Report: Google considers becoming a wireless carrier
There was also some talk last year that Google would work out a deal to become a Sprint MVNO. Now, Google is said to be interested in working out an MVNO deal with Verizon or T-Mobile. Verizon is the largest carrier in the U.S., while T-Mobile is considered the most innovative operator in the industry.
There is speculation that Google would offer a hybrid service similar to Republic Wireless and Freedom Pop. These carriers offer their customers low cost plans by using Wi-Fi connectivity to carry calls, texts and data. Once outside the range of a Wi-Fi signal, the carriers connect using a 3G or 4G signal from Sprint. Google's hybrid service could use Wi-Fi from Google Fiber and a regular cell signal from whichever carrier it partners up with.
source: TheInformation via AndroidAuthority