‘Hybrid’ Services Point Up ‘Flexibility’ of ATSC 3.0, Its Framers Say

"The notion of sending certain things over broadcast and other things over broadband that could mix, synchronize and so on is part of the design of this,” said Chernock, who chairs ATSC’s Technology Group 3, the umbrella committee that’s supervising ATSC 3.0 standards developments. “Multiple services” that beam content to “a very wide range of viewing devices” are what ATSC 3.0’s framers envision will be featured in the system, Chernock said. “We're now starting to talk about possibly more than one video [option] per service.” Options such as “multiview” and “multiscreen” are another “possibility,” as is the option of choosing among standard definition, HD and Ultra HD resolutions, he said. The system also will adapt easily to future innovations, including “8K later if it makes sense,” he said.

"Scalable,” “interoperable” and “adaptable” are some of the code words that describe “the general principles” behind ATSC 3.0, Chernock said. Though ATSC 3.0 won’t be backward-compatible with the existing system, “there may be pieces that are similar,” he said. “There may even be pieces that are the same. That’s where it makes sense. But we want to add performance improvements, additional functionality -- enough so it’s worth going to this system. One reminder, and it’s been said many times in different words: The whole idea of this is to provide the toolkit. The toolkit provides the tools for the broadcaster to implement whatever kinds of business they want.”

Business considerations have a background presence in the ATSC 3.0 standards-setting process, Chernock said. “Most of us are not doing this because this is a nice and interesting challenge. We're doing it because it has some business interests for our companies. Those considerations have to be kept in mind. They're not part of the standards development, but they're in the back of everybody’s minds as we do this. And the other thing that affects us is regulatory. That’s going to influence things. We have no control over it, but it happens. We've got to keep that in mind as well.”

An audience questioner asked Chernock if he was aware of any “chatter” that the FCC might mandate ATSC 3.0 “at some point” as part of the spectrum repacking process that will follow the incentive auction. “Thoughts have crossed people’s minds, but it’s not part of our direct work,” Chernock responded. “However, those are the kinds of things you have to keep in the back of your mind. What the FCC does is known by the FCC. We're sort of marching down the direction based on technology.”

For broadcasters, ATSC 3.0, though a non-backward-compatible system, is “worth doing” because the existing ATSC system is “showing its age,” and broadcasters need new ways to compete with other forms of content delivery, said Skip Pizzi, NAB senior director-new media technologies, who chairs the S31 group on ATSC 3.0 use cases and scenarios. Referring to “this idea of hybrid services,” broadcasters “are really the only ones who can leverage this potentially huge power of over-the-air, plus online, services together,” Pizzi said. “Hybrid’s a big, important part” of ATSC 3.0, “and not just to be able to deliver stuff online and compete with Netflix and things like that, but to have that online component be added to the on-the-air content,” Pizzi said. “Nobody but broadcasters can do that.”

"There’s no putting ice and sugar” on the problem of multipath interference, but ATSC 3.0 has technical tools “on the table” to address it, said Luke Fay, senior staff software systems engineer at Sony Electronics, who chairs ATSC’s “S32” specialist group that’s trying to standardize the next-gen system’s physical layer. “People are more and more mobile today, and despite the fact that Mr. Angry Customer can move out of downtown and get a signal, he still wants to get TV reception downtown,” Fay said.

ATSC 3.0 will use orthogonal frequency division multiplex modulation with “guard intervals” that will “easily remove the multipath effects,” Fay said. It also will sport strong “forward error correction” coding to “recover symbol errors,” he said. “We're targeting fixed devices with indoor TV antennas. We're also targeting mobile devices with very short antennas, so we have a lot of parameters to deal with.”

ATSC 3.0 will feature “extensibility to account for future technology improvements,” Fay said. “One of the messages we want to send out is, this is the starting point for ATSC 3.0. We want to signal something that can grow.” He recalled that the existing ATSC system was finalized at the FCC in 1995, but didn’t first get on the air until nearly a decade later. “Yet here we are in 2014, and it’s already old. How did that happen? NTSC was fine for 50 or 60 years, and all of a sudden, 10 years out, we've got a problem. So we need to be flexible on technology. It’s always advancing.”

As for those future advancements, “determining mechanisms for graceful and agile evolution are an integral part” of the ATSC 3.0 work, said Madeleine Noland, an LG consultant who chairs S34 on ATSC 3.0’s applications and presentation layer, which includes the system’s basic audio and video parameters. “When the next greatest codec comes out, we will be ready to make the transition,” she said. “Graceful” is the “equitable word” to describe adapting to technological improvements, she said. “How do we get there without disrupting everything? That’s absolutely on the table, and part of the work.”

It was at last month’s NAB Show that Noland caused a minor stir, when she announced in her prepared presentation at the Broadcast Engineering Conference that 8K resolution likely wouldn’t be in the cards for ATSC 3.0. Moments later, she corrected herself to say 4K resolution would be ATSC 3.0’s starting point, and that the standard easily could be adapted for 8K later. In her presentation Wednesday, Noland appeared to have learned from her NAB Show gaffe when she beckoned those in the conference audience who are interested in 8K to “wait for my last slide,” the one citing “graceful and agile evolution” to future enhancements.