Some of the largest companies in the technology world are putting their names behind a move to build a free wireless network from so-called 'white spaces'.

Microsoft and Google are among the companies that have backed a recent Federal Communications Commission (FCC) report which concluded that the establishment of a free wireless network in the empty spaces between broadcast channels would not interfere with any other device, paving the way for the system to move forward.

Anoop Gupta, corporate vice president of technology policy and strategy at Microsoft, praised the FCC decision in a statement released shortly after the report was published.

"The FCC has now crossed an important milestone in the path to establishing final rules of the road for the use of the white spaces," he said.

"Clearly the FCC's internal work and its test process have provided enough information, guidance and technical input to move the process forward in allowing unlicensed use of the white spaces."

Google media counsel Richard Whitt offered similar praise for the FCC in a recent posting to the company's public policy blog.

"This news should be greatly encouraging for American consumers," wrote Whitt. "The FCC now has more than enough information to develop appropriate rules that protect TV stations and wireless microphone users from harmful interference, while at the same time allowing innovators and entrepreneurs to develop technology that productively uses these airwaves."

Not everyone was thrilled with the FCC's conclusion, however. The National Association of Broadcasters (NAB) is worried about the effect the spectrum may have on TV broadcasts, and has urged the FCC to take another look at the report before moving forward.

"It would appear that the FCC is misinterpreting the actual data collected by their own engineers," said NAB executive vice president Dennis Wharton in a written statement.

"Any reasonable analysis of the report would conclude that unlicensed devices that rely solely on spectrum sensing threaten the viability of clear television reception.

"Basing public policy on an imprecise version of a 149-page report raises troubling questions."