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TV stations to test 'channel-sharing'

In an effort to spur interest in the upcoming spectrum auction, TV broadcasters in Los Angeles team up with the CTIA to test tech that lets them share a single TV channel for broadcasting programs.

TV transmitters on top of the Empire State Building in New York City. CNET/Sarah Tew

Two Los Angeles area television stations are teaming up to launch a pilot project that will show how TV stations can share the same broadcast spectrum. This project, which is also sponsored by CTIA, the wireless industry's main lobbyist, is meant to strum up interest in the Federal Communications Commission's upcoming incentive spectrum auction.

The spectrum auction, which is set to take place sometime next year, will allow TV broadcasters to give up some or all of their wireless spectrum to be auctioned off to wireless broadband companies. The auction is strictly voluntary for TV broadcasters, and some people in the wireless industry have worried that there may not be enough interest among broadcasters to make the auction a success.

The FCC has proposed allowing TV broadcasters to share channels as one way to help free up spectrum for the auction. The idea is that two broadcasters could use one channel and a single transmitter to broadcast video streams from two stations. This could lead to a more efficient use of spectrum, as well as freeing up spectrum that could then be sold to wireless broadband providers, which will use it to add better coverage and more capacity to their wireless networks.

KLCS and KJLA, the two stations in Los Angeles that will be participating in the pilot project, will essentially combine their broadcasts and transmit them over a single 6 MHz TV channel. The idea is that the TV stations will demonstrate that they can still broadcast their existing high-definition and standard-definition TV content at a high quality on a single channel as opposed to taking up two channels. Consumers won't notice the change while channel-surfing because the channel numbers they see displayed are unrelated to spectrum channels.

The test will begin as soon as the FCC approves the pilot project. Alan Popkin, director of TV engineering, at KLCS said he hopes to complete the test by the end of March. The results of the pilot will be reported to the FCC and other broadcasters will be able to evaluate the findings to see if channel-sharing benefits them.

"This is an interesting approach to a very real problem," he said. "There's a finite amount of frequency available. And we are trying to figure out how much we can pack into a 6 MHz channel. In other words, we need to figure out if we can squeeze 10 pounds into a 5 pound bag."

Popkin continued, "We aren't saying whether or not broadcasters should or should not channel share," he said. "We're just trying to see what's possible."

Indeed, the technology to compress data is getting better everyday. And Popkin said what is possible today in terms of video compression was impossible only five years ago. Popkin hopes the data that the pilot generates will give his team and other broadcasters evaluating their options a better idea of what can be done and what the savings they might expect when it comes to channel sharing. He also hopes to evaluate any possible hurdles.

"We want to determine actual limits of what we can and cannot do with the current technology," he said. "And the results will speak for themselves."

Scott Bergmann, vice president of regulatory affairs for CTIA, said that a successful pilot project on channel sharing is a win-win-win for broadcasters, the wireless industry, and consumers. He said this could be a real opportunity for broadcasters who don't want to give up any of their programing to participate in the auction. And they can use those proceeds to reinvest in their businesses. The wireless industry also wins because it could free up additional wireless spectrum that will ultimately be used for mobile broadband services. And customers win because if broadcasters can successfully channel share without degrading broadcast quality, this means consumers don't lose video programing and they still benefit from faster mobile broadband speeds and additional capacity.

"We all have the same goal," Bergmann said. "We want to see a successful incentive spectrum auction."