ATSC 3.0 and the Future of Broadcast Television: OTA Meets OTT
What’s unique about ATSC 3.0, at least as it bears on IP delivery, is that it becomes a form of multicast, that long-available but highly underused capability to send the same IP packets to every single device on a network without requiring unique bandwidth for each device.
In other words, it allows scaling viewership without the need to scale the infrastructure. It makes logical sense, because an analog television broadcast could be received by one device or hundreds of thousands of devices without requiring multiple towers, and the same was true with ATSC 1.0 and its digital transmission.
Yet all this time, multicasting of IP has been a feature that’s been not just overlooked, but has actually been derided as not practical.
That’s about to change, and the streaming industry might just get schooled on the benefits of an IP standard that’s been around for more than 30 years.
Having said that, the transition to ATSC 3.0 is not going to happen all at once. In fact, as TV Technology reported after the NAB show in New York in October, even those broadcasters announcing support aren’t likely to all roll out ATSC 3.0 in 2020.
“It doesn’t mean every station in these groups will be deploying the standard,” Tom Butts wrote in an October 2018 article, “but instead will collaborate with each other to provide a large enough national footprint so that a majority of American consumers will be able to receive some form of ATSC 3.0 service.”
What happened to ATSC 2.0, and why aren’t we transitioning to it rather than leapfrogging to ATSC 3.0? It turns out that the delay in the “analog sunset” threw timing off not just for ASTC 1.0—which was initially introduced in 1996 even though it didn’t come to fruition until 2009—but also for the next version.
The good news is that the transition from ATSC 1.0 towers (called “lighthouses” in industry terms) to ATSC 3.0 transmission may not create the pain point that the U.S. faced in the 2009 “analog sunset” era.
“The cost to upgrade to an ATSC 3.0 lighthouse is fairly small compared to the existing infrastructure that’s already in place,” said Anne Schelle, Pearl TV Group’s director, in the same TV Technology article. Her group is working with Univision and others to test ATSC 3.0 in Phoenix, testing first on one tower and then adding towers to look at how IP delivery might work in the domain of multiple competing towers and infrastructures.
What Do We Get for Our Troubles?
Maybe this section should be labeled “Is it worth the pain of moving from ATSC 1.0 to ATSC 3.0?”—but that’s a bit of a mouthful.
ATSC 1.0 was proposed in a time period where a 1280x720 progressive (720p) broadcast standard was considered achievable, and later extensions to the standard grew the overall transmission cap to 1080p. Given the limited frequency spectrum of each broadcaster’s tower, which is 19.2 MHz or roughly 19.2Mbps—the 1080p cap was a bit of a stretch, but still achievable, at least for content that didn’t exceed 30 frames per second.
The truth, though, is that even with the ability to transmit 1080p broadcasts from an ATSC 1.0 tower, the number of consumer televisions capable of demodulating a 1080p broadcast transmission is fairly slim. Yes, the TV itself can display 1080p but, thanks to ATSC 1.0-era tuners, the vast majority of consumer HDTVs max out at 1080i for OTA display.
With the ATSC 3.0 standard, the good news is that 1080p is the base level of transmission, and 4K (Ultra HD at 3840 x 2160 pixels) progressive is now part of the standard. If this modern transmission standard is extended, the possibility exists to offer 8K transmissions in the future, assuming of course that consumer electronics manufacturers offer 8K televisions with standards-compliant 8K tuner cards.
LG Electronics, along with Sony Electronics, is providing test TV units as well as test and measurement equipment such as demodulators—transmission units that receive a particular encapsulated signal that has been modulated for long-distance OTA transmission, unpacking the transmission back to a format that the consumer TV understands—for testing in various broadcast locations across the U.S.
In addition to the 4K UHD transmission sweet spot, ATSC 3.0 also offers enhanced imaging features found on a number of today’s OTT set-top boxes. The laundry list of acronyms includes high dynamic range (HDR), which is most often associated with 10-bit color depth delivery, at least from an OTT standpoint.
In addition, the availability of WCG means that OTA transmissions would support the Rec. 2020 specification, which practically brings OTA transmission to the same image quality as a select group of on-demand content offerings by Hulu and Netflix.
Audio has advanced in the OTT set-top box world—think Dolby’s HDR-centric Atmos, which also includes 7.1 surround sound enhancements—and the ATSC 3.0 standard follows suit, adding the ability to use Dolby AC-4 audio rather than the prior AC-3 that could only offer 5.1 surround functionality.
Finally, ATSC 3.0 also provides for high frame rate (HFR) transmission. Given the restricted nature of the overall transmission bandwidth, it’s possible that legacy H.264 content may only be able to be delivered at standard frame rates. But if consumer electronics manufacturers offer other codecs in their HDTVs, such as AV1 or H.265 (High Efficiency Video Coding or HEVC), the adoption of high-frame-rate transmissions could increase.
What about mobile devices? After all, anyone who calls the push by the NAB organization to get TV and radio tuner chipsets embedded in smart phones will likely also remember that this push was met with resistance from broadcasters, consumer electronics manufacturers, and consumers alike.
The good news is that ATSC 3.0’s ability to transmit in IP packets means that any device capable of decoding and demodulating ATSC 3.0 signals—whether in hardware or, eventually, in software as mobile processors increase in speed without impacting battery life—will be able to view these OTA broadcast transmissions. In the case of a mobile device without an ATSC 3.0 chipset, delivery appears to be via unicast streaming, so the question of scalability remains for legacy mobile handsets and tablets—at least until even mobile devices have ATSC 3.0 embedded chipsets.
The End Is Near
With all the enhancements to OTA broadcast, and the potential promise of finally being able to scale live-event streams on a global level, when can we expect to see all of this ATSC 3.0 goodness?
The first step, beyond OTA transmission tests, is for consumer electronics manufacturers to deliver HDTVs with ATSC 3.0 chipsets. So what’s the current status of ATSC 3.0-compliant consumer HDTV units?
LG Electronics already has launched HDTV units in Korea that have ATSC 3.0 chipsets but has not yet done so in the U.S. Sony and others are following suit, with anticipated availability of ATSC 3.0-based consumer HDTVs by 2020.
It’s also possible that we will see ATSC 3.0 HDTVs on display at the Consumer Electronics Show (CES) in Las Vegas in early January 2019 (this article was written in November 2018). But just like early 4K flat panels, which did not have all of the standards-based features for UHD playback, a note of caution should be sounded for those thinking of buying the first-generation ATSC 3.0-compliant displays.
Still, once we reach a point of critical mass for both consumer HDTVs and OTA broadcast groups, the ATSC 3.0 standard appears to hold significant promise in merging traditional OTA delivery with more recent OTT delivery. When it comes to live events, scaled to global television audience levels, it’s ironic that the streaming industry may be following the lead of the traditional broadcast industry it has tried so hard to displace over the past 20 years.
[This article appears in the January/February 2019 issue of Streaming Media Magazine as "ATSC 3.0 Live TV and the Future of Streaming."]
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