WASHINGTON — Teresa Davidson of Des Moines, Iowa, will be using her smart phone to tweet, snap pictures, record video and send it all out to friends, family and coworkers during President Barack Obama’s second inauguration Monday. Davidson said it’s a big change from the 2009 inauguration, when she hardly used any social media to record her experience at the National Mall.

Davidson will be one of the many spectators using smart phones during the inauguration. The impending influx of wireless users has major cell phone providers spending hundreds of millions of dollars, in the case of AT&T, to reinforce the network and keep the crowd’s tweets, updates, texts and phone calls flowing freely from the Mall.

“Our planning for this inauguration started day one after the last inauguration,” said Melanie Ortel, a spokeswoman for Verizon.

Ortel would not give a ballpark estimation of the cost for developing the wireless network since the last inauguration, but said investments have been “extremely significant.”

AT&T invested about $815 million on permanent upgrades in D.C. since 2009, but that doesn’t include the mass of temporary infrastructure put in place for cell phone use during the ceremony, said Mark Siegel, AT&T’s executive director of media relations.

A temporary communications tower on the north side of the National Mall. (Robert R. Denton)

For this inauguration, Siegel said AT&T is bringing in nine cellular towers on wheels, known as COWS, to boost signal, and more than 60 free Wi-Fi hotspots. The company is also installing antenna amplifiers and extra copper and fiber to improve cell site transmission. They will also be adding new, temporary antennas along the parade route.

 Siegel said the best plan for inauguration attendees is to use the Internet at one of the many Wi-Fi areas set up around the National Mall. That will save room for phone calls and texts on the wireless network.

 Even with all those improvements, cell phone-using inauguration-goers could still experience lag and signal problems, Siegel said.

“Any wireless carrier is going to tell you it’s going to be a challenge when you have hundreds of thousands of people in a limited area getting on their smart phones,” he said.

The crowd is estimated to be anywhere from 600,000 to 800,000. That’s down from 1.8 million estimated to have attended Obama’s first inauguration. Nevertheless, the crowd will use more network capacity than in 2009 due to the prevalence of what Siegel calls “small, powerful computers in people’s pockets.”

A lot of what people are doing with their phones, including taking video and photos and using the Internet, is driven by social media.

Davidson says her social media use “has increased 200 percent since the last inauguration.”

Social media was a different beast in 2009. Facebook only had about 400 million users — it now has more than 1 billion. Twitter had five million users sending two million tweets per day; today, that many tweets are sent every 10 minutes, says Twitter spokeswoman Elaine Filadelfo. Pinterest was just a glimmer in the creative minds of its makers.

 Similarly, Obama’s first inauguration was a different time in the fast-evolving world of cell phones. Back then, Steve Jobs was touting the 16-gigabyte iPhone 3G. Droid 2.0 was Motorola’s newest operating system..

 The increased capabilities are a welcome change for Davidson, who now has a Twitter and Facebook account. She worked for both of Obama’s campaigns and is attending this inauguration with her daughter, Angie, who lives in Denver. Davidson is an eighth grade American history teacher at Norwalk School in Des Moines.

 “I will be tweeting and the Des Moines Register will be following me,” Davidson said. “It will mean a lot to my students.”

By David Barer