Google is challenging Verizon's vision of what sort of open network it will run on the spectrum it recently acquired in the Federal Communications Commission auction for $4.7 billion. Under the auction rules, Verizon is required to build an open network to which users can connect any legal device and run the software of their choice.

But in a May 2 filing with the FCC, Google contends Verizon has no such intentions. Instead, Google claims, Verizon plans to institute a "two-door" policy: one door for open access devices and applications and another door for "closed" devices that only support Verizon's proprietary applications.

In the filing, Google urged the FCC to deny Verizon a license to use the spectrum until it fully commits to an open network.

"Verizon has taken the public position that it may exclude its handsets from the open access condition," Google states in the filing. "Verizon believes it may force customers who want to access the open platform using a device not purchased from Verizon to go through 'Door No. 1,' while allowing customers who obtain their device from Verizon access through 'Door No. 2.'"

It's door No. 2 that troubles Google, which is heavily invested in promoting its own Android open-source mobile platform. As the search giant sees it, Verizon plans to deny Verizon customers full open access to competing devices and applications.

"[The FCC] mandates opening the C Block network for the use of any device, and for the use of any application on any device, regardless of whether an end user obtains the device from the licensee, another service provider, a manufacturer or other third party," Google states.

Verizon promptly dismissed Google's concerns.

"Google's filing has no legal basis.  It's really no surprise that despite not winning spectrum, they continue to try to change the rules and further their own business interests through the regulatory process," Verizon spokesman Jeffrey Nelson said in a statement, adding that Verizon plans an FCC filing in next several days to counter Google's claims.  

Last summer, Google lobbied the FCC into adopting open access standards for the prime C Block of spectrum, a notion Verizon initially opposed in a lawsuit, contending that the spectrum should go the highest bidder with no restrictions. Verizon eventually dropped the legal challenge.

"Verizon Wireless … understood the FCC's rules for using that spectrum in advance of the auction," Nelson said. "Of course we'll abide by those rules.  As we work to put the spectrum we won to good use, if Google or anybody else has evidence that we aren't playing by the rules, there are legitimate and expedited ways to address that."