As we predicted the third generation ATSC version of DTT was a major talking point at NAB and featured in at least two separate demonstrations. This highlighted what we had also pointed out earlier, which was how ATSC has taken over from DVB as the driving force taking DTT into the IP and Ultra HD era.
Essentially ATSC 3.0 has incorporated the best bits of DVB T2 including the fundamental OFDM (Orthogonal Frequency Division Multiplexing) and added refinements that address the challenges facing broadcasting as it converges with IP. These come under the headings of capacity, flexibility and extensibility.
On the capacity front, key attributes wanted included ability to deploy multiple HD programs over a single RF channel and to carry Ultra HD services, which is problematical over DVB-T2 even with HEVC coding. Related to this was the need for even greater resilience against impairments to signal propagation over the air under varying atmospheric conditions.
Under flexibility there is a need to configure services for both fixed and mobile reception on the same RF channel, as well as the ability to trade-off capacity versus robustness to suit varying demands and use cases. Then for extensibility an important requirement not conceived for DVB-T2 was the ability to introduce new services targeted at next generation receivers within the same RF channel alongside existing services. The ATSC 3.0 bootstrap facility was developed, allowing new receivers to be introduced and benefit from emerging services while existing receivers can go on accessing legacy services without any change.
South Korea has become a cheerleader and source of innovation for ATSC 3.0 having originally flirted with DVB-T2 as well as the European HbbTV hybrid broadcast standard, which initially gained some traction beyond the continent. Samsung has been heavily involved identifying the additions needed to enable higher quality services within the increasingly confined spectrum available for DTT. LG has got stuck in and participated with Korea Broadcasting System (KBS) and Seoul Broadcasting System (SBS) at one of those two demos at NAB. KBS and SBS showed how over-the-air (OTA) ATSC 3.0 can deliver UHD pictures at the full 4K resolution on LG 65-inch 4K TVs equipped with early ATSC 3.0 demodulator/tuner chips.
According to SBS Technical Director Young-Soo Park, these set the stage for the launch in the country of terrestrial UHD TV commercial services in early 2017 ready for DTT 4K broadcasts of the 2018 Winter Olympic Games being held in South Korea.
LG was also involved in the other ATSC 3.0 demo at NAB with its subsidiary Zenith, which otherwise featured just US technology companies, including Digital Alert Systems, Dolby, GatesAir, Harmonic, and DTT transmission equipment maker Triveni Digital. This demonstrated live end-to-end ATSC 3.0 workflows for a range of the broadcast capabilities including 4K and high dynamic range (HDR). Multiple programs of live and pre-recorded streams were displayed in 4K resolution with HDR, delivered at a frame rate of 60 fps along with next generation audio using Dolby equipment.
PILOT, formerly NAB Labs, provided the live camera feed, transmitting content generated with a 4K camera and then encoded, encapsulated, packaged, and signaled using ROUTE/DASH and MPEG-DASH protocols. Prerecorded content for the demonstrations was supplied by Harmonic and other ecosystem partners.
Another first and sign of ATSC 3.0’s coming of age at NAB was the demonstration of emergency alert broadcasting by LG in partnership with Sinclair Broadcast Group. This used technology called AWARN, which expands the disaster alert information that can be transmitted and makes the service more robust, with waking up of connected devices and transmitting features like HTML pages and evacuation routes over the air. This first-ever broadcast of the technology was transmitted by Sinclair from Las Vegas’ Black Mountain on Channel 45, to the Las Vegas Convention Center.
This takes emergency broadcasting to a new level by combining robust single frequency network transmission with rich media alerts that can be sent to any connected device and not just TVs or OTA radios.