While Google and Microsoft are pressing the FCC to give further consideration to "white space" networking devices that transmit in unused portions of the TV spectrum, a microphone company -- no less -- is trying to tip the balance.

Huge players like Google, Microsoft, Motorola, Sprint, and the National Association of Broadcasters are hardly the only ones interested in the FCC's ongoing white space deliberations. Shure Inc., a maker of wireless microphones, has just filed an alternative proposal arguing against a "beacon plan" backed by Google and Motorola.

In the overriding controversy, Google, Microsoft, and other companies belonging to the eight-member White Spaces Coalition and 24-member Wireless Innovation Alliance are trying to convince the FCC to open up white space spectrum for public wireless broadband access.

The NAB, on the other hand, insists that the use of white space for wireless access will interfere with TV broadcast signals.

Meanwhile, Sprint and T-Mobile are both backing a third plan, introduced by FiberTower and the Rural Telecom Group, which would introduce fixed wireless broadband services in the white spaces.

As part of a FCC filing in March to use its emerging Android environment as a white space platform, Google suggested that interference could be prevented by combining "spectrum sensing" with two technologies already proposed by Motorola: "geo-location" for safeguarding broadcast TV and so-called "beacons" for preventing interference to wireless microphones.

Shure, however, is adamantly opposed to the use of beacons, on the grounds that they haven't yet proven themselves capable of protecting broadcast news and sports crews, theatrical groups, and other wireless mike users from interference.

According to Shure's proposal, the FCC must recognize that the proposed beacon is just a concept and still needs further testing. The filing also points out the beacons also rely on spectrum sensing, a technology that has already run into a lot of problems in the FCC's labs.

Shure, however, favors the FiberTower/Rural Telecom Group plan supported by Sprint and T-Mobile rather than the NAB's position, even though many of its own users are broadcasters.

"With appropriate power limits, [a] fixed/adjacent channel approach could go far toward providing increased broadband access for Americans while maintaining much needed protections for wireless microphone services," according to Shure's proposal to the FCC.