These 3 cities might be next up for Google Fiber by Laura Lorenzetti @FortuneMagazine September 10, 2015, 4:38 PM EDT E-mail Tweet Facebook Linkedin Share icons Google is exploring expanding its Google Fiber service to three more cities, raising the number of towns now evaluating the high-speed service to six. Now on the list: Irvine, Calif., San Diego and Louisville, K.Y. Those cities join the ranks of Portland, Ore., San Jose, Calif. and Phoenix, which are also potential Fiber cities. Google Fiber is a super high-speed broadband internet and cable television service featuring a connection that’s up to 1,000 megabits per second (Mbps). Fast broadband is defined as speeds of 10 Mbps or more. Signups for gigabit Internet services in the U.S. have grown at a rate of 480% each year, even though it still is only available in limited areas. Google GOOG announced the service expansion on its blog and it hopes to continue Fiber’s expansion: While much of the United States still lags behind the rest of the world in Internet speeds, cities like Kansas City—where Fiber started—rank amongst the fastest cities in the world. We want to see more U.S. cities at the top of that list. Google Fiber is currently available in Austin, Tex., Kansas City, and Provo, UT. It is coming to six more cities in the near future: San Antonio, Nashville, Tenn., Atlanta, Charlotte, N.C., Raleigh-Durham, N.C., and Salt Lake City.