I get tired of people saying the broadcast industry is full of dinosaurs. It gets under my skin sometimes. But the thought occurs to me that maybe it bothers me so much because it just might be true.
The pace of technological change in today’s world is astonishing, and being trapped by a 1990s paradigm of television might very well be the meteor crash that wipes us out. At the same time, the fact remains that viewers really like broadcast television. A simple, linear stream of high-quality content that is always on, easy to access and easy to use continues to provide great value for the vast majority of people. But I don’t think it’s a debate anymore that viewers’ habits are changing. Viewing continues to be more and more fragmented, both in terms of the content people are watching and the devices they are watching on. And perhaps more importantly, time-shifted viewing is making up an ever increasing slice of the viewing pie. So we’re left with a question about what we could change to better service our customers in today’s world.
That’s why so many in the broadcast technical community have been talking about what we could do from a technical standpoint to unshackle the chains so that we can continue to be players in the world of video information and entertainment. The idea of a next-generation broadcast platform using a new broadcast standard has been talked about for years, but what does that mean? If the industry is given a chance to reinvent itself technically, what should we strive to look like? For this article, I’ll focus on three areas of advancement that I think should be included in any new platform: improvements in the radio link, changes in video resolutions and codecs, and the ability to introduce advanced services.
As you look at the state of the art in today’s world compared to when 8VSB was adopted by the ATSC, you’ll discover that we actually have a very “bit-efficient” standard. That is, in terms of bits delivered per MHz used at a given C/N, the current system actually stands up surprisingly well. But the ATSC standard (ATSC A/53) has always had problems in reliably delivering those bits to a receiver when the propagation path has changing characteristics (multipath or Doppler).
Performance under those conditions is significantly improved when using the newer DTV Mobile broadcast standard (ATSC A/153), but that standard requires you to give up much of the bit efficiency that was inherent in the 8VSB system to start with.
An ideal technology would give you great performance in terms of bits delivered, but also allow you to reach devices that are subject to multipath and mobility. For me, this is a critical point, and one of a few fundamental requirements that must be included in a next-gen system: Broadcast airwaves need to be able to reach unattached devices.
More and more viewing is taking place on screens other than the fixed TV in the living room of your home. A recent Council for Research Excellence study1 has said that about 2 percent of all TV content viewing happens on mobile devices. That may be a small number, but it’s really just getting started, and it’s growing quickly. Still, one could debate whether a broadcast standard should reach such devices. I’m convinced that broadcast delivery (especially of live, high-demand content) is absolutely the most efficient, and therefore the most consumer friendly, way to deliver programming. It simply doesn’t make sense to me to replicate the same data over and over and use limited spectrum resources to deliver programming on a one-to-one basis.
But what if you don’t want to reach mobile devices and instead want to focus on delivering the most bits possible to a fixed antenna? A next-generation standard could allow for that case as well. Some of the most advanced broadcast standards today have modes that offer as much as double the bit capacity (somewhere around 40Mb/s) in the same channel.
That brings up another capability that should be part of a new standard: The standard could have multiple operational modes that are flexible enough to allow each broadcaster to optimize the delivery of bits based on how difficult the channel is or what their service model is. So if I want to be in the mobile broadcast business, I can. If the demand is for OTA delivery of 4K Ultra HD video at a very high bit rate, I can choose that instead. Or even better, I can deliver multiple services each with their own bit rates and levels of robustness all at the same time, and the device itself can figure out which service is best suited for its environment.