US Mobile DTV standard finally approved
By Nilay Patel 
posted Oct 16th 2009 6:33PM
posted Oct 16th 2009 6:33PM
Well freaking finally. The Advanced Television System Committee just approved the Mobile DTV standard, meaning we're finally about to see for-real mobile television in the US. LG and Samsung have already made gear for the new standard, and the tech will be demoed later today before a rollout... sometime. Still, it's heartening news to hear that it's finally ready -- over 800 stations are signed up to broadcast the new signal, which makes use of existing 6MHz airwaves to do everything from straight TV to video-on-demand and targeted advertising. Cool, so now we're what, just a billion years behind DVB adoption?
Great, another thing to steal bits from the primary HD channel.
@Jim
You got that right. Here, I made pie charts:
http://seantorbett.com/2008/08/hello-mobile-dtv-goodbye-hdtv/
US needs to be more like the other parts of the world and just start using DVB. Why cant they use DVB ?!?!?! its like HD radio and DAB
It's not like HD Radio and DAB, which is itself a weird situation.
There are actually three, not two, DTV standards. ATSC, DVB, and ISDB. All have fairly substantial adoption. ATSC was developed at the same time as the two other standards and has no substantial advantages or disadvantages over the others except in that the industry hasn't demanded certain services as quickly as they have for the others.
HD Radio on the other hand is some proprietary virtual snake-oil that was developed to fool the FCC into thinking they can have their cake and eat it if they'd just hand a now demonstrably dishonest company a monopoly on the technology to use. In fairness, HD Radio also provides a migration path for AM radio which, at the time, DAB didn't provide, but essentially the thing HD Radio pretends to do is provide a way to have both digital and analog on the same frequency, thus meaning the FCC doesn't have to clear spectrum for it. The downside is that it doesn't work properly, and anyone trying to take advantage of the "digital" channels soon finds that mobile use, especially in any semi-urban setting, is a joke, with the additional subchannels disappearing and re-appearing.
Ubiquity Wireless lied about their intentions with HD Radio, making a substantial part of the standard proprietary and undocumented, and if I were an FCC commissioner I'd be using it as an excuse to run far, far, away from the standard and get on board with DAB and its AM equivalent, Digital Radio Mondiale. But the FCC is the FCC, so there's no chance of that.
First off, regular old DAB is crap. Of course, that has in large part to do with the spec being started back in the '80s, but the error protection schemes are archaic. The system arguably (especially as deployed) is arguably worse than plain old FM. DAB+ fixes a lot of the problems, though, as do other modern competing standards.
Second, most of these comments ignore the history of the spectrum use. US standards bodies tend to create standards that don't use frequencies already used by other US standards; European standards do the same for European uses. In the case of DAB, some of the popular required bands are used for other things in the USA. For example, Band II is the VHF band used for regular VHF analog TV broadcasts. Most European countries used VHF for black and white broadcasts in now obsolete formats and then when they moved to color switched standards to PAL (or SECAM) on UHF frequencies. The US stuck with VHF because we used a color NTSC standard fully backwards compatible with the old black and white broadcasts. This means that the oldest and strongest TV stations are VHF in the US, unlike in Europe where everything was UHF.
Third World countries are more likely to have unused frequencies simply because they have less uses. It's the same reason that Japan and South Korea have also operated on their own special frequencies for many things, including cellular. They had too many incumbent technologies on the "international" frequencies.
Lastly, it's hilarious to see completely European-invented standards described as global or international, only because the EU consists of many different countries, even at times when the standards cover fewer people than US standards. In 2006, despite DAB having been around for a long time, only about 500 million people were theoretically in range of a DAB station, with real coverage only extending to the UK (where sound quality was often worse than FM stations, due to compression choices of the MP2s) and Denmark. That's not that much more than the entire North American population. There's also only about 20-30 countries really deploying DAB; if we counted each US state separately, you could get similar claims that any US standards was "international." And of course any single-Chinese standard would cover even more people than many of these "international" standards.
Because the US has a lot more people in rural areas, for which ATSC is more suitable. DVB deals better with multipath, but doesn't have as much range.
If you think DAB is bad (and I'm prepared to believe you that it is), you haven't seen HD Radio. It's essentially only usable if you're listening to the primary channel, largely because when the digital side cuts out the redundant analog part kicks in. Because there's an analog component HD Radio multiplexes with more than two subchannels sound like crap, and while there's a "robust" version that's supposedly less susceptible to interference, it's so low bandwidth that it's useless unless analog has been turned off by the station completely.
What was needed was for the FCC to allocate spectrum for digital and hand it over, but the FCC wasn't willing to do that, wasn't willing to acknowledge digital wasn't going to happen, and went for the third route, picking a proprietary system that just doesn't work.
DAB, incidentally, was designed during the nineties (hence it's based upon MPEG 1 Audio), and Digital Radio Mondiale is a recent development. Either way, DAB would have been a better solution, even plain old DAB (but, as you say, DAB+ was also an option by then) than HD Radio. If DAB really was unacceptable, then the FCC should have set going the same kind of open process that got us ATSC - indeed, ATSC could have been the basis of an open standard for radio by itself.