AT&T (NYSE: T) is upping its 1 Gbps FTTH game with plans to build out service to parts of 38 additional metro areas.

Today, the 1 Gbps service is already up and running in 18 metros. Upon completion of this latest build, the service provider will double the amount of metro areas it serves to a total of 56.

AT&T did not specify when it will reach these markets, saying only that it will "more than double (gigabit) availability by the end of 2016."

Already, the service provider has launched the service in two new markets -- Los Angeles and West Palm Beach, Fla. -- bringing its current total to 20 of the largest metro markets.

Among the other cities it has planned are San Francisco, Milwaukee, Cleveland, Detroit, St. Louis and Indianapolis.

Since launching 1 Gbps service in Austin, Texas, in 2014, AT&T's GigaPower network has expanded to over 1 million locations.

Given the enormity of this new build, AT&T is taking an leverage-and-extend approach to its FTTH build. The provider plans to extend fiber from its existing fiber-to-the-node infrastructure for its U-verse broadband service to make those network builds fiber-to-the-premises (FTTP) capable.

Despite its promise, critics of AT&T's plans like DSLReports say that the service provider will cherrypick specific parts of each of its target markets, meaning it will equip newer housing developments with fiber.

Google Fiber (NASDAQ: GOOG) also announced today that it is considering rolling out its own 1 Gbps service in Chicago and Los Angeles but it has not made a firm commitment to either city yet.