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1 September 2022

Frequency reuse to accelerate Brazil’s TV 3.0, ahead of regulatory wrath

By trying to be all things to all people, Faultline’s latest webinar blended ATSC 3.0 and SBTVD 3.0 technologies and strategies, resulting in a round-the-world whistlestop tour spanning four continents. Our journey starts here with Brazil’s hotly anticipated TV 3.0 system.

Serendipitously, it happens that three of our executive panelists had just returned from a trip to Sao Paulo, where we are told excitement is brewing, as the SBTVD Forum – advisor to the Brazilian government – enters the third and final phase of tests ahead of finalization of the new DTT standard in 2024 and switch-on in 2025.

The SBTVD Forum’s Luiz Fausto, who doubles as Technology and Regulatory Specialist at Brazilian broadcaster Globo, took to the Faultline stage to flesh out details of the ambitious hybrid TV transition project. Plenty of airtime was given to a critical component we have seldom covered, called reuse-1, which describes use of the same RF channel by independent stations covering adjacent service areas.

The ambition behind reuse-1 is that the SBTVD Forum did not want TV 3.0 to be bound by a black box with all components integrated and ready to use. It endeavored to source the best possible technologies available and fit these around its particular country-specific requirements, while doing certain things differently to elsewhere in the world. One example is in the case of applications, with the idea to eliminate the entire concept of channels.

Instead, every broadcaster will be an app. When you turn on your TV, it will scan for apps available OTA, instead of channels, and once you receive an app, it’s installed on your TV and is responsible for the presentation layer, Fausto explains. Viewers will be presented with content that comes OTA via FTA broadcast or over broadband, and it can switch between these seamlessly.

“Everyone in the world agrees on the need to enhance audio-visual quality, but on transmission technology for the physical layer for FTA broadcast, we wanted to do something different,” continues Fausto.

Frequency reuse-1 comes in by enabling segmentation of geographic coverage, allowing for the same 6 MHz channels in Brazil to be used by neighboring stations broadcasting different content. This would allow broadcasters to target smaller regional areas, in a more efficient and precise way, using dual location, as an IP address is not as precise and not as granular as you can get with OTA.

Broadcast will always be a more efficient way to deliver content to a large group of people at the same time, while broadband brings more personalization to viewing experiences. TV 3.0 – like ATSC 3.0 – wants the best of both worlds, which is why TV 3.0 has selected component technologies proposed by the ATSC.

Interestingly, we learn that of the seven technical proposals submitted by the ATSC to the SBTVD Forum, four were accepted. While the physical layer is an ongoing process – as arguably the most challenging technological area – we learn that one of the rejected proposals pertains to the exclusive use of HEVC, which the ATSC’s Skip Pizzi, Chair of IT-5 Brazil Implementation Team, admits was fully expected given that everyone was looking ahead to VVC.

This is also good news for UK-based compression company V-Nova, not only because its LCEVC technology has been selected by the SBTVD Forum to lower the complexity and enhance the quality of the VVC codec for TV 3.0, but also as an IP owner in VVC.

Pizzi is also fired up about reuse-1, despite not envisioning this kind of application with ATSC 3.0, whereby the physical layer lends itself to provide greater flexibility for the transmission network to enable OTA geo-targeted content. Frequency reuse-1 could get even more interesting should neighboring countries adopt the approach, as it would greatly simplify the international coordination of TV channels in border areas following the technological transition to TV 3.0.

Drawing comparisons from experience in the US market, Pizzi explains that in some parts of Brazil there is spectrum to do simulcast, whereas big cities – like Sao Paolo (22.4 million people) – are more like the US where spectrum is fully occupied.

Therefore, some kind of channel sharing option might be necessary, involving a hybrid transition model, and then applying reuse-1 on top, although Pizzi admits that makes things fairly complicated.

What we do know is that roll-outs of TV 3.0 will start in major cities, where spectrum is more congested and the conditions therefore more challenging – so some sort of channel sharing effort will be necessary to facilitate smooth deployments.

Lessons can be learned from Brazil’s digital switchover, which was not done in single shot, but on a region-by-region basis, where areas of low population density are still in the transition from analog where shared infrastructure is being used. Without shared infrastructure, it would not be economically feasible to reach these smaller cities, which has given Brazilian broadcasters a sense of opportunity around shared infrastructure and the efficiencies this can bring.

“This may help accelerate 3.0 and may even start off with shared infrastructure in the big cities,” notes Fausto.

There are other factors involved, such as specifying the receiver for TV 3.0 so that it seamlessly integrates existing DTT channels and TV 3.0 channels for end users. For example, during the analog to digital switchover, there were TV receivers that received both analog and digital signals, but were simulcasting most channels, meaning consumers received the same channel in both analog and digital with different channel numbers. Viewers therefore had to grapple with learning which number channels were analog and which number channels were digital, causing quite the headache, which is naturally something TV 3.0 wanted to avoid desperately with the new transition.

This analog-digital simulcast caused “absolute disruption” in terms of video quality, Fausto recalls.

So, when programs are available in the new TV 3.0 system, existing channels in the previous DTT system will be automatically disabled to more easily facilitate the transition. This ties back to scrapping the concept of channels and channel numbers, while creating what Fausto called “fake apps” for existing channels, to be integrated into the same UI.

“The existing DTT system in Brazil is very good. We have broadcast in HD since 2007 using H.264 at 40 Mbps, so it’s good quality video even with a large screen TV. But we need to think of more economically efficient ways of deploying the transmission stage to scale faster,” continues Fausto.

One factor supporting this effort is that all TV sets supporting Brazil’s terrestrial TV evolution are manufactured in Brazil, meaning the SBTVD Forum can work closely with receiver makers to accelerate adoption.

From technical details, we cross the treacherous bridge into timeframes and regulators.

Faultline presses Fausto on the inevitability of delays with TV 3.0, as seen with ATSC 3.0 in the US. His answer is an honest one about the difficulty in communicating timeframes due to the many variables involved in the TV 3.0 project undertaking – pointing specifically to the dreaded regulatory hurdles following technological finalization.

Broadcasting as a business is tightly regulated not just in Brazil but the world over. In order to allow a broadcaster to use a new TV system, it requires change at the regulatory level (as discussed in our separate piece this week on ATSC 3.0 delays in the US). “You cannot just transmit whatever you want. You need a different license, and generally that license doesn’t specify technology,” adds Fausto.

Delivering FTA content involves decoupling, with one company transmitting and another manufacturing the equipment to receive these transmissions, so there is a need for common standards in broadcasting – which could delay TV 3.0.

Another non-technological factor leading to potential delays is the SBTVD Forum’s reliance on public funding, which takes time to source.

Despite digging up uncertainties, Fausto highlighted, “We have the technology to be specified by 2024.”