Mobile DTV standard in the US gets raised to "proposed standard" status

Yeah, we know it's hard to believe but it seems it is actually true; the mobile DTV technologies from LG and Samsung have officially reached the final step on the way to becoming the formal ATSC-M/H standard. In the next four weeks the members will give it the final blessing, which means there should be plenty of mobile TV devices announced at CES in January. This should also mean that with any luck we'll be able to watch DTV on the go in 2010. At this point it seems that 70 of the almost 1800 full power stations in the US plan to launch mobile service later this year. Now for the bad news; the bandwidth for these mobile broadcasts will come from the existing spectrum, so in other words say hello to just a little more compression from your local HD affiliates.

[(Unverified) Posted Jul 7th 2009 12:14PM]

Wow, I sure this has a small foot print on the HD channels. I wonder what our local CBS affiliate will do when they are asked to do this.. As it is, they don't want to give up any bandwidth for TVGOS because they are scared of giving up any bandwidth. I can't imagine what they'll do if they have to add this service too.

[(Unverified) Posted Jul 7th 2009 5:46PM]

Why oh why do we have to continue to use our own proprietary format? I certainly hope that even if this gets mandated, we'll still get mobile devices with DVB-H support so we can use them when abroad.

[(Unverified) Posted Jul 8th 2009 7:55AM]

We have to have our own mobile TV standard because the US already has ATSC and has already standardized upon it. ATSC and DVB-H cannot exist on the same multiplex (DVB-T and DVB-H can, and ATSC and ATSC-M/H can), so if we decide that we're going to go DVB then one of two things has to happen:

1. We have to throw out ATSC and introduce DVB-T, forcing tens of millions of households to throw out their digital TVs and buy new ones supporting DVB-T instead.
2. We have to allocate an entirely different set of frequencies for DVB-H broadcasting.

Now, personally, if I was appointed dictator of the US, then I'd probably tell everyone (2) is the way to go and get some microwave spectrum cleared for it, not because I'm a fan of DVB-H (I really don't give a crap) but because I'd rather see the ATSC broadcasters use as much of their bandwidth as possible on their HD channels, especially as we're stuck with MPEG2 for the time being. But, alas, unfortunately for you guys, I'm not likely to ever be appointed dictator. Sorry about that.

Anyway, that's the bottom line. DVB-H is not compatible with ATSC, so would need its own frequencies or would need the US to switch to DVB-T, neither of which are ever going to happen.

And, y'know, in the end, it doesn't matter much. Even back in the bad old days of PAL vs SECAM vs NTSC, TV manufacturers would frequently make TVs that had all the circuitry necessary to support all three standards (though the control panels would generally lock the TVs to a particular system) as it didn't add much to the cost.

I'd hazard a guess that once the patents run out on the low level radio systems, making TVs that support DVB and ATSC is going to cost no more than making TVs that support one or the other. That's right, I said no more, not "very little more". You're essentially supporting two different multiplexing and modulation schemes in the hardware, the rest is software.

How hard is supporting two different multiplexing and modulation schemes in hardware? Most TVs do multiple modulation schemes already. OTA ATSC is 8VSB, while cable is either 16VSB or 256QAM. Virtually all ATSC TVs support all three modulation schemes. Multiplexing is harder - ATSC uses one big-ass carrier, while DVB splits the carrier into lots of little ones (OFDM), and yeah, that probably requires two different circuits.

And the software? The software differences between DVB and ATSC are limited largely to "How do I extract the MPEG2 or H.264 stream for this channel? How do I find out what channels are on this multiplex? And how do extract the OTA EIT?"

In the end, I don't think it's a major issue for the US to have "its own standard". I think the vast majority of receivers will be designed to work with all the standards available. The thing I don't like about this is we're still stuck with broadcasters having to reduce their available HD bandwidth. That's the real objection, the FCC should be clearing space for mobile broadcasting, or even working on a path towards H.264.