Google's interest in the 700MHz spectrum auction has not been a secret. Google chief executive Eric Schmidt said back in August that the company would "probably" bid in the auction, and Google announced several weeks ago that it was preparing all the necessary materials to make a bid. Now, at last, Google is making it officially official.

The company will file the required documents with the FCC on December 3, but the documents will remain confidential and Google won't speak further about the issue in public. That's due to FCC anti-collusion rules that prohibit bidders from discussing strategy with each other in private or through public channels.

Chris Sacca, Google's head of special initiatives, stressed again in a blog post what Google has been saying throughout the year: "open access" rules on some of the spectrum will make this auction one of the most important in recent memory.

"Regardless of how the auction unfolds, we think it's important to put our money where our principles are," he wrote. "Consumers deserve more choices and more competition than they have in the wireless world today. And at a time when so many Americans don't have access to the Internet, this auction provides an unprecedented opportunity to bring the riches of the Net to more people."

So long as the $4.6 billion reserve price on the 22MHz of C block spectrum is met, the auction winner must support any application running on any device across the network it eventually builds. Should that reserve threshold not be met, however, the spectrum will be auctioned again, this time without the rules in place. Google's presence in the auction should ensure that the auction exceeds the reserve, as the company is unlikely to let the bidding remain under the reserve price unless Google is wining the auction.

Assuming that the bids exceed the reserve, though, it's not clear yet that Google's interest lies in owning spectrum and building out a major wireless network. Google has already had great success with its lobbying efforts, in large part being responsible for getting the FCC to impose the open access rules in the first place. The pressure of the auction has already led Verizon Wireless to open its own network to any CDMA-compatible device, something that will start in the second half of next year.

Is all of this enough for Google, or does the company truly want to win a chunk of spectrum? We won't know for a while. Although the auction starts on January 24, 2008, bidding could last several months before a winner is announced.