The wireless spectrum auction ended last week but Google is not done lobbying the Federal Communications Commission.

On Monday the company sent a letter to the FCC outlining what it would like to do with so-called “white space” — airwaves found between broadcast channels that will become available when television switches from analog to digital early next year. Unlike the five blocks of spectrum recently up for auction, these airwaves are unlicensed and largely unused.

Google (GOOG) is proposing that the spectrum be used for mobile broadband services, including Internet access for upcoming — you guessed it — Android-running phones, which use an operating system promoted by Google. The company says it will ensure that devices operating in the unlicensed spectrum won’t interfere with TV channels or wireless microphone signals, and that it intends to provide the “technical support necessary to make these plans happen” at no cost to phonemakers.

The company said it is confident its proposal will “eliminate any remaining legitimate concerns about the merits of using the white space for unlicensed personal/portable devices.”

Google’s not the only one pushing the FCC to allow the unused spectrum to be used for mobile broadband services. Microsoft (MSFT), Dell (DELL) and Hewlett-Packard (HPQ) have also joined the “White Space Coalition.” But the proposal has drawn plenty opposition from groups like the National Association of Broadcasters, who worry that using white space for a wireless broadband service will interfere with digital TV transmissions.