Microsoft will try to be more convincing this time with a new proposal to use the spare TV airwaves for Internet access, after FCC’s initial refusal to authorize a prototype device crafted at Redmond.

On Monday, Microsoft will try to persuade the Federal Communications Commission to approve a new prototype device that should be able to use airwaves roaming in the so-called “white space” for Internet access, without interfering with other devices.

The “white space” is comprised of unused frequencies in the radio waves portion of the electromagnetic spectrum. Microsoft, along with industry behemoths like Intel, Google, Samsung, Philips, Earthlink, HP and Dell (grouped in the White Spaces Coalition), has been pushing the FCC to accept “transferring” the vacant analog frequencies to the Internet since late 2006, when the Congress decided to abandon the analog television in the US.

According to the timetable proposed by the Congress, February 2009 should be the month when the last analog TV signals (which operate between the 54MHz and 698MHz television frequencies) will be broadcast. This is supposed to give enough time to the FCC to test emerging technologies and to spectrum bidders to weigh their offers and investments. The stakes are high, considering that a 2005 estimate indicated a value of up to $20 billion for the entire US analog TV spectrum.

The advantages of the analog-Internet are also not to be neglected. First of all, it’s the speed: analog signals used for Internet access could allow for "single-user applications" to reach speeds of 50 to 100 Mbps. Moreover, the use of white space for broadband connectivity could also prove less expensive for consumers and more accessible than current phone and fiber-optic lines- forcing other high-speed Web service providers to lower their prices. Rural and isolated areas could profit from the “relocation” of airwaves, but Microsoft and its partners are focusing more on finding ways to connected portable devices like digital cameras, camcorders or even tiny MP3 players to the Web.

Microsoft’s first prototype failed to meet FCC’s requirements, either interfering with existing TV signals or not being able to detect those signals, to avoid interference. However, Microsoft insists that a second prototype, delivered for testing last week, worked much better. In a filling submitted on Monday, MS said the new prototype "reliably detected occupied television channels," also hinting at upcoming enhancements that should eliminate interferences with wireless microphones.

FCC’s next meeting to review Redmond’s most recent proposal is scheduled for this Thursday, but the final decision will have to take in consideration- besides the prototype’s flawless behavior- the concerns expressed by phone carriers and cable operators, who fear that their wireless PA systems will no longer function properly if unlicensed devices will be allowed to operate within the same spectrum.