A rival offering from Google Inc., known as Google Fiber, is available in Kansas City and is coming soon to Austin and Provo, Utah. Smaller companies and public utilities offer or plan such speeds in a handful of other markets throughout the U.S.
AT&T Inc. said Monday that the specific number of markets beyond its initial four will depend on discussions with local officials and assessments of potential demand. The company said it may start building some of the new networks by the end of the year.
None of the new markets are in the Northeast because AT&T doesn't have landline operations there. Verizon serves much of that area and has been offering its own fiber-optics service, FiOS, though its top speed is at half of what AT&T is planning.
Verizon said that although it hasn't seen widespread demand for a 1 gigabit service yet, the rival offerings are indicative of growing demand for super-fast Internet.
Such speeds are common in parts of Asia and Northern Europe, but they are not as prevalent in the U.S., where some rural households are still stuck on extremely slow dial-up services. Internet providers have been reluctant to spend the billions of dollars needed to extend fiber-optic cables into each and every home. The companies have been largely content to use existing, but slower cable TV lines.
Part of the problem is demand: Many applications and tasks that might take advantage of the higher speeds haven't been developed yet. But they won't get developed if the speeds aren't available.
But higher speeds will make a difference as people connect more smartphones and other gadgets to their home networks and expect to watch quality video on them.
Lori Lee, senior executive vice president for AT&T's home solutions business, said that just as consumers might not have imagined a need for smartphones a few years ago, they might not see a need for higher Internet speeds today. Such a need, she said, will become clearer over time.
"We see this as where the world is going," Lee said. "We are about skating where the puck is going and not necessarily where it is today."
AT&T is also targeting small and medium-size businesses with the new offering. Lee cited video conferencing as one application made practical by higher speeds.
The new metropolitan areas targeted by AT&T are: Atlanta, Augusta, Ga., Charlotte, N.C., Chicago, Cleveland, Fort Lauderdale, Fla., Fort Worth, Texas, Greensboro, N.C., Jacksonville, Fla., Houston, Kansas City, Los Angeles, Miami, Nashville, Tenn., Oakland, Calif., Orlando, Fla., St. Louis, San Antonio, Texas, San Diego, San Francisco and San Jose, Calif.
In many of these markets, only certain cities and towns will get the service. All told, AT&T is targeting about 100 municipalities.
AT&T didn't announce prices. In Austin, the service costs $70, or $120 when bundled with television service.
Cable Internet services typically cost less, but deliver slower speeds. And with most cable services, sending data is typically slower than receiving content, making online backups and video sharing impractical or painfully slow. AT&T's service is symmetrical, so uploads and downloads are comparable.