While Donald Trump only had about two months to prepare to take the highest office in the land, engineers have been getting ready for the moment for two years. Each of the country’s four largest wireless carriers have upgraded their permanent cell infrastructure surrounding the National Mall and are bringing mobile reinforcements for inauguration weekend, fortifying the area to handle an onslaught of selfies and live streaming.

“We’re expecting a massive amount of data usage,” says Mark Funka, Verizon’s lead engineer for inauguration planning. He likened the physical span of the activities to “four Super Bowls all put together,” with perhaps ten times the number of people as football’s biggest event.

When a record-setting crowd came out to see President Barack Obama take the oath of office the first time, Apple was only on the second generation of the iPhone. Four years later, less than half the American population owned a smartphone. Though the phones of 2009 and 2012 were capable of only a fraction of what today’s devices can do, attendees at both inaugurations still frequently found their calls and data usage stymied by poor service. This time around, wireless companies believe they are well-prepared.

“A lot of work has gone on to make sure that all the assets we can physically put out there, are out there and optimized,” according to Brian Harrison, AT&T’s lead engineer for the effort. The company says it has poured $15 million into the plans, with the end result that capacity is up more than 400 percent.

AT&T, Sprint, T-Mobile, and Verizon are all bringing in cell sites on wheels, known as COWs, to provide additional capacity on the Mall and, in some cases, around the parade route. Engineers with AT&T and Verizon each touted new technologies embedded in their COWs that drastically expand capacity from what a regular mobile antenna can handle, essentially by dividing the service area into wedges.

All four carriers also said they have upgraded the permanent LTE infrastructure downtown and at other sites in the District—a boon for Washingtonians even after the crowds disperse.

Verizon says its network capacity is up by 500 percent throughout the city; T-Mobile says the upgrades it has made around the National Mall in the past year have boosted its 4G LTE capacity by nearly 1,000 percent; and Sprint says it has doubled capacity at cell sites around Metro stations and the Mall.

Even on a regular day, cell carriers already handle a tremendous amount of traffic on the nation’s front lawn—which sees around 25 million visitors a year. Verizon, for example, handles about 23 GB of data every 10 minutes around the Mall, according to Funka.

He declined to give an estimate of what kind of data usage they’ll see on inauguration day and during the Women’s March, which are expected to draw upwards of 800,000 and 200,000 people respectively. With cellphone usage ranging from texting to data-heavy streaming and simulcasting, “it is difficult to gauge what will happen. But we are built to support a tremendous amount of data,” he says, adding that the company made its preparations based on estimates of between 1 million and 1.8 million people.

Despite all the upgrades and temporary reinforcements, service in such a large crowd isn’t always a guarantee. If everyone in a particular area decides to get on Facebook Live at the same time, for example, it’s going to create problems. Should an attendee find themselves having trouble with cell service, experts recommend text messaging instead of calling if they need to reach someone.

“At the end of the day, it’s very difficult to say 100 percent that its going to work perfectly everywhere,” Harrison says. “But we feel really good about the plan we’ve laid out.”