New networks for mobile TV

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Frequency-Division Multiplexing, a modulation technology that sends multiple signals at different frequencies to get the maximum use out of spectrum bandwidth. Both technologies also use a kind of time division multiplexing to transmit specific content at specific time intervals.

But MediaFlo claims that its FLO technology has been designed to provide more-efficient use of spectrum, which would lead to higher-quality video and audio, faster channel-switching time, superior mobile reception, optimized power consumption and greater capacity.

"Some of the basics of the technology may be similar, but the way it's been implemented is different," said Albert Lin, an analyst at American Technology Research. "And these differences impact the actual user experience. FLO was designed especially to deliver mobile TV, while DVB-H is a standard based on older broadcast TV technology."

Another big difference between the MediaFlo and Modeo networks is the radio frequency spectrum each has chosen to use in building its network. MediaFlo uses the 700MHz spectrum, while Modeo uses spectrum between 1,670MHz and 1,675MHZ. Cellular operators use spectrum between 800MHz and 1,900MHz.

The 700MHz spectrum is key to MediaFlo's claim that it can build a cost-effective network, because this spectrum allows signals to be transmitted over long distances with fewer radios. The lower the frequency of operation, the farther signals propagate and the better able they are to penetrate obstacles like trees and buildings. MediaFlo can cover the entire city of San Diego, for example, with only five FLO transmitters, compared with hundreds of bay stations that must be deployed by cellular operators in order to cover an entire city with cell phone access.

MediaFlo plans to spend $800 million over the next four to five years to build its network nationwide. By contrast, Modeo estimates it will cost about $500 million over the next two years to provide service in 30 of the top markets in the U.S. It plans to offer service in a handful of cities this year, including New York. Still, Modeo's Ramke argued that his competitor's claims of cost-effectiveness are overblown.

MediaFlo's approach does have one big shortcoming. The 700MHz spectrum it taps is currently being used to transmit analog TV signals. Though in many areas of the country, MediaFlo's designated channel, Channel 55, is not being used, but there are areas where broadcasters are still using it. In those places, MediaFlo must negotiate with individual broadcasters to gain access to the channel.

This won't be an issue after the U.S. moves from analog TV to digital. A deadline of Feb. 18, 2009, was set as part of legislation that passed the U.S. Senate last year.

Though it's still too early to say which of these two companies will trump the other when it comes to providing mobile TV infrastructure, it's clear they won't be the only two players for long. As the U.S. government auctions more channels in the 700MHz band, more players are expected to emerge.

"We see this as a really huge potential market," Ramke said. "And it's still in the early stages. There's still a lot of spectrum yet to be auctioned off, so I'm sure we'll see more competition."