Video: ATSC 3.0 Seminar Part III

ATSC 3.0 is the US-developed set of transmission standards which is fully embracing IP technology both over the air and for internet-delivered content. This talk follows on from the previous two talks which looked at the physical and transmission layers. Here we’re seeing how IP throughout has benefits in terms of broadening choice and seamlessly moving from on-demand to live channels.

Richard Chernock is back as our Explainer in Chief for this session. He starts by explaining the driver for the all-IP adoption which focusses on the internet being the source of much media and data. The traditional ATSC 1.0 MPEG Transport Stream island worked well for digital broadcasting but has proven tricky to integrate, though not without some success if you consider HbbTV. Realistically, though, ATSC see that as a stepping stone to the inevitable use of IP everywhere and if we look at DVB-I from DVB Project, we see that the other side of the Atlantic also sees the advantages.

But seamlessly mixing together a broadcaster’s on-demand services with their linear channels is only benefit. Richard highlights multilingual markets where the two main languages can be transmitted (for the US, usually English and Spanish) but other languages can be made available via the internet. This is a win in both directions. With the lower popularity, the internet delivery costs are not overburdening and for the same reason they wouldn’t warrant being included on the main Tx.

Richard introduces ISO BMFF and MPEG DASH which are the foundational technologies for delivering video and audio over ATSC 3.0 and, to Richard’s point, any internet streaming services.

We get an overview of the protocol stack to see where they fit together. Richard explains both MPEG DASH and the ROUTE protocol which allows delivery of data using IP on uni-directional links based on FLUTE.

The use of MPEG DASH allows advertising to become more targeted for the broadcaster. Cable companies, Richard points out, have long been able to swap out an advert in a local area for another and increase their revenue. In recent years companies like Sky in the UK (now part of Comcast) have developed technologies like Adsmart which, even with MPEG TS satellite transmissions can receive internet-delivered targeted ads and play them over the top of the transmitted ads – even when the programme is replayed off disk. Any adopter of ATSC 3.0 can achieve the same which could be part of a business case to make the move.

Another part of the business case is that ATSC not only supports 4K, unlike ATSC 1.0, but also ‘better pixels’. ‘Better pixels’ has long been the way to remind people that TV isn’t just about resolution. ‘Better pixels’ includes ‘next generation audio’ (NGA), HDR, Wide Colour Gamut (WCG) and even higher frame rates. The choice of HEVC Main 10 Profile should allow all of these technologies to be used. Richard makes the point that if you balance the additional bitrate requirement against the likely impact to the viewers, UHD doesn’t make sense compared to, say, enabling HDR.

Richard moves his focus to audio next unpacking the term NGA talking about surround sound and object oriented sound. He notes that renderers are very advanced now and can analyse a room to deliver a surround sound experience without having to place speakers in the exact spot you would normally need. Options are important for sound, not just one 5.1 surround sound track is very important in terms of personalisation which isn’t just choosing language but also covers commentary, audio description etc. Richard says that audio could be delivered in a separate pipe (PLP – discussed previously) such that even after the
video has cut out due to bad reception, the audio continues.

The talk finishes looking at accessibility such as picture-in-picture signing, SMPTE Timed Text captions (IMSC1), security and the ATSC 3.0 standards stack.

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Speaker

Richard Chernock Richard Chernock
Former CSO,
Triveni Digital

Video: ASTC 3.0 Basics, Performance and the Physical Layer

ATSC 3.0 is a revolutionary technology bringing IP into the realms of RF transmission which is gaining traction in North America and is deployed in South Korea. Similar to DVB-I, ATSC 3.0 provides a way to unite the world of online streaming with that of ‘linear’ broadcast giving audiences and broadcasters the best of both worlds. Looking beyond ‘IP’, the modulation schemes are provided are much improved over ATSC 1.0 providing much better reception for the viewer and flexibility for the broadcaster.

Richard Chernock, now retired, was the CSO of Triveni Digital when he have this talk introducing the standard as part of a series of talks on the topic. ATSC, formed in 1982 brought the first wave of digital television to The States and elsewhere, explains Richard as he looks at what ATSC 1.0 delivered and what, we now see, it lacked. For instance, it’s fixed 19.2Mbps bitrate hardly provides a flexible foundation for a modern distribution platform. We then look at the previously mentioned concept that ATSC 3.0 should glue together live TV, usually via broadcast, with online VoD/streaming.

The next segment of the talk looks at how the standard breaks down into separate standards. Most modern standards like STMPE’s 2022 and 2110, are actually a suite of individual standards documents united under one name. Whilst SMPTE 2110-10, -20, -30 and -40 come together to explain how timing, video, audio and metadata work to produce the final result of professional media over IP, similarly ATSC 3.0 has sections on explaining how security, applications, the RF/physical layer and management work. Richard follows this up with a look at the protocol stack which serves to explain which parts are served on TCP, which on UDP and how the work is split between broadcast and broadband.

The last section of the talk looks at the physical layer. That is to say how the signal is broadcast over RF and the resultant performance. Richard explains the newer techniques which improve the ability to receive the signal, but highlights that – as ever – it’s a balancing act between reception and bandwidth. ATSC 3.0’s benefit is that the broadcaster gets to choose where on the scales they want to broadcast, tuning for reception indoors, for high bit-rate reception or anywhere in between. With less than -6dB SNR performance plus EAS wakeup, we’re left with the feeling that there is a large improvement over ATSC 1.0.

The talk finishes with two headlining features of ATSC 3.0. PLPs, also known as Physical Layer Pipes, are another headlining feature of ATSC 3.0, where separate channels can be created on the same RF channel. Each of these can have their own robustness vs bit rate tradeoff which allows for a range of types of services to be provided by one broadcaster. The other is Layered Division Multiplexing which allows PLPs to be transmitted on top of each other which allows 100% utilisation of the available spectrum.

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Speaker

Richard Chernock Dr. Richard Chernock
Former CSO,
Triveni Digital