Google has thrown its weight behind the Federal Communications Commission's (FCC's) plans to turn the vacated 700MHz radio spectrum into an open wireless network. 

The proposal would force the owner of the spectrum bands to allow access to any device, meaning that users would not be locked into subscribing to a carrier in order to use a mobile device, such as a smartphone.

Google pledged to bid at least $4.6bn for the spectrum block should the FCC decide to adopt the plan, which has been put forward by FCC president Kevin Martin.

The sum would meet the proposed reserve price and ensure that the spectrum would not be sold off at a discount over traditional 'closed' frequencies.

However, Google's pledge is largely a symbolic show of support for Martin's plan, as the final selling price of the two bands is expected to be well above $4.6bn.

"Today we are putting consumers' interests first, and putting our money where our principles are," Chris Sacca, Google's head of special initiatives, said on the official Google blog. 

Google chief executive Eric Schmidt has written to Martin (PDF) explaining the search giant's proposals. 

Schmidt wrote that Google would bid at least $4.6bn as long as the FCC ensured that the band would be free for any device, service plan, network provider and software application.

"I want to personally applaud your leadership and courage in making the public case for new market entry," Schmidt told Martin.

"In short, when Americans can use the software and handsets of their choice, over open and competitive networks, they win."

Google's efforts are not without their critics, however. The Cellular Telecommunications Industry Association (CTIA) has dismissed Martin's plan as "Silicon Valley welfare", claiming that it gives Google an unfair advantage. 

John Walls, vice president of public affairs at the CTIA, said that the pledge re-affirms his organisation's belief that the proposed deal smacks of foul play.

"The letter highlights Google's scheme to have the auction rigged with special conditions in its favour," he told vnunet.com. 

"Nobody should be able to buy a custom-fit government regulation tailored to their business plan."