With the Federal Communications Commission set to vote Nov. 4 on whether using empty TV spectrum can be used for unlicensed wireless services, arguments for both sides are getting some serious star power.

These so-called "white spaces" sit between broadcast TV channels, and they will become available when broadcast TV stations switch from analog to digital next year. Companies like Hewlett-Packard, Google, and Microsoft want this spectrum to be available for wireless Internet services. Broadcasters, telecoms, and wireless microphone companies say that use of white spaces could interfere with nearby spectrum bands.

During a conference call Monday, Microsoft said that Bill Gates would be personally calling FCC Commissioner Robert McDowell to lobby for unlicensed white-space use. In a recent interview with the The Washington Post, Gates argued that companies would be able to offer innovative wireless services, and likened the white spaces to Wi-Fi, which operates in unlicensed spectrum bands.

"Why did Wi-Fi happen? It happened only for one reason -- there was a global, unlicensed frequency band where there was no requirement for people to come forward and seek permission or pay money," Gates said.

FCC Chairman Kevin Martin recently said he would support use of the white spaces as long as it doesn't interfere with broadcasts.

Opponents of unlicensed use already have slammed the FCC's technical report, which generally approves white-space usage. Even country music artist Dolly Parton has entered the fray and sent a letter to the FCC urging a delay of the vote until more interference tests are completed.

"As someone who uses the white spaces and knows the value of them for the work that I and many of my friends do around the country, I ask the FCC to recognize the entertainment industry's valuable contribution to the cultural life," Parton wrote. "I can unequivocally confirm that the importance of clear, consistent wireless microphone broadcasts simply cannot be overstated. This industry relies on wireless technology and is in jeopardy of being irreversibly devastated by the commission's pending decision."