What do you get when you take a 1.85 million sq. ft., 70,000 seat NFL stadium and cram it full of screaming fans? An incredibly challenging Wi-Fi environment would be an understatement. It doesn’t even begin to describe what engineers were dealing with when tasked with creating the foundation for the most technologically advanced stadium in the NFL. In order for everything to work, the mobile app, concession ordering system, location services, everything needed to be perfect.
Levi’s Stadium in Santa Clara, Ca, with a cost estimated to be approaching $1.3 billion and a construction time of just over 2 years, is the newest stadium in the NFL and home to the San Francisco 49ers. They set out to create a venue centered around the fan experience and have just set the gold standard by which all others will be judged. In fact, it may have set the standard for all public venues. In order to achieve this the team in charge made use of existing technologies stretched to their conceivable limits and incorporated some new tech to accomplish some pretty amazing feats of engineering.
First, let me take you back to February of 2014 when I attended a presentation at the Wireless LAN Professionals Conference (WLPC) in Austin, Tx where Chuck Lukaszewski discussed engineering in high density environments. He had a small case study on the soon-to-be-completed stadium towards the end where he talked a bit about the design and difficulties faced. The presentation was recorded and is available online (Levi’s Stadium case study starts at 52:00). In there he goes over the antenna positioning, segmentation of coverage areas, and the thought process behind it all. Of course, that was all before the stadium went live. As any wireless engineer knows, predictive models and sample surveys aren’t exactly representative of how a dense install will act in real life. That’s especially true when you go from an empty construction site to Monday Night Football. Even with all the effort put into the design, it was hard to predict how the highest density football stadium installation to date was going to perform. I know I wasn't the only one in the room waiting to see how it all turned out.
Fast forward to this past Sunday when I flew up to Santa Clara to attend a game at the stadium with a few friends from Aruba and the Airheads community. As much as I love a good football game, I was probably one of three or four people in the stadium less concerned about the Redskins and more concerned with seeing if and how the whole thing worked. Chief Airhead (I know him more from his former Wireless Field Day delegate life) Sean Rynearson was able to arrange a tour of the facilities and an overview of the operations led by Chuck himself.
First of all, you should know exactly what was trying to be accomplished. The 49ers were planning on integrating a slew of technology to not just provide information but fully engage with fans and enhance the entire experience. For maximum fan adoption and usability they built a mobile app that would be integral to providing that experience (because who doesn’t have a smartphone these days?). The features of their new app had to get people to do more than download it and take a peek before and after the game, they need people to use it throughout the whole game. Some of the notable ways they’ve guaranteed adoption by fans are in-seat concession orders (either for pickup at the closest stand or delivery right to your seat), waypoints and indoor navigation (which exceeded my expectations), live game coverage and stats, and streaming media from instant replays to old footage. They also knew that fans want to share what’s going on with the outside world so the Wi-Fi needed to be not only easy to connect and use, not only have wide coverage throughout the stadium, but it needed to be everywhere and be fast.
That afternoon we were given a high-level design overview and a look at the stats from each game so far (which provided some staggering numbers). 1,200 access points (half of those serving the lower bowl), 400 miles (70 of those dedicated to Wi-Fi) of cabling, dual 40Gb backbones serving the stadium (not just the Wi-Fi), 52 IDFs, 5 physically segmented each serving separate functions (e.g. Wi-Fi, IP TV, Office, etc), the probable world’s largest Bluetooth LE beacon deployment to date, and picocells squeezed down to each serve 80-100 seats comprised the physical aspects of the deployment. Alone that network is impressive enough but after seeing what it can accomplish when fully loaded is mind-blowing. Chuck took us through every metric you can imagine (including one Aruba had to create to create just to put a number to the scale of what was happening). During games the average concurrently active client count would hover around 15,000 devices and climb upwards of 20,000+. Additionally, starting approximately 30 minutes before kick-off the network would reach a sustained throughput of 1Gb+ and hold there until well after the final play of the game. It didn’t stop there though, the network peak throughput climbed higher and higher, holding around (and often exceeding) 3Gbps for much of the action. Layered in with the Wi-Fi, Aruba also provided the beacon deployment which was integral to the operation of the mobile app. Through the use of in-app location services powered by beacons a fan is able to navigate the stadium in real-time to any waypoint within the app, from restrooms to concessions.
I knew beforehand my biggest questions were about band usage and the experience difference between them so I brought along a single radio Windows Phone to test just that. From basic web usage and a few random speed tests it was clear the stadium was designed to accommodate newer devices supporting the 5GHz band. Although not unusable, my iPhone 6 was consistently faster and proved to be better connected. Chuck later confirmed this was by design and gave some insight into the radio trickery used to direct devices to use the more favorable frequencies… and surprisingly ClientMatch wasn’t part of it. While ClientMatch is enabled, between the radio density and some altered power levels between the two radios enough they were able to use the device’s own driver algorithms to favor 5GHz.
Connecting to the network required no sign-on, no click-through, and no registration. It was just easy. Throughout the game I used my phone quite heavily, tweeting pictures and updates. Not once did my phone struggle or my connection lag any noticeable amount. The location service was spot on and even accurate as I moved between floors with waypoint navigation proving to be a valuable feature for an out-of-towner. Overall, I couldn’t have been happier; not a single complaint. In my travels I have seen many venues offer free Wi-Fi as a way to engage with customers or simply as cellular offload with disastrous results. I applaud the team responsible for engineering the Levi’s Stadium network and hope it will be used as a blueprint moving forward on how free Wi-Fi can and should work.