For eight full days spread across December and January, from dawn until dusk, Earl Lum of EJL Wireless Research drove around Sacramento looking for Verizon's 5G.

"By the end of it, I got pretty good at geomapping," he said.

It was no small task. In traversing the city, Lum had to travel through a few "dodgy" neighborhoods, got chased by a dog, and had other adventures. "I wasn't happy with that dog," he deadpanned.

To find the company's network in the city, Lum looked up the street addresses serviced by Verizon's 5G Home service and then drove around until he spotted the cell sites that provide service to those addresses.

The results of Lum's work are significant -- and not inspiring. Verizon is currently using the network to sell stationary, in-home broadband services -- $70 per month for speeds of 300 Mbit/s and up -- in a challenge to wired Internet providers like Charter and Comcast. Verizon has said it plans to expand that effort into more cities at some point later this year, and will also launch mobile 5G services sometime this year. (See Verizon Confirms Mobile 5G in 'Early' 2019.)

So what does Verizon's initial 5G effort in Sacramento (one of its four 5G Home cities) look like? Below are three observations Lum made while surveying what he estimated were 99% of Verizon's 5GTF cell sites across Sacramento (the analyst is selling a complete report of his work on his website).

1 – Verizon's 5G Home service covers around 10% of Sacramento.

"It's pretty sparse," Lum concluded of the network's coverage, adding that he counted "several hundred" 5G sites.

This doesn't come as a total surprise. After all, Verizon's network is exclusively using the operator's 28GHz spectrum, which is ideal for carrying huge amounts of data but not for covering large geographic areas. Verizon has said 28GHz signals can travel around 1,000 feet, but Lum said he mostly calculated signals traveling about 500 feet, based on the locations of the 28GHz transmitters and potential customers' addresses (Verizon, for its part, boasts of a further reach in some cases, as do some other surveys of Verizon's 5G network).

"It's not 600MHz," Lum noted, pointing to the kind of low-band spectrum that T-Mobile plans to use for its 5G deployment. Such low-band spectrum can cover far more geographic territory than millimeter-wave spectrum like 28GHz.

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2 – All of Verizon's 5G transmitters were attached to streetlights.

While this might not seem like a big deal, it kind of is. Lum explained that all of Verizon's 5GTF transmission radios were attached to the tops of streetlights and not to any other structures, like traffic signals or rooftops, possibly because Verizon only has permission from the city to use streetlights (Verizon inked a public-private partnership with Sacramento in 2017).

This situation reflects the fact that small wireless transmitters -- generally referred to as small cells -- have been difficult for operators to deploy in part because they typically sit on city-owned infrastructure. And, as anyone who has dealt with local regulators knows, getting a city's permission to make changes to city-owned stuff is challenging at best. For example, tower company Crown Castle typically allocates a full two years to get local approvals for small cell installations.

Another, and perhaps more important, possible takeaway from Lum's work is that streetlights probably aren't the best locations for a 28GHz network that provides mobility services. Lum explained that, to create an efficient grid of coverage for cars, dog walkers and others, operators likely would want to install their equipment on top of traffic signals at intersections, not on streetlights in the middle of a neighborhood.

"You don't need a site in the middle [of a street, like a streetlight], you just need them on the bookends, pointing at each other," Lum said. "At some point you're going to have to go to the corners" for a millimeter-wave mobile network.

3 – Most sites only had one 5G antenna.

Lum said that most of the streetlights with Verizon's equipment only had one antenna, and none of them had equipment for 4G LTE. Lum explained that this is noteworthy because it likely indicates Verizon is only blasting 5G service from that streetlight toward a specific set of customers.

Why? Well, most modern cellular antennas have a 90-degree or 120-degree field of coverage. Meaning, if you want to cover everything around a tower site, you need to install three or four different antennas, each covering a different part of the circle. Since most of Verizon's sites only had one antenna, that means the company is blasting its signal toward a specific area or group of buildings, rather than everything around that site.

Lum said he saw a few sites with two antennas, but none with more than that.

Part of the issue, Lum said, may be due to the sheer weight a streetlight can handle. After all, Verizon and the city of Sacramento probably don't want streetlights falling over because they're too top-heavy with 5G equipment.

What this all means for mobile 5G

"This is not what I expected," Lum said.

Instead of a city covered with 5G signals, and a network geared for mobile services, Lum said he instead found select locations in Sacramento where Verizon built a network that seems exclusively designed to offer fixed wireless services to a handful of potential customers.

Basically, Lum's big takeaway from his work is that, if Verizon wants to cover all of Sacramento with mobile 5G at 28GHz, "you're talking about a crapload of poles."

"I don't think there's enough people in the industry to deploy these," Lum added, noting that antennas would need to be installed every 1,000 feet or so, and each would need the requisite permits, power, backhaul and technicians capable of doing the work. And that labor would have to be replicated at each street corner across Sacramento and, ultimately, across every major and minor city in the country. "I think there's a long way to go," Lum concluded, estimating a ten-year buildout timeline for such an endeavor.

But, according to the executives at Crown Castle, that's exactly what some carriers are ordering. Tower company Crown Castle has made a major bet on small cells, and has deployed thousands of the gadgets in recent years. During the company's most recent quarterly earnings conference call with investors, Crown Castle CEO Jay Brown said that the company typically designs its deployments to account for two small cells per mile -- but he said in dense urban areas that count can increase to six or ten small cells per mile, or roughly one every 500 feet.

Although Verizon has not yet disclosed its mobile 5G buildout plans, the company may well take a page from T-Mobile and AT&T's playbook by using its lower spectrum bands like 700MHz in addition to its millimeter-wave spectrum bands. T-Mobile, for example, has said it will use its 600MHz spectrum for nationwide mobile 5G coverage, while retaining its millimeter-wave spectrum holdings for hotspots of high-speed 5G service in dense urban areas.

Finally, it's probably worth noting here that Verizon has made it clear that it is not planning to build any more 5G sites using its 5GTF standard. Instead, the company is waiting for suitable 3GPP 5G NR equipment to become available, and will then begin expanding its 5G Home coverage area to an eventual 30 million households. The company also plans to replace its existing 5GTF sites with 3GPP 5G NR equipment. That may explain its relatively sparse 5GTF buildout in Sacramento. (See Verizon CFO Reiterates Plans to Pass 30 Million Homes With 5G.)

 Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano