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State of the Stadium Network, 2018: Smooth sailing right now but rough waters ahead?

Here at Mobile Sports Report we used to have a yearly survey (called “State of the Stadium”) which we used mainly to see if and when wireless networks were being deployed in large sports venues. After just a few years, it quickly became apparent that for almost all the respondents we heard from, the question was no longer “if” networks would be deployed, but just “when.” And for more than most, the “when” was happening already.

Looking back over the past year or so of our stadium profile visits, it’s clear that the still-young market of large-venue wireless connectivity has reached a certain level of maturity, especially when it comes to well-funded deployments of Wi-Fi and cellular distributed antenna system (DAS) networks. Where in the recent past the San Francisco 49ers’ Levi’s Stadium was a groundbreaker with its extensive wireless coverage when it opened in 2014, such networks have now become the standard expectation for new venues like the Sacramento Kings’ Golden 1 Center, U.S. Bank Stadium in Minneapolis, Mercedes-Benz Stadium in Atlanta, T-Mobile Arena in Las Vegas and even in many “Tier 2” stadiums like Colorado State University’s new football stadium.

Similar high-quality networks are also finding their way into older stadiums as those venues get networking for the first time or revamp their initial outlays. Over the past couple years we’ve seen new networks appear in old venues like Notre Dame Stadium, SAP Center in San Jose and more recently, the Alamodome. Other venues that led the initial charge toward wireless networks for fans, like the New England Patriots’ Gillette Stadium, the Bank of America Stadium in Charlotte and Lincoln Financial Field in Philadelphia, all had recent upgrades to their wireless infrastructures as the venues smartly stayed in tune with the ever-increasing demands of fans and their mobile devices. And then there are pioneers like AT&T Park and AT&T Stadium, which have always managed to lead the way in finding new ways to keep their connectivity at state of the art levels.

What really helps point to a certain level of maturity is the different methods and manufacturers who all have figured out their own ways to get things done. Wi-Fi antenna deployments placed under seats, in railing mounts or overhead have all proven themselves in numerous live tests; DAS deployments have shown similar successes in a somewhat corresponding number of techniques and equipment usages; in all, there seems to be well more than one path to a successful wireless infrastructure. But before we start taking networking for granted as a commodity like electricity or plumbing, it’s a good time to remember that unlike those two services, networking doesn’t stand still. As new end-user devices and the apps they run continue to drive growth in demand, the question now is whether current Wi-Fi and DAS networks for venues will be able to keep up, or whether new technology is needed.

The need for more wireless spectrum

Editor’s note: This profile is an excerpt from our latest STADIUM TECH REPORT issue for Spring 2018, which includes a look at Wi-Fi performance during the Final Four, a recap of wireless performance at Super Bowl 52, a profile of new venue construction in Los Angeles and more! DOWNLOAD YOUR FREE COPY right now from our site!

In a previous lifetime as a cellular systems analyst, yours truly wrote a long research paper about the importance of spectrum, predicting that at some point the leading wireless carriers, namely AT&T and Verizon Wireless, were going to need new bands to expand their services. While there have been some technological tweaks to find more capacity than originally thought in the 4G LTE space, on the cellular front the march to so-called “5G” systems is well underway, with the predictable problem of marketing promises being far out ahead of usable reality.

While we’ll save an in-depth look at 5G for another point in time, it’s useful to notice that all the large wireless carriers are already making 5G announcements, of 5G trials, of 5G local networks and other assorted claims of leadership. While nobody really knows exactly what 5G is for sure, what is known is that to get to the faster/better claims being staked there is going to be new spectrum in play for 5G services, and some of it may work better than others for use inside venues.

What’s clearly not known at all is how 5G services will arrive for sports stadiums, as in whether or not they will fit inside the current DAS model. Will carriers be able to share 5G systems like they do now on neutral-host DAS deployments? Right now that’s doubtful given that carriers like Sprint and T-Mobile are already talking about 5G deployments on much different spectrum spaces — and if the proposed merger between the two carriers becomes reality, how does that further change the 5G planning landscape? Perhaps the only thing we can be sure of is a lot of mixed messages in the near future about the best way to move forward from a cellular perspective.

Will carriers take over unlicensed bands?

On the Wi-Fi side of things, a smart friend of ours once claimed that when it came to Wi-Fi network deployments, “real estate is the new spectrum” since building owners could pretty much stake a free claim to the unlicensed spectrum spaces within their walls.

But now, there may be some storm clouds brewing as carriers seek to implement systems that let them use some of the 5 GHz unlicensed channels for LTE networks, an idea with possible consequences for current venue networks.

Aruba’s Chuck Lukaszewski wrote about this issue for Mobile Sports Report last summer, and some of his points bear repeating and remembering, especially these two: One, most Wi-Fi networks in large stadiums are already “spectrum constrained,” meaning that they need all the channels in the unlicensed band to ensure good service across an entire venue; Two, by introducing a system where cellular providers would use a chunk of that spectrum for LTE networks, the effects are as yet unknown — and venue operators would most likely be at the mercy of carriers to both acknowledge and comply with any possible conflicts that might arise.

As we here at Mobile Sports Report are cynics of the first order, our first question in this matter is about whether or not there are any clauses in those contracts venues have signed with carriers that will allow the cellular providers to “share” spectrum in the Wi-Fi space as well. While Verizon, AT&T and other service providers have paid quite a few dollars to support many stadium systems, it’s worth it to wonder if some of those deals may not look so good going forward if they include the legal ability for carriers to poach spectrum currently used only by Wi-Fi.

CBRS to the rescue?

Another technology/spectrum space we’ll be looking at more closely in the near future is the Citizens Broadband Radio Service, which sits at the 3.5 GHz space in the electromagnetic spectrum roster. Though new FCC rules on the use of this spectrum (currently used primarily by the U.S. Navy) haven’t yet been solidified, it seems from all signals that eventually what will emerge is a kind of tiered licensing type of situation with licenses that cover large, small or even local geographic areas, which may allow for building owners to set up private networks that work sort of like Wi-Fi does now.

One attractive option being touted is “private” LTE networks, where venue or building owners could build their own DAS-like LTE network infrastructure for CBRS spectrum, then rent out space to carriers or run their own networks like Wi-Fi but with LTE technology instead.

What’s unknown is exactly how the licensing scheme will shake out and whether or not big carriers will be able to dominate the space; here it’s helpful to remember that big wireless carriers typically spend millions in lobbying fees to influence decisions in places like the FCC, and venue owners spend… nothing. Verizon recently announced it expects to have CBRS-ready devices working before the end of this calendar year, so it’s likely that CBRS systems may be more of an immediate concern (or opportunity) for venues than 5G. And the marketing folks behind CBRS are on full speed ahead hype mode, even crafting a marketing name called “OnGo” as an easier-to-sell label than the geeky “CBRS.” So buyer beware.

Already, Mobile Sports Report has heard chatter from folks who are helping design networks for greenfield operations that the choices simply aren’t as clear as they were recently, when you could pretty much count on Wi-Fi and DAS to meet whatever wireless needs there were. While that duo may still be able to get the job done for the near future, looking farther ahead the direction is much less clear and the sailing no doubt much less smooth. Here at MSR, we’ll do our best to help batten the hatches and give as much clear guidance as we can. At the very least, it should be an interesting trip.

Ready or not, Unlicensed LTE is here. What should your venue do?

The entry concourse at Atlanta’s new Mercedes-Benz Stadium. Credit all photos: Paul Kapustka, MSR (click on any photo for a larger image)

By Chuck Lukaszewski, Aruba Networks, a Hewlett Packard Enterprise company

There’s much excitement around the coming of “unlicensed LTE” and for good reason. In our anytime, anywhere world the last device many of us use at night, and the first one we pick up in the morning, is a mobile phone, tablet or computer. Although much of the time our devices connect via Wi-Fi, when we’re in transit we depend on cellular.

With consumers quick to express their disappointment when their apps fail to respond – or don’t respond fast enough – on a wireless network, cellular providers are keenly aware they must keep pace with rapidly escalating user experience expectations. Research suggests mobile data traffic will grow by 47 percent annually through 2021. Combine the two and the drivers for expanding network capacity are clear.

While the lure of more bandwidth can be attractive, stadium and venue operators need to carefully evaluate the technological impact and operational overhead unlicensed LTE introduces.

Gigabit cellular coming soon

Editor’s note: This post is part of Mobile Sports Report’s new Voices of the Industry feature, in which industry representatives submit articles, commentary or other information to share with the greater stadium technology marketplace. These are NOT paid advertisements, or infomercials. See our explanation of the feature to understand how it works.

To provide gigabit speeds, the cellular industry has enhanced LTE technology to bond multiple channels together, called “carrier aggregation.” Although originally designed only to combine different licensed frequencies, it has now been extended to aggregate licensed spectrum with 5 GHz unlicensed spectrum (where Wi-Fi operates). Two competing technologies for doing so have emerged, with notable differences when deploying in high-density environments like stadiums in the U.S.

LTE-U (LTE in the Unlicensed Spectrum) is a proprietary technology, developed by the LTE-U Forum, a consortium of several cellular-related companies. It enables simultaneous operation of LTE over both licensed and unlicensed spectrum by aggregating the bands together, resulting in a performance boost. However, the way LTE-U takes control of a channel – while legal in the U.S. – is controversial and may significantly degrade performance of Wi-Fi equipment using the same channel. The Wi-Fi and cellular industries worked together to produce a coexistence test plan, but so far none of the test results for LTE-U equipment authorized by the FCC have been made public.

LAA (Licensed Assisted Access) can be thought of as the standardized version of unlicensed LTE, designed to meet European “listen-before-talk” (LBT) requirements, so it can be deployed anywhere on the planet. It was developed through the 3rd Generation Partnership Project (3GPP) worldwide standards organization, with wide participation including input from the Wi-Fi community.

DAS gear above concession stand at Coors Field

Think of LBT like the telephone party lines of yesteryear, where multiple customers share a communal phone line but only one person can use it at a time for their conversation while others wait. When there is no conversation happening on the party line and two or more people try to speak at once, other customers of the party line graciously “back off” to allow one person to go first. In cellular terms, this makes LAA a more “polite” technology than LTE-U, as it waits to transmit until a channel is clear. The back-off method it uses is compatible with Wi-Fi at least on paper, although 3GPP does not require vendors to perform or publish any kind of test results.

The Road Ahead

Of course what you want to know is how the advent of LTE-U/LAA impacts your stadium and whether to add gigabit cellular to the connectivity mix.

As a robust, stable and mature technology, Wi-Fi’s strength and ability to handle exceptional stadium data traffic loads is well established. To make informed decisions about whether to consider LTE-U/LAA technologies alongside Wi-Fi, here are five essential technical considerations.

Spectrum Availability. The unlicensed radio spectrum is comprised of 24 channels in the U.S., which is analogous to a 24-lane freeway. Until now, only Wi-Fi traffic traveled on that roadway, with many years spent developing technologies to ensure steady traffic flow, particularly in stadiums. Wi-Fi includes its own LBT solution, which helps assure data merges smoothly onto the freeway. It’s been proven at six Super Bowls plus countless other concerts and sporting events.

Most stadium Wi-Fi networks are already spectrum-constrained, meaning they are just managing to carry the existing load – much less new fan technologies like AR/VR. A large body of evidence demonstrates that stadiums and arenas need 20-24 fulltime-equivalent channels to make a 5 GHz system work (regardless of technology). These Wi-Fi networks are carefully optimized to eliminate all unnecessary transmissions.

Adding one or more LTE-U or LAA systems will reduce available capacity for Wi-Fi operations. As of this writing, there are no public technical measurements of deployed systems so the actual impact is unknown. If four separate unlicensed LTE networks are actually deployed, the impact will be even greater.

Number of LTE-U/LAA Networks Required. Visitors to your stadium likely utilize each of the four U.S. cellular operators: AT&T, Sprint, T-Mobile and Verizon. Therefore, to offer gigabit cellular connectivity, you’ll need to permit all four to deploy an LTE-U, or LAA, network. Because the technologies are so new, they lack a “neutral host” methodology, so each operator will require its own separate physical network and spectrum.

DAS gear under seating area at SunTrust Park

Compatibility with Existing DAS. Most stadiums and arenas have either separate antenna systems for each major cellular operator or a converged neutral-host DAS. Although LTE-U and LAA are intended to support “dual connectivity” to a separate macro base station (or “eNodeB”) on paper, the products currently being shipped are intended as co-located small cells that contain two paired LTE radios – one licensed and one unlicensed. Stadium operators should validate whether their DAS systems are compatible with an expansive LTE-U/LAA small cell deployment where the primary cell (or “PCell”) is the DAS and each PCell has dozens of secondary cells (or “SCells”) providing 5 GHz service.

Cost vs. Benefit. Of no small consideration is the added amount of equipment, and the costs, in a hybrid Wi-Fi/cellular situation. If every cellular operator requires a separate LAA/LTE-U overlay, this implies up to four full new sets of equipment must be deployed under seats or on handrails. For a 60,000-seat stadium at typical under-seat densities, it would only require about 850 Wi-Fi access points (APs). In contrast, for LAA/LTE-U stadium operators would need over 3,000 additional small cells– with each one requiring a sturdy waterproof housing, a 30-watt POE connection, Cat-6 cabling, conduit and, of course, a hole drilled in the concrete. Meaning, LTE-U/LAA small cell deployments would require essentially the same physical footprint for each carrier as Wi-Fi which is likely already installed and is inherently a neutral host technolgy.

Risk. It’s also critical to consider the corresponding risks of adding up to four cellular unlicensed LTE networks to your Wi-Fi environment. It took about seven years and three full generations of radio designs for Wi-Fi vendors to perfect high-capacity stadium systems whereas LTE-U/LAA equipment is only beginning to ship. In short, it may be wise to delay comingling Wi-Fi and LTE-U/LAA networks until unlicensed LTE equipment becomes proven in less mission-critical settings than your venue.

Chuck Lukaszewski is Vice President of Wireless Strategy & Standards at Aruba Networks, a Hewlett Packard Enterprise company. For over a decade he has engineered and deployed large-scale 802.11 networks, joining Aruba in 2007.

Chuck has built Wi-Fi systems in stadiums, seaports, rail yards, manufacturing plants and other complex RF environments, including serving as chief engineer for many stadiums ranging from 20,000 to 100,000 seats that provide live video and other online amenities. He is the author of six books and design guides including Very High Density 802.11ac Networks and Outdoor MIMO Wireless Networks.