The wireless spectrum auction is reaching an interesting stage: After 18 rounds of bidding that began one week ago, bids for the “C block” of nationwide spectrum reached $4.7 billion, according to FCC data, reports MarketWatch. This means that FCC’s open access rules for part of the spectrum will now come into play, something Google (NSDQ: GOOG) had been pushing for. Whoever wins any of the C-Block license will be required to provide access to any compatible device, thus improving handset portability and interoperability of devices as well as, hopefully, applications.

The bids will go on until, well, no more bids come in. The govt had targeted raising roughly $10 billion from the auction, but a total of $13.7 billion had been bid for various blocks and licenses as of Thursday afternoon. All bidding is anonymous, but Verizon (NYSE: VZ), AT&T (NYSE: T) or Google would be seriously in the running. All three companies were disclosed as qualified bidders in the auction earlier this month.

RCR:  The potential winning bid for the block in round 17 sat at $4.7 billion, with the minimum bid for round 18 set at nearly $5.3 billion.