Imagine sitting in Rice Park and downloading “Avengers: Infinity War” onto your smartphone in seconds using an Internet connection faster than most kinds of home broadband.

This hypothetical became reality Thursday when the Verizon Wireless carrier announced availability of its next-generation 5G data service in parts of St. Paul, making it the fifth U.S. city to get such super-fast wireless connectivity.

Minneapolis and Chicago were the first in April. Denver and Providence, R.I., have since come on board, and Verizon plans to light up a total of 30 U.S. cities by year’s end.

The carrier is in frenzied competition with AT&T, Sprint and T-Mobile, which are all deploying versions of 5G but are not yet offering such service in the Twin Cities.

Verizon’s 5G speeds can, at times, seem jaw-dropping. Downloads in downtown St. Paul will often reach or surpass 2 gigabits per second, which is notable since a residential-broadband hookup typically doesn’t exceed 1 gigabit.

A FEW GOTCHAS

But, for now, potential early adopters should temper their expectations. This new wireless-data offering comes with a few gotchas.

At the moment it’s available only in a small portion of St. Paul, including about a third of downtown and a few nearby areas. Verizon is being coy about precisely where 5G will work, except to say it is operational “in parts of Downtown, Lowertown and West Seventh neighborhoods around such landmarks as the Minnesota Children’s Museum, the Minnesota Museum of American Art, the Fitzgerald Theater, Cathedral Hill Park and the Alexander Ramsey House.”

Verizon said its 5G footprints in Minneapolis and St. Paul will expand over time, but didn’t provide a timetable.

“We want to make sure to let people know that coverage is expanding, but it’s not a light switch where everyone (in a city) has it,” spokesman Andy Choi said.

What’s more, the 5G network is finicky about where and how users are positioned for best results. A smartphone should be within 800 to 1,000 feet of a 5G antenna, which is often mounted on a light pole or a rooftop. Obstacles, such as window panes or tree branches, can degrade performance. Even subtle variations in phone positioning can affect it.

And while downloads are speedy — peaking at 1 to 2 gigabits per second, and mostly hovering at around 400 megabits per second — uploads are much pokier. These will get zippier over time, but Verizon isn’t specifying how fast except to say service will not be symmetrical — as fast down as it is up.

WHAT PHONES WORK?

In addition, only a few smartphones are currently compatible with Verizon 5G. These include LG and Samsung models along with a pair of Motorola phones that awkwardly need hardware attachments for 5G compatibility. No Apple iPhone model is 5G-capable.

San Diego-based telecommunications firm Inseego on Thursday released a hotspot apparatus called 5G MiFi M1000 that provides 5G-grade wireless service to nearby handsets, tablets and PCs via Wi-Fi. This business-class device isn’t intended for consumers.

But Verizon is offering enticements for average folks who might want to try 5G. Pricing is one such lure: Consumers on certain unlimited-data plans can now get 5G at no extra cost along with regular 4G LTE, and no overage charges apply. The carrier isn’t saying how long this deal will be available; it had previously charged $10 extra for 5G.

“This gets people in on the ground floor, and gives them access to speeds we just haven’t had in our hands before,” Choi said. “Pricing is competitive enough for people to give it a try.”

4G ISN’T OBSOLETE

Verizon’s 5G by no means renders obsolete its existing 4G LTE service, which will be around for years to come as the successor network is slowly built out. It’s anyone’s guess when Twin Cities suburbs will get 5G, for one thing.

But, in addition to being much faster than 4G, the newfangled 5G offers benefits that have the potential to revolutionize wireless-data use. One such advantage is reduced “latency,” or improved response times. For consumers, this would be attractive in scenarios such as multi-player virtual-reality gaming that can be nausea-inducing with too much lag.

Beyond the consumer realm, quick-response 5G would be vital for reliable, safe use of self-driving vehicles or industrial robots, among other technologies that can’t be properly harnessed over less-responsive 4G.

As Choi puts it, “We are at the beginning of something big.”