The Italian public broadcaster RAI will start broadcasting on Multiplex B in the DVB-T2 HEVC standard on August 28, according to Marco Rossignoli, president of Aeranti-Corallo, an Italian association representing around 150 local television broadcasters. 

In particular, Rai Storia, Rai Scuola and Rai Radio 2 Visual programs channels will be broadcast exclusively in this new standard. Within this mux, Rai 1 HD, Rai 2 HD and Rai 3 HD will also be broadcast in simulcast (in DVB-T2 HEVC) on channels 501, 502 and 503, the association said. 

The August 28th transition marks the first move towards DVB-T2 transmissions, which will provide increased bandwidth that could allow broadcasters to simulcast more channels. 

While many Italian TV sets are not capable of receiving DVB-T2, the final switchover is currently required to be completed by the end of the 2025. 

Rossignoli explained that "at this point, the transition to the new technology can no longer be postponed, in order to allow the local broadcaster to have adequate transmission capacity for broadcasting of its programs in high definition. To date, in fact, with the current DVB-T/MPEG-4 transmissions, the local television broadcaster has too little radio space to be able to transmit programs with adequate technical quality. We need to accelerate the transition of the entire Italian television system to the new standard."

MADRID, Spain—Spain’s RTVE has carried out what it says is the world’s first broadcast of an UHD 8K signal in DVB-T2.

The test was conducted in conjunction with University of Madrid, Cellnex, Dolby, Sapec, Sony, SGO and Samsung.

The display of the signal was carried out by Samsung, which prepared an adapted Samsung QLED 8K model for the test.

The text faced a number of challenges, including:

• Compressing the UHD-8K signal that represents more than 33 Gbps of video, in less than 33 Mbps, and maintaining the video quality that such a signal requires. This data gives a compression ratio higher than 1000:1. This challenge meant Sapec had to to perfectly adjust all the parameters that improve HEVC coding and optimize them to achieve it.
• Handle the huge amount of bits that a UHD-8K signal (48 Gbps) generates, since UHD-8K generates 50 images of 32 Mpixels (32 times more than the HD signal).
• The computing capacity was estimated to be greater than about six-times that necessary to encode UHD-4K.

The signal itself included new technologies such as:

• HDR with Hybrid Log-Gamma transfer function approved in the STD-B67 standard by the ARIB (Association of Radio Industries and Businesses).
• 50 frames per second frame rate.
• Extended color gamut, meeting recommendation of the ITU-R BT.2020, 10-bit depth and 4:2:0 subsampling.
• 5.1.4 multichannel audio.

In terms of compression, the text used HEVC for video coding, Dolby’s AC4 audio coding format and the DVB-T2 standard for the transmission of content.

The binary rate resulting from the audiovisual content was around 32 Mbps. The parameters of the COFDM modulation used for transmission via DVB-T2 from the UPM were: 32k extended, guard interval 1/128 and pilot pattern PP7.

The test also included a single PLP, with modulation of 64QAM and FEC of 5/6. With this configuration, a maximum binary rate of around 36 Mbps was reached, proving it to be a valid means to transmit the content without any issues. On the part of the UHD channel broadcast by Cellnex Telecom, the modulation parameters used for DVB-T2 transmission were: 32K Ext. 256QAM 2/3 GI 1/8 PP2 SISO. It is also a valid configuration to support bit rate requirements.

When the DVB-T2 standard was published in 2009, it was the first—and for awhile the only—second-generation Digital Terrestrial Television (DTT) standard. Because of its superior spectral efficiency and its operational flexibility, DVB-T2 has successfully been deployed around the world and is the technology of choice in many countries. Now, with ATSC 3.0 deployments underway, there is another second-generation DTT specification.

This article will explore the relevant differences between ATSC 3.0 and DVB-T2, starting with a comprehensive comparison of the physical and transport layers of each standard. Next, the article will evaluate the audio and video coding technologies that the systems support, noting the advantages of each approach with regards to equipment costs and licensing fees. With the growing popularity of smart and connected TVs and widespread broadband access, the article will conclude with a look at how ATSC 3.0 and DVB-T2 approach interactive service delivery and why the latter standard remains the strongest candidate for implementation of DTT services.

COMPARING THE PHYSICAL LAYERS

Only marginal differences for the spectral efficiency of a single channel exist between the physical layers of ATSC 3.0 and DVB-T2. The physical layer of ATSC 3.0 was built upon the same basic architecture as DVB-T2, which features OFDM and LDPC Forward Error Correction Codes. While ATSC 3.0 does include additional new tools such as non-uniform constellations and advanced LDPC codes, it only offers a slight improvement in performance that doesn’t outweigh the increased complexity.

There are additional new tools in ATSC 3.0, like MIMO (Multiple-Input and Multiple-Output) and LDM (Layer Division Multiplexing). DVB analysed the benefits of MIMO some years ago and made a deliberate decision not to include it in DVB-T2, owing to a lack of commercial demand for it. DTT operators expressed concern about the more complex and expensive network infrastructure its introduction would require. Furthermore, the introduction of MIMO forces the end user to install a new receive antenna.

LDM can provide spectral efficiency improvements for a limited choice of injection levels. The right mix of different injection levels is not always a typical use case and limits the use of LDM, which also adds complexity and cost to the receivers.

From a modulation perspective, ATSC 3.0 can operate up to 1024 and 4096 QAM, compared with DVB-T2 where the highest option is 256 QAM. The higher modulation scheme of ATSC 3.0 allows for more bits per symbol but it also introduces a higher signal-to-noise ratio, requiring a denser and thus more costly network. Currently, there is no market demand for constellations beyond 256 QAM in Europe. Indeed, the Recommended Practice for ATSC 3.0 television sets, issued by the CTA, mandates only constellations up to 256 QAM, indicating a similar market need in North America.

EXAMINING THE TRANSPORT LAYER

The transport layer of ATSC 3.0 moves away from MPEG2 Transport Stream (TS), which is well established in the industry. Instead it relies on an IP system based on the DASH Route and MMT specifications (Fig. 1). DVB, on the other hand, maintains that MPEG2-TS continues to be the best technical solution for unidirectional distribution of broadcast content, including terrestrial, satellite and cable.

By using MPEG2-TS, broadcasters can create a TS signal once and use it for a variety of different delivery platforms. Moreover, MPEG2-TS was developed specifically for broadcast. ATSC 3.0 relies on IP protocols, which may be advantageous in interactive use cases. Recognizing this, DVB, too, has several specifications intended for IP-based transport.

A LOOK AT AV CODING TECHNOLOGIES

For advanced video coding, ATSC 3.0 solely relies on HEVC, while DVB-T2 offers the flexibility to use HEVC or MPEG-4/H.264, lowering equipment cost thanks to minimal patent licensing fees. Both ATSC 3.0 and DVB-T2 allow broadcasters to deliver all video resolutions, from SD to UHD (4K), along with providing advanced features like High Dynamic Range, High Frame Rate, Wide Color Gamut and Next Generation Audio to enhance the viewers’ experience.

For subtitles, both ATSC and DVB use XML based solutions. DVB also has a widely implemented solution for bitmap-based subtitle delivery, which remains the preferred approach globally today.

CONTENT PROTECTION DIFFERENCES

Content protection is a key requirement today, especially for premium content like live sports and movies. A major difference between ATSC 3.0 and DVB-T2 is the method of content protection used. ATSC 3.0 relies on the MPEG Common Encryption (MPEG-CENC) scheme. It’s a perfect solution for delivering video protected by DRM over a broadband network to connected devices. The drawback: it is not specified for a broadcast-only environment, meaning most pay-TV use cases are left in the dark.

Conditional access (CA) is the heart of DVB-T2 content security, with support for Simulcrypt. This approach allows broadcasters to use different CA solutions. In addition, DVB also supports Multicrypt where all CA related functionality is implemented in one CA Module, separating the TV functions from the CA functionality. To make this approach work, DVB has specified the Common Interface (CI) between the TV set and the CA Module. This Interface is mandated in the European Union.

Overall the DVB CA approach is very successful; about 50% of all DVB receivers worldwide are used for pay TV.

INTERACTIVE SERVICE CAPABILITIES

According to Strategy Analytics, there are 1 billion connected TVs in homes globally. Given the nature of smart devices in use, today’s television viewers expect an interactive experience, with access to broadband and video content. Both ATSC and DVB-T2 (via HbbTV) support interactive service delivery. The major difference is that HbbTV has been established across Europe and other parts of the world, whereas ATSC 3.0 is still rather new. While trials are underway, it does not yet have an ecosystem for interactive applications and services.

In today’s connected world, interoperability is important. HbbTV provides a test suite so that devices, and suppliers of hardware and software components, can confirm compliance with HbbTV specifications. Having a test suite is an absolute must for delivering compliant and interoperable solutions.

CONCLUSION

ATSC 3.0 and DVB-T2 are both state-of-the-art digital television systems with advanced features like interactivity. The main technical differences lie in the transport mechanisms (IP for ATSC 3.0 vs. MPEG2-TS for DVB-T2) and content protection schemes (MPEG-CENC for ATSC 3.0 and CA/Simulcrypt/Multicrypt for DVB-T2) used. Ultimately, DVB-T2 has successfully been deployed by multiple countries across Europe, serving a combined population of more than 3.5 billion, meaning it has an established and proven ecosystem. Moreover, DVB-T2 is closely aligned with the wider set of DVB standards, supporting satellite, cable, IP and terrestrial delivery, whereas ATSC 3.0 only covers terrestrial use cases, limiting its appeal for those looking to implement digital television services.

Peter Siebert is the head of technology at DVB.

For a comprehensive source of TV Technology’s ATSC 3.0 coverage, see ourATSC3 silo.

NEW DELHI—ENENSYS/TeamCast and Comark are demonstrating a single platform that supports ATSC 3.0 and DVB-T2 at BES (Broadcast Engineering Society) Expo India, Jan. 17-19 at the Pragati Maidan exhibition and convention center.

The platform, which uses Comark’s Exact-V2 1RU exciter and ENENSYS’s release of a new TeamCast version of its ATSC Digital Exciter with support for 3.0 and DVB-T2 waveforms, gives broadcasters the opportunity to explore both standards.

“The support of both ATSC 3.0 and DVB-T2 waveforms on a single platform will enable broadcasters to experiment with both second generation standards with the maximum flexibility,” said Eric Pinson, terrestrial market manager at ENENSYS Group. “This also might motivate more innovation for new services in the future that would expand the maximum benefit of the different and complementary standards.”

In the view of Joe Turbolski, vice president of sales and marketing at Comark, having access to both standards will allow broadcasters to maintain their existing service while taking a closer look at the new opportunities made available by another standard.

“Adding this capability to our DTV exciter not only allows broadcasters to now deploy DVB-T2, but also to be able to test ATSC 3.0 as necessary, preserving their investment,” he said.

See the demo at BES Expo India, booth #41.

More information is available on the Comark, ENENSYS and TeamCast websites.

MUNICH, Germany--Three major Australian broadcast organizations recently conducted trials of DVB-T2, the next-generation of the Digital Video Broadcasting terrestrial standard.

Rohde & Schwarz provided transmitters, repeaters and test equipment to ABC (Australia Broadcasting Corporation) and SBS. Free TV, an industry body representing Australia’s commercial broadcasters, also supported the trial.

The Rohde & Schwarz equipment includes: an R&S TLU9 50 W transmitter, an R&S ETL TV analyzer and an R&S BTC broadcast test center.

DVB-T2, which can support 4K delivery, is being considered as a replacement for the existing DVB-T TV standard for over-the-air television transmission. Nearly all Australian TV viewers rely on over-the-air television service.

"Terrestrial free-to-air television delivers its service to 99 percent of the population, and over 20 million Australians tune in every week," remarks Peter Lambourne, CEO of Broadcast Australia, owner/operator of a large transmission network.

"This trial has been an important part of ensuring that when the time is right, the terrestrial television platform will be ready for the next stage of its evolution and can deliver the best possible viewing experience."

SAN JOSE, CALIF.—Harmonic has teamed up with German IP broadcaster Dimetis to create a fully integrated field test system to accelerate the distribution of next-generation terrestrial TV services in Germany.

Harmonic ElectraX2 media processor

The test system is a combination of Harmonic’s Electra X2 media processor, ProStream 9100 high-density stream processor, DiviTrackIP statistical multiplexing technology, and NMX Digital Service Manager integrated with Dimetis’ BOSS BROADCAST Manager, providing migration to the DVB-T2 and HEVC video compression standards.

The transition to DVB-T2 improves spectrum efficiency, SD to HD service enhancement, superior video quality, Dolby Digital Plus/AAC audio support, and DVB subtitles. With HEVC, DVB-T2 enables broadcasters to deliver more services per channel.

Harmonic and Dimetis will demonstrate the DVB-T2 HEVC field test system at booths 1.B20 and 1.B30 during IBC 2015, which runs from Sept. 11-15 in Amsterdam.