UPDATE: Since writing this Thursday, I have heard from Eagles fans who say the team's wireless seems still a work in progress; they have been unable to access Eagles media through the stadium Wi-Fi service. What is your experience? JoeD@phillynews.com.

EARLIER: "This is one of the most connected facilities in the NFL, with the highest levels of fan engagement on game-day (smartphone and iPad) apps," says Charles W. Berger, pointing to wireless switches embedded high above his head in the stands at Lincoln Financial Field, the 12-year-old Philadelphia city stadium where the Eagles play.

Berger, a Willow Grove native, is chief executive officer of Extreme Networks, a San Jose-based,ha $600 million yearly-sales company whose predecessor, Enterasys, built the Eagles' free wi-fi system last season with project manager PCM Inc. "They put in 30 miles of cable in 90 days, building a bridge to our fans," says Anne Gordon, the Eagles vice president who oversees digital media and other communications (and an ex-Inquirer managing editor).

For this season, Extreme Networks doubled the Eagles system's capacity, to 2 gigabytes of bandwidth, enough to handle high call volume in the 69,000-seat stadium. The idea is to avoid the kind of system crashes that Berger says he's suffered in West Coast stadiums crammed with smartphone and iPad users who on occasion overloaded aging cellular connections.

Extreme Networks, which competes with industry leader Cisco Systems, has connected 10 NFL stadiums; that gives the company data on fans' digital behavior for all 32 teams as they move around the league.

Berger says he plans to add NBA and NHL venues soon, though Major League Baseball, which celebrates retro stadiums and the old-time fan experience, has been slower to sign on. The company's other wi-fi clients include West Coast schools, which are experimenting with remote teaching, and hospitals that offer apps like wireless patient monitoring and emergency-room waiting-time advisories.

Berger was in Philadelphia Wednesday to speak at an Eagles Mobility Summit that also attracted National Football League officials, including chief information officer Michelle McKenna Doyle. He said Eagles President Don Smolenski set a high priority on digital "fan engagement," which Gordon said flowed from owner Jeff Lurie's "progressive" focus on the future. It fell to John Pawling, the Eagle's info tech chief, to make it happen.

"We also have a strong relationship with Comcast, which brings Internet into the building," said Extreme Networks' senior vice president, Norman Rice, who joined the company when it bought his former employer, Enterasys, last year.

The faster system makes it easier for fans to run Eagles instant-replays and videos from the many cameras built into the stadium -- of players pumping themselves up in the tunnels beneath the stands, for example -- through custom apps built for the team by Pittsburgh-based YinzCam.

"The Eagles do an unusually strong job promoting this with their fans," says Extreme Networks' Rice. "They want to engage their fans to watch the game, and also that second screen, and to see their photos on the Jumbotron."

The Eagles are pushing so many digital pictures, videos and offers through their apps that Lincoln is the only NFL stadium where fans download more of the team's digital content than they upload from their own smartphone snaps, according to Extreme Networks data.

One-third of Eagles fans use the team's apps at Lincoln games, up 22 percent from last year, and a higher rate than for any other team, says Gordon, citing the same data.

Pro sports, with its aging fan base -- the average fan for many pro teams is approaching 50 -- struggles to attract younger viewers, many of whom are not used to sitting through any event three hours long. Teams are also trying to juice the stadium experience, to keep older season ticket holders from staying home next season "with their 60-inch screens they can freeze when the go to the bathroom, and all the (cable-service) enhancements," says Berger.

Eagles executives had asked if the team's aging fan base would use wi-fi enough to justify the cost of upgrades. Gordon says that question was answered when fans at the Redskins game in September uploaded and downloaded more content than the teenaged audience at the sold-out One Direction concert at the stadium four weeks earlier. "Our season ticket members are using their phones and tablets just like everyone else," she said.

Gordon says YinzCam, which has developed apps for more than half the NFL teams, has taken to rolling out beta versions of its apps in Philadelphia before taking them to other NFL cities.

When the Eagles rolled out their apps, the team depoloyed a group of "wifi coaches" who roamed the stands helping fans use the apps, says Rice, who ranks the city with tech-crazed San Francisco as an early adopter of digital football enhancements. The job has since been absorbed by the generalist "team ambassadors" who assist fans.

Gordon wants more and "richer" apps for next season. The use of wi-fi in pro sports is just getting started, says Extreme Networks' Berger. He notes that the referees at a recent Rugby 7s championship "ran around wearing Google Glass so fans could see (through Glass-mounted cameras) what the ref was seeing."

That enables a  level of second-guessing that still remains mostly off-limits to pro sports fans. So far.

Why do the Eagles bother? Like a majority of NFL teams, they sell out season tickets and fill the stadium for all eight home games. Eagles officials I talked to couldn't say the electronics has measurably increased fan interest.

Gordon says the point is keeping today's fan interest high. "Everyone here wants to be mindful of what the season ticket members want to see and how we can move this forward," she told me. "We are not driven to sell tickets. That frees us to serve the fans at a very high level." (Revised)