Stadium Tech Report: Aruba Networks chief engineer on building the ‘ultimate stadium’ network at Levi’s

For Chuck Lukaszewski, getting the job to design the Wi-Fi network at Levi’s Stadium was a bit of a personal perfect storm: Having long desired to build the ultimate stadium Wi-Fi network, he’d finally been matched with a customer with plans and a budget to fulfill that dream.

Lukaszewski, the senior director for outdoor solutions engineering at Levi’s Wi-Fi gear supplier Aruba Networks, said the aggressive vision for connected fan engagement put forth by the San Francisco 49ers and their vice president of technology Dan Williams was a plan Lukaszewski had long wanted to pursue.

“I had a vision of how to build an ‘ultimate stadium,’ and Dan said he wanted an ultimate stadium,” said Lukaszewski in a recent phone interview. “He gave me the freedom to design something that had never really been done before. It was a real meeting of the minds.”

By early results, the joint effort is by all standards a success, with network traffic statistics from the first football game at Levi’s showing a robust Wi-Fi network with Super Bowl levels of user traffic. According to Lukaszewski, by the time kickoff rolled around for the Niners’ preseason game against the Denver Broncos on Aug. 17, the Wi-Fi network at Levi’s Stadium had already surpassed the three most recent Super Bowls when it came to concurrent network usage, and had also exceeded the peak network usage statistics from the recent World Cup finale in Brazil.

While the network still hasn’t been tested in a regular-season game, or with the planned instant-replay feature active on the Levi’s Stadium app, it’s probably safe to say that at the very least, Lukaszewski and Williams have hit the ground running successfully. And while the network team did have some factors in their favor – including the ability to blend the wireless infrastructure into the overall stadium buildout and the budget for 1,200 Wi-Fi APs – there was still significant work that had to be done to produce a wireless experience with the magnitude of Levi’s offering.

Avoiding the ‘circular firing squad of RF’ in antenna deployment

According to Lukaszewski, he’s had experience deploying Wi-Fi networks in many unusual or difficult places, including on oil tankers and on financial-market trading floors. But stadiums, he said, especially open-air arenas like football stadiums, require a much higher level of deployment expertise, especially when you are trying to provide an extremely high level of connectivity to every seat in the stadium, as the Niners wanted to do at their new 68,500-seat home in Santa Clara, Calif.

“The 49ers have a completely unique view of the connectivity experience in a stadium – it’s the whole relationship of a fan with home,” said Lukaszewski. “Technology is just one piece of that. And [wireless] connectivity, is the last yard.”

But just like that last three feet into the end zone, the last yard is often the toughest distance to cover when it comes to providing Wi-Fi connectivity. Unlike cellular operators, who own and control their licensed swath of spectrum, Wi-Fi networks operate in the unlicensed band of airwaves, and have an unknown number and type of end-user customers to support. According to Lukaszewski, designing and deploying a large-scale stadium Wi-Fi network is extremely more difficult than building a similar cellular network, mainly because of the interference situation.

“The classic design for a cellular DAS [distributed antenna system] in a stadium is to just put antennas high up, all the way around the bowl, pointing down,” said Lukaszewski. “That’s completely inefficient for Wi-Fi – we call it the ‘RF circular firing squad.’ Cellular owners can do that because they are exclusive owners of their spectrum and can bathe the bowl in signals. With Wi-Fi we have to ‘share the air’ in a ‘listen before talk’ environment.”

APs under seats, close to the fans

Without getting too deep into the specifics of Wi-Fi networking, what Lukaszewski, Williams and their teams needed to do was to figure out how many Wi-Fi access points (APs) they would need to provide high-quality connectivity to every seat in the house, and where to put them not just to provide the connection, but to also avoid interfering with signals from other close-by APs. While some of the planning can be done beforehand, Lukaszewski said that like in a restaurant kitchen, the final product often involves some hands-on refinement.

“You have a recipe, but you taste it and change it as you go,” Lukaszewski said, comparing the Levi’s deployment to a dinner dish. “We start out by going with the plan, then take a lot of data and make changes in real time.”

In the Niners’ favor was the fact that Levi’s Stadium was built from the ground up with the connectivity in mind, which made it much easier to deploy the network than in older stadiums where wiring and antennas need to be retrofitted into existing structures. Things like the many under-the-seat APs at Levi’s, with their wiring holes and mounting infrastructure designed into blueprints, might require concrete drilling and unsightly cable runs at stadiums built before networking was a pressing need.

“It’s always better when you can design it in,” said Lukaszewski of the wireless infrastructure. “The key is to have lots of low power cells, right among the people. That’s how we extract capacity. To get that you have to mount APs, and get the wiring to them. That can be very expensive in a retrofit. And it’s not always going to look very nice when you do it.”

More recipes for different events

Even with the impressive stats from the initial game, Lukaszewski was fast to note that the Levi’s Stadium wireless network is far from a finished product.

“We still have a lot of work to do – we’re definitely not done trying yet.” Lukaszewski said. “Every game, we want to get a little better.”

Typically in a stadium situation, Lukaszewski said, it may take 5 to 6 big events for the network team to really lock in on the tuning and tweaking necessary to make the network run at optimal performance. But even then, there’s still work to be done since the network requirements often differ greatly for different event types and crowds.

“There can be, more than one [network] recipe,” Luckszewski said. “The use case for a concert, for example, is way different than a football game. In an indoor stadium where you have both basketball and hockey, you may have 3 or 4 recipes, depending on the event.” Levi’s Stadium, he noted, is already scheduled to host several different types of events, including soccer games, high school football games, and an NHL game early next year.

But even as Lukaszewski, Williams and their teams continue to improve on their work, the early returns seem to suggest that the Niners have accomplished what they set out to build at their new home: A connected stadium that provides a fan experience unlike that found in most other large public venues.

“I think the 49ers have set an example for any team, in any sport,” Lukaszewski said.