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Pope Francis‘ visit to D.C. this week has already prompted the federal government to recommend letting its employees work from home, as if the District were to receive three days of snow. But phone companies are also bracing for the pontiff’s stay through Thursday, given the amount of mobile activity they’re expecting from the crowds following him.

Enter the COW, or Cell On Wheels—a multi-beam antenna apparatus that will expand wireless-network capacity during the papal visit. AT&T is installing three COWs near the pope’s major public events: one near the Basilica of the National Shrine of the Immaculate Conception, where Pope Francis will conduct a canonization mass on Wednesday for Junípero Serra, a Franciscan friar active in California during the 18th century; a second near the White House, where the popemobile will parade on Wednesday; and a third near the U.S. Capitol, where the pope will deliver remarks to a joint session of Congress on Thursday. Those COWs will expand capacity by 1,500, 600, and 1,000 percent, respectively. The first is actually a “super COW,” measuring 150 feet tall and costing more than $100,000, according to company engineers, which is necessary to accommodate the 25,000-plus faithful expected at the outdoor canonization mass.

“If everyone decided to upload a video of the pope at one time, that creates huge demand,” says Lawrence McWright, director of radio-access network engineering at AT&T. “If you didn’t have [a COW] set up, you wouldn’t necessarily be able to make a phone call, couldn’t go on Facebook, Twitter, Instagram, [and] you wouldn’t be able to send pictures through messages. You’d also have a host of coordination issues, like trying to meet up with friends and family.”

Brian Harrison, a technical communications manager at AT&T, adds that COWs have been in operation for the past few years—a response to increased data-demand from users. From 2007 to 2014, mobile traffic on the company’s network jumped a whopping 100,000 percent. AT&T has used them during the Super Bowl, the president’s inauguration, and the Cherry Blossom Festival.

Both say the company has been working closely with the Department of Homeland Security, the White House, and other agencies to make sure communications during the pope’s visit are stable. Washington Business Journal reports that Verizon is undertaking similar measures for its users.

“The reality is we can handle a lot of bandwidth, a lot of data,” McWright explains. “It’s just when everyone decides to use something like video at the same time, you start to see some pressure. Now if 70,000 or 80,000 show up [to the pope’s mass], we’ll have a little pressure.”

Here’s what AT&T counsels if you plan to join the crowds and follow the pope on his journey:

  • “With all large, high-traffic events, we suggest texting rather than calling since it’s easier for texts to cross the network
  • Take advantage of Wi-Fi hotspots when possible. This eases pressure on the network.
  • If you can, wait until you have access to Wi-Fi or are not in a crowded area to send pictures or post to Instagram.
  • Make sure your phone is charged.
  • You might even consider bringing a power bank to boost your phone or other devices.”

Photos courtesy of AT&T.