard, it offers a strong leverage for DTT broadcasters willing to operate emerging DVB-T2 networks, says TeamCast.

Emily Dubs, product manager at TeamCast, elaborates: "This new release has been designed to meet DVB-T2 early adopters' expectations to evaluate the performance of this second-generation standard for DTT even in the most demanding conditions. The implementation of multi-service layered modulation and SFN-MISO bring key benefits to our customers and confirms TeamCast's leading position in DVB-T2."

In collaboration with Media Broadcast, Germany's national DTT operator, TeamCast provided the Power4-T2, equipped with the new S130 software, to support the DVB-T2 trial which took place late last year in northern Germany.

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During the trial, Media Broad-cast deployed a DVB-T2 network to measure the performance of the second-generation standard for DTT, including, in particular, multi-service modulation and SFN-MISO.

Stefan Krueger, head of Broad-cast Platforms and Services at Media Broadcast, reveals: "Using multi-service layered modulation enables us to measure the most demanding conditions such as urban and rural environments as well as cases like rotated and un-rotated constellations in parallel. TeamCast is a partner who enables us to go even further in this trial, in terms of the extensive testing that we require for DVB-T2 parameter selection."

While DVB-T2 may yet require time to gain traction in Asia, DVB notes that "more and more countries are considering DVB-T2 services for the near future", with Singapore, Malaysia and Thailand "seriously considering DVB-T2", while India and Sri Lanka have already adopted DVB-T2. At last year's BroadcastAsia show held in Singapore, DVB also demonstrated a live transmission of a DVB-T2 signal, then Asia's "first-ever Live DVB-T2 broadcast", even as the region's nations continue to mull over their choice of DTT transmission systems.

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Elsewhere in Asia, standards out-side the DVB family prevail. In China, prevalent standards include CMMB (China Mobile Multimedia Broadcasting), a mobile TV and multimedia standard developed and specified in China by the State Administrative of Radio, Film and Television (SARFT), as well as DTMB (digital terrestrial multi-media broadcast), the TV standard for mobile and fixed terminals used in China, Hong Kong and Macau.

In June 2009, TeamCast and its Chinese partner Digital Horizon successfully passed some intensive testing of their integrated CMMB offering at the SARFT laboratories in China. According to TeamCast, the objective was not only to illustrate modulators running in SFN (single frequency network) mode but also to highlight the product's robustness against loss of synchronisation reference signal and to prove the stability performance of its algorithm. Additional interoperability tests between different modulators as well as with various re-multiplexers were also successfully performed.

2008 saw the start of the CMMB network roll-out in China, with 30 cities covered initially.

After large-scale pilot testing during the Olympic Games period, CMMB networks are now deployed for full commercial operation across China. TeamCast's CMMB technology was used in the pilot networks deployed for the Olympic Games and is now ready for the commercial phase, through two main products, the MMB-2000 CMMB modulator and the new dual standard MCX-2000 modulator, ready for both DTMB and CMMB operation.

The product range launched by TeamCast to address the CMMB market is now ready for SFN action. "This product was introduced in its first release in November 2008, and this new software upgrade that brings top-level operating performance for SFN has been successfully qualified by SARFT," says Eric Pinson, product line manager at TeamCast. "With our local Chinese partner, Digital Horizon, we are ready to support Chinese broadcasters, by providing the highest performance technologies and by sharing our practical experience of deploying SFN networks."

In June last year, the Philippines became one of the first in the Asia-Pacific region to adopt the ISDB-T standard for its digital terrestrial TV. ISDB-T is the Japanese technical standard for DTV broadcast and is already widely adopted in a host of Latin American countries, including rising South American economic powerhouse Brazil, one of the first nations to adopt the Japanese standard.

Rohde & Schwarz, a supplier of solutions in the fields of test and measurement, broadcasting, radiomonitoring and radiolocation, as well as secure communications, recently released an enhanced version of the R&S SCx8000 low- to medium-power transmitter that includes ISDB-T capabilities.

Able to be switched seamlessly from analogue to DTV, the R&S SCx8000 contains seven height units in the UHF band and is able to achieve an output power of 600W in the coded orthogonal frequency division multiplex (COFDM) modulation mode.

Other products in Rohde & Schwarz's transmitter portfolio for setting up ISDB-T networks include the R&S NV8600 and R&S NW8500 high-power transmitters as well as the R&S NV8300 and R&S NW8200 medium-power transmitters, which cover the UHF and VHF bands, respectively.

Meanwhile, its R&S DVMS4 compact monitoring instrument, which was made available in November last year, monitors transport streams and DVB-T/H and DVB-S/S2 signals to ensure high operational capability. Able to simultaneously monitor the RF and transport stream characteristics of up to four signals, the R&S DVMS4 is ideal for sites with multiple transmitters, states Rohde & Schwarz.

In addition, its flexible hardware concept makes the R&S DVMS4 just as capable of monitoring tasks in DVB-T2 networks.

As broadcasters look to complete a smooth transition into the digital age, Rohde & Schwarz products are well suited to support any transition because they are multi-standard capable and can be completely updated and upgraded via multiple software options, a Rohde & Schwarz spokes-person reveals to APB.

In Europe, there is little doubt that the DVB standard is the dominant choice as the digital transition gains added momentum.

Teracom, a terrestrial broadcast service company owned by the Swedish government, recently chose Thomson Video Networks to supply headend technology for Sweden's continued roll-out of DVB-T2. Already available to 70% of the country's population, DVB-T2 is scheduled to cover the entire nation by the end of next year.

For the latest phase, Thomson Video Networks provided video headend solutions for Teracom, comprising its ViBE EM3000 and ViBE EM2000 encoders, NetProcessor 9030 multiplexers, and the XMS management system to enable the provision of HD services over the network.

The Thomson ViBE EM3000 HD MPEG-2/4 AVC encoders, when combined with the Flextream statistical multiplexing solution, the highly integrated and powerful NetProcessor 9030, and the fault- tolerant XMS management system, allow the complete Thomson system to deliver "unprecedented quality with efficiency and the highest levels of service availability", notes Thomson.

Peter Johnson, head of sourcing at Teracom Group, agrees: "This is a very important phase in the development of Sweden's broadcasting infrastructure ... Thomson Video Networks' expertise and market-leading compression technology are making a vital contribution to the successful roll-out of DVB-T2 in Sweden."

For German-based 2wcom, a global supplier of professional broadcast products, the development of a sophisticated and flexible DVB-T monitoring receiver to monitor the transmission of digital systems was a top priority, spawning the creation of the 2wcom FlexMon DVB-T monitoring system.

The FlexMon DVB-T performs a va- riety of activities, which include monitoring of the MPEG transport stream, validating the timing information of the mega-frame initialising packets (MIP), as well as monitoring the SFN performance and verifying the GPS reference.

According to 2wcom, the FlexMon DVB-T is designed to keep an eye on digital systems and alert users whenever processes are starting to run out of limits so that immediate corrective action can be taken to ensure continued coverage in the broadcasting area.

Ove Kamentz, head of Engineering at 2wcom, adds: "Together with the user-friendly operation concept and a clearly arranged menu navigation, the FlexMon DVB-T guarantees a comprehensive monitoring of your DVB-T network."

While digital technology continues to revolutionise the TV broadcast industry, debate continues as to which of the available DTT transmission systems should be adopted and deployed. The considerations for choosing any transmission system can only be judged on a case-by-case basis, dependent on the actual ASO (analogue switch-off) dates for individual nations, as well as the services to be offered, for example, 3D TV services would command high data rate requirements. In addition, the final decision is more often than not governed by political considerations.

Still, broadcasters can take heart from the fact that regardless of the transmission system that is eventually chosen by their host nation, solutions are aplenty to ensure that their transition to the digital age will be a smooth one.

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Author:Liew, Shawn
Publication:APB Magazine
Geographic Code:90ASI
Date:Mar 1, 2011
Words:1732
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