Four network chiefs urge FCC to nix portable white space device proposalices into DTV spectrum.

The heads of the four major broadcast networks jointly sent a letter to FCC chairman Kevin Martin Oct. 11 urging him to keep in mind viewers’ expectations that their new DTV sets will work interference free as the commission considers whether to allow unlicensed personal, portable devices in DTV spectrum.

The letter, signed by Peter Cherin, president and COO of News Corp.; Robert Iger, president and CEO of The Walt Disney Company; Leslie Moonves, president and CEO of CBS; and Jeffrey Zucker, president and CEO NBC Universal, asserted that the spectrum broadcasters give up as part of the February 2009 analog switchoff will be available for the same types of applications proponents of unlicensed devices envision for DTV band white spaces.

“A rush to place millions of unlicensed devices in the TV band without extensive real-world testing” puts the success of efforts on the part of industry and government to transition broadcasters to digital in jeopardy, it said. It also threatens the investment consumers have made in new digital sets. “Consumers purchasing new digital equipment have a right to expect their equipment will work,” the letter said.

The letter reminded the chairman that FCC tests of prototype devices revealed a general failure on their part to detect the presence of DTV transmissions. Inadequate detection would allow such devices to generate co-channel or adjacent channel interference by mistakenly identifying spectrum as safe when a DTV channel is present.

The letter pointed out that “the FCC’s own tests confirmed, the proponents of unlicensed devices in the digital television spectrum have not shown that their ‘sensing’ technology is at a stage where it would effectively prevent interference in the television band.”

However, the network heads identified the use of “fixed” devices operating on frequencies where no co-channel or adjacent channel interference is possible as an appropriate application to expand the availability of broadband Internet service to consumers.

“Deploying proposed new services at the expense of tens of millions of viewers who rely on over-the-air digital television does not seem to be an efficient use of this important national resource,” it said.