While taking a walk down San Francisco’s central Market Street, Verizon executive director Phillip French highlighted the improvements that the cellular provider has made to its network to prepare for the upcoming Super Bowl.

Though they are largely hidden from view, Verizon has installed 75 small cells in the Bay Area, including 46 just in San Francisco. The units, far smaller than traditional cell towers, sit behind traffic signs, inside magazine kiosks and atop poles. The company has also added 15 traditional cellphone towers, including 10 in San Francisco.

Forty miles south of the city, behind a nondescript building in Sunnyvale, Verizon has set up a pair of bungalows where engineers monitor its network performance throughout the Bay Area. It has screens showing what’s going on in and around Levi’s Stadium in Santa Clara, as well as back in San Francisco, at the Super Bowl City event for which it is the lead sponsor. In another room, an operations team is monitoring the physical condition of gear, ready to dispatch repair crews placed at the ready.

AT&T has a war room of its own, located within Levi’s Stadium, where employees will be monitoring the network.

“On game day, when most people are sitting on a couch, or the lucky ones are in the stadium, we are going to have folks in the bowels of the stadium,” said AT&T assistant VP John Cooke, who oversees the company’s network engineering for the San Francisco Bay Area.

It’s all in preparation for Sunday’s big game in Santa Clara, as well as the accompanying parties and celebrations taking place this week throughout the Bay Area, where more than a million people are expected to attend various festivities.

Obviously, that creates demand well in excess of already heavy cellphone use. Plus, unlike traditional cell traffic, which is heavily weighted toward downloads, Super Bowl-related traffic features nearly as much data being uploaded, as people send videos, selfies and social media updates to show all their friends what they are missing.

AT&T says it has recently invested $100 million in upgrades in the Bay Area, a quarter of which were specifically tied to expected Super Bowl traffic. The carrier installed six new cell sites around Levi’s Stadium and has brought in nine so-called COWs, or cell-on-wheels, to serve areas like Super Bowl City, the stadium parking lot and various game-related party sites. Verizon said it has spent $70 million upgrading its network above and beyond what it would have otherwise done.

While the planning started two years ago, most of the new gear has just come online in the past few months, some of it as recently as last week, French said.

T-Mobile, for its part, says it has increased capacity at local cell sites, upgraded its distributed antenna system within Levi’s Stadium and installed various temporary sites. Sprint, meanwhile, says it has 11 cell-on-wheels and has beefed up its systems at San Francisco’s Moscone Center and within Levi’s Stadium.

Verizon’s efforts, the company stressed, are almost all permanent improvements to the fast-growing Bay Area market.

“A lot of this was under way to fix San Francisco,” said French. The Bay Area has seen higher data growth than anywhere else in the West Coast area, he added. “San Francisco has just blown up.”

Verizon is in the midst of a project that has seen it already place 150 small cells in San Francisco, with plans to put in a total of 400 small cells in its current wave of upgrades.

The effort has not been without challenges, though.

“The initial design given to the city left out required equipment, which required multiple redesigns/mockups to ensure the design would be compatible next to historic buildings,” said Omar Masry, who has overseen wireless planning efforts for the city of San Francisco. “Ultimately, we found an approach that worked.”

French acknowledged that there is always a lot of back and forth when it comes to city planning, noting that the city rejected some of Verizon’s initial proposals to put small cells onto traffic lights.

Each Super Bowl location has its different needs. In downtown San Francisco, each carrier has a COW parked right along the Embarcadero to add capacity for all the tourists visiting Super Bowl City. Though the event is sponsored by Verizon, each carrier will have plenty of its own customers looking to post photos and videos.

At Moscone Center, the NFL Experience features the Vince Lombardi Trophy and a collection of Super Bowl Rings, and is expected to draw crowds comparable to business conferences like Oracle OpenWorld and Salesforce’s Dreamforce, which typically occupy the convention center. “I think both those events prepared us,” French said.

Come game day, Verizon expects to have 80 people in those bungalows from the network team alone, along with others that support business, technical support and other functions, plus representatives of its main contractors. Workers are also being put up in hotels, since Verizon needs them to work long shifts, and many can’t afford to live in prime Bay Area spots; instead, they commute long distances from outposts like Stockton, which is 80 miles from San Francisco. Meals will be catered, and the pantry was stocked with snacks before the first workers arrived.

“You’ve got to keep them happy,” French said, tapping a large freezer that has been brought in to store ice cream treats.