Verizon's launch of 5G home Internet targeted four cities dominated by either Comcast or Charter, and Verizon says it will continue to bring the service to densely populated areas dominated by cable companies.

The launch cities that got Verizon 5G home Internet this week were Houston, Indianapolis, Los Angeles, and Sacramento. Comcast is the main cable provider in Houston, Indianapolis, and Sacramento, while Charter leads the way in Los Angeles and covers part of Indianapolis, according to ISP tracker BroadbandNow.

That's no coincidence. Verizon Chief Technology Architect Ed Chan told Ars that Verizon is focusing on using the $70-per-month wireless home Internet service to compete against dominant cable companies.

Verizon is targeting cities "where cable is today, just foundationally, because we definitely see the customer demand in those places," Chan said.

Cable companies have generally avoided competing against each other, so many US cities have just one provider. When there are two cable providers in a city, they often divide the city up into non-overlapping territories.

The cable industry has "done a very good job of always aligning to a single cable-only provider" in each area, Chan said. "Those customers are very eager to get a choice in their broadband provider."

Besides cable providers, the four launch cities all have AT&T wireline service. It's mostly AT&T DSL or fiber-to-the-node, with some fiber-to-the-home.

Comcast and Charter dominate home broadband

There are tens of millions of customers in that situation. At speeds of at least 25Mbps downstream and 3Mbps upstream, Comcast is the only choice for 30 million Americans, and Charter Communications is the only choice for 38 million Americans, research based on Federal Communications Commission data found recently.

The same report found that telcos like AT&T and Verizon have largely failed to offer high speeds to rural homes. The telcos' fiber deployments have mostly targeted more populous areas, which generally have cable providers. Verizon's early 5G home Internet deployment follows the same pattern.

Verizon says that its 5G home Internet service provides download speeds of 300Mbps to nearly 1Gbps with very low latency and has no data caps or throttling. The fixed 5G service uses a router in the home and, in some cases, also requires an exterior antenna on the home.

Verizon provided no word on where else it will bring the wireless home Internet service. Even in the four launch cities, it's only available in certain areas, and Chan would not say how many households it is available to today. You can check availability by address here.

"We're keeping that close to our vest in this particular case," Chan said.

You wouldn't expect such secrecy if the number was impressive, because Verizon has never been shy about touting the number of people its 4G network can reach.

Verizon silent on next cities

Verizon chose the four launch cities partly because city officials there provided more "cooperation" on deployment and "seemed to be more forward thinking," Chan said. He said the launch has brought service both to single-family homes and multi-unit dwellings.

"We actually are more residential-driven in this launch rather than the downtown [areas]," he said. "You will see us going after the downtown in some areas as well." He said Verizon also expects to make fixed 5G Internet available to small- and medium-sized businesses.

Verizon could bring its 5G home Internet to the Northeast US, where the company's wireline division offers a mix of DSL Internet and fiber-to-the-home. But again, Verizon says it isn't ready to name any other cities where it might bring 5G home service.

In Verizon's wireline territory, the areas without the fiber FiOS service are probably more likely to get 5G home Internet. Customers with FiOS already have fast Internet speeds and low latency, so "the 5G side of this equation is not as great a value to those customers," Chan noted.

But Verizon's wireline territory has "plenty of areas that don't have FiOS deployed," he said. Installing fiber everywhere is costly and complicated, so "the better thing to do in these cases would be to bring fiber to the tower, essentially the small cell infrastructure, and then go wireless the last mile of the way," Chan said.

One important question is whether Verizon will bring 5G home Internet to rural areas and other parts of the country that have DSL service but no cable providers. DSL-only areas are really in need of faster Internet service, even more so than cities dominated by a single cable provider.

For 5G home Internet, Chan said Verizon is focusing on places with the most demand—likely ruling out sparsely populated areas, at least in the near future. Chan said that Verizon's 4G mobile Internet is already a good option for people in rural areas. However, Verizon 4G's latency is much worse than cable or fiber, and even "unlimited" Verizon 4G plans can be throttled after customers use at least 22GB a month.

"It's too soon for us to tell" whether Verizon will bring 5G home Internet to rural areas, Chan said. "Right now, we're focused so much on bringing the maximum benefit to the dense areas."

Low latency, fewer limits

Verizon is bullish on 5G for home Internet partly because of its low latency. Chan said latency is about 2-4ms each way, or less than 10ms for a round trip. Even Verizon FiOS's latency is more than 10ms, according to in-home testing data from the Federal Communications Commission.

Latency is basically imperceptible at the level achieved by 5G, making it possible for applications to "run on the network instead of running on the device," Chan said. Online gaming, robotics, and augmented reality will benefit greatly from that, he said. "There is a magic number of round-trip latency of about 25ms, where humans will feel the difference when you have that kind of lag or lack of response," Chan said.

Chan said mobile 5G latency is about the same as fixed 5G but that it's just in testing, because mobile 5G isn't commercially available yet. It would be a huge improvement over 4G—Verizon's average 4G latency is about 62ms, worse than AT&T's industry-best average of 54ms, according to testing by OpenSignal. AT&T was the only provider with 4G latency of less than 40ms in any individual city, achieving that mark in Chicago and Milwaukee.

Verizon is rolling out 5G as a home Internet service first because it's easier to guarantee solid connections to fixed locations than it is to millions of people roaming around large areas.

Verizon's 5G home Internet is based on Verizon's own technology rather than the 5G NR (New Radio) global standard. Verizon plans to switch to 5G NR later on but was able to launch now using its own Verizon 5G Technology Forum version of 5G.

While Verizon 4G relies heavily on low-band spectrum in the 700MHz range, the 5G home Internet uses 28GHz spectrum in the launch cities. Such high-band spectrum is challenging to use because it's less able to cover long distances and penetrate building walls. But there's a lot more high-band spectrum than low-band spectrum available, Chan noted.

In geographic areas where Verizon had 100MHz of spectrum serving 4G customers, the company is deploying up to 800MHz of spectrum for 5G, Chan said. Verizon 5G also uses many more antennas than 4G in a Massive MIMO setup. The network can thus serve more data without getting congested.

That's one big reason why the 5G home Internet service offers unlimited data without any throttling that we know of. By contrast, Verizon reserves the right to throttle unlimited mobile 4G plans after customers use 22GB a month—Verizon's throttling infamously affected the Santa Clara County fire department while it was fighting California's largest-ever wildfire.

The 5G network will have "massive capabilities," Chan said. "It's not the same system anymore... we are not treating this the same way as 4G."

Throttling on mobile 5G still possible

But that doesn't mean 5G mobile plans will be free of throttling. When asked whether Verizon will throttle 5G mobile plans, Chan said it's "too soon to tell; I would have to leave that to my marketing compadres and see what they want to do in that case. That is still to be determined."

There will also be differences in how Verizon deploys mobile 5G to rural areas as opposed to urban ones. Low-band spectrum is crucial for covering the large spaces in rural areas. 5G can use any spectrum, and in rural areas "it will probably be a combination of all of them," Chan said. That means rural 5G will use low-band frequencies, mid-band, "and some high-band depending on where the rural areas are," he said.

Just as with 5G home Internet, rural areas can expect to wait longer than urban ones for deployment. "It's a matter of timing," Chan said. "Like any business, you always go after where the most benefits are because that's where most of the users are."

Disclosure: The Advance/Newhouse Partnership, which owns 13 percent of Charter, is part of Advance Publications. Advance Publications owns Condé Nast, which owns Ars Technica.