Mobile TV: Mobile broadcasts have to contend with reflected signals that constantly change. Photo by Paul Wootton

It’s hard enough getting digital TV from an antenna in your house. Forget about in a car. But Samsung and LG aim to change that. In a scary reminiscence of Blu-ray vs. HD DVD, the two companies had been developing similar but incompatible standards (called AVS-B and MPH) for digital TV that can be delivered on the road.

But the two companies shook hands today on an agreement to work together on a common standard for the US. As we reported a few months ago, moving your TV around poses all kinds of problems for reception. TV signals bounce off buildings and other cars, so you get dozens of reflected signals, that change constantly, confusing the decoder. You also get the Doppler effect—with waves scrunching up as you drive toward an antenna and spreading out as you drive away. The LG and Samsung technologies fix these problems with heavy-duty error-correction so the tuner can be sure it got the right information.

Unlike the MediaFLO mobile TV that Verizon and AT&T are delivering to cellphones, the new standard will come from your local TV stations in a version of the digital ATSC standard that can be transmitted alongside their HD broadcasts and come from the same antenna. So it’s a way to get local weather, news and sports, plus network TV. And it may be free, like over-the-air broadcasts to your home.

The next step is for the companies to hash out the technology with the Advanced Television Standards Committee (ATSC). Rough prediction is that the technology will be available to TV stations and in receivers in 2009.