AT&T announced plans on Friday for a broader rollout of super-fast 5G mobile phone service for consumers, reaching parts of 15 cities within the next few months. AT&T was the fourth of the four major carriers to reveal its initial plans for 5G phone service, allowing customers to weigh the various options for getting connectivity that could be 10 to 50 times faster than the average 4G download speed.
AT&T said its new 5G service would start in parts of Indianapolis, Pittsburgh, Providence, Rochester, and San Diego. By February, the service would also encompass parts of Boston, Las Vegas, Milwaukee, New York City, San Francisco, Birmingham, Ala., Bridgeport, Conn., Buffalo, N.Y., Louisville, Ky., and San Jose. The limited rollout is similar to Sprint and Verizon, while T-Mobile has said it’s looking at a near-nationwide 5G offering starting on Dec. 6.
AT&T customers will have to buy a 5G-compatible phone to use the new service, and is only offering one model to start: Samsung’s Galaxy Note 10+ 5G. The phone costs $1,300, though AT&T will be offering installment purchase plans and discounts for trading in old phones. Handset makers across the industry are expected rapidly to introduce a slew of additional compatible phones next year, including rumors that Apple’s 2020 iPhones will have 5G modems.
As far as monthly pricing, AT&T joined its rivals Verizon, T-Mobile, and Sprint by adding 5G service to its latest unlimited data plans without charging a premium. Only Verizon initially planned to charge an extra $10 per month for 5G, but quickly dropped the plan in the face of tepid consumer demand.
That doesn’t mean 5G networks won’t help the carriers financially, however. In addition to providing consumers with faster connections, the 5G networks also increase capacity for the carriers, making it less expensive for them to supply data over the airwaves. So even if revenue does not go up with 5G, costs could decline.
AT&T said it would offer 5G using airwave spectrum at around the same frequencies as today’s 4G service. The carrier has previously offered 5G service for business customers using much higher frequencies. The advantage of the lower bands is that such signals travel much farther and can penetrate buildings. But higher bands carry far more data and offer faster download speeds.
Both Sprint and T-Mobile are also relying on lower bands for their 5G offerings, sacrificing some speed in favor of broader coverage. Only Verizon is relying on higher bands for consumer phone service, at least so far. That means even in cities where Verizon has 5G service, its super-fast network is only available in small blocks, compared to the larger neighborhoods and towns covered by competitors’ service. But Verizon offers faster download speeds than rivals.
Verizon added parts of three cities–Boston, Houston, and Sioux Falls–to its 5G network this week, bringing its total so far to 18. The carrier has said it plans to reach at least 30 cities by the end of the year.
Sprint offers 5G service in parts of Atlanta, Chicago, Dallas, Houston and Kansas City plus Los Angeles, New York City, Phoenix and Washington D.C.
T-Mobile, which is trying to acquire Sprint, recently said it plans to offer lower band 5G service starting on Dec. 6, covering 5,000 cities and towns where 200 million people live. AT&T says it will also be nationwide in the first half of 2020.
More must-read stories from Fortune:
—Obama worries that tech has led society astray
—Tesla could deliver ‘full self-driving’ within weeks. What that means for drivers—and Tesla’s stock
—The game industry is suffering from a battle royale ‘hangover’
—Most executives fear their companies will fail if they don’t adopt A.I.
—How giving thinkers and tinkerers room to experiment builds a better company
Catch up with Data Sheet, Fortune’s daily digest on the business of tech.