Modernising the Bridge: Why Chelsea have become the first Premier League club to enable a 5G stadium

Chelsea’s Stamford Bridge home is one of the most famous stadiums in English soccer. It originally started life as an athletics ground before Chelsea arrived in 1905 and has hosted FA Cup finals, England internationals and even greyhound racing.

Since the beginning of the 21st century, the stadium’s international reputation has grown in stature with that of the club, with Roman Abramovich’s 2003 takeover a precursor to an era of unparalleled success.

The club’s fanbase has grown significantly, and Chelsea now have little difficulty in selling out Stamford Bridge for most games. However, the venue’s official capacity of 41,837 is only the ninth largest in the Premier League and is dwarfed in size by the homes of its domestic and European rivals.

The last major wave of construction occurred in the late 1990s and further expansion is prevented by a lack of space as the site is enclosed by railway lines, busy roads, and other buildings. With ambitious plans for a 60,000-seater arena on hold for the foreseeable future, it is likely that the capacity and dimensions of Stamford Bridge will remain static for many years to come.

If expansion is off the table, then modernisation certainly isn’t. Loyal fans will still come through the turnstiles week after week, but both soccer and London are competitive environments and facilities must be updated to attract new fans, hospitality customers and other events. There is also a growing recognition that venues need to be able to offer many aspects of the armchair experience or else certain sections of supporters might stay at home.

Stamford Bridge first opened its doors in 1877 and Chelsea FC arrived in 1905

This helps explain why Chelsea were so keen to improve mobile coverage at Stamford Bridge. With the help of mobile operator Three, also the club’s principal shirt sponsor, they have become the first Premier League side to roll out 5G across their entire stadium.

For some supporters, attending a sporting event is no longer about turning up five minutes before kick-off, taking a seat and then leaving as quickly as possible. The matchday experience is becoming increasingly important and mobile connectivity is an essential part of that, allowing fans to access live scores, watch video highlights and interact with social media.

The problem is that it has traditionally been very difficult to equip vast sporting arenas with reliable mobile coverage. Stadiums are generally complex network environments, characterised by concrete bowls that are difficult for mobile signals to penetrate, with tens of thousands of people all competing for signal. Meanwhile, higher levels of smartphone ownership coupled with ever more bandwidth-intensive applications are exacerbating the situation.

Stamford Bridge was no exception, as Three’s senior radio access network (RAN) solutions manager Brett Rogers tells SportsPro: “You had 42,000 people [using the same cell] as well as the rest of the people in the [surrounding area]. The network on a matchday would be completely saturated so there would be no user experience in the stadium and no signal for the people in their homes.”

Why 5G is different

5G addresses many of these issues. It is a far more efficient mobile technology, meaning it offers significant speed and capacity advantages over 3G and 4G, while the backend (known as the core) is designed in a completely different way so data is sent across the network much more rapidly, reducing latency. 5G will also be much denser and use a much more diverse range of frequencies, improving indoor coverage and boosting reliability.

These characteristics will improve mobile services for anyone in the stadium, even those using 4G smartphones, and allow Chelsea to roll out new services that engage fans in their seats. This might be an augmented reality (AR) application that overlays statistics such as speed, shots on target, distance covered, and passing data in real-time or a video service that offers multiple angles and instant replays. Both of these examples demonstrate the benefit of 5G’s faster speeds and lower latency.

Three started work on installing the network at Stamford Bridge during preseason. Although there were no matches or spectators in the stands to contend with, the club were less keen on the network team using cherry pickers on the freshly relaid pitch to install the radio equipment. This meant engineers abseiled down from the roof instead.

The age of Stamford Bridge also affected deployment. When Chelsea opened the East Stand back in 1973, it was a state-of-the-art stand, eschewing supporting posts in favour of a cantilever structure that offered anyone sitting in it an unobstructed view of the pitch.

There’s a lot of stuff [on the roof] that’s been there for 20 to 30 years so finding space to hang the equipment was a challenge.

Brett Rogers, Senior RAN Solutions manager, Three

However, even the more modern stands that date back to the late 1990s were designed for another era, one in which connectivity was nowhere near as important as it is today. While Tottenham Hotspur could bake a futureproof fixed network into the design of their new stadium, Three’s network team had to find physical space to host their radio gear, such as antennas. Meanwhile, Three spent plenty of time “ripping up” ceilings to install the fibre network that supports the equipment.

“It was a typical stadium deployment but because of the age of the structures we’re still moving some of the antennas,” Rogers explained. “There’s a lot of stuff [on the roof] that’s been there for 20 to 30 years so finding space to hang the equipment was a challenge.

“The build took around two months, and we did one stand at a time, working around game times to rig those antennas and optimise them. It was probably two to three weeks for each stand and back of house, it was just a prolonged period lasting about two months to run the cable round.

“The club have been brilliant. They’ve supported us every step of the way, facilitated access and their teams and our teams work together [closely]. They’ve bent over backwards to help us.”

Mobile phone equipment hangs from the stadium roof

A soccer innovator

In technical terms, Three has replaced a legacy distributed antenna system (DAS), a technology which spread the total network capability across multiple antennas instead of just a single access point, with 34 DAS ‘sectors’ that offer speeds of up to 250Mbps. Even customers with 4G phones will benefit because these networks share much of the same infrastructure.

“It’s a nice, clean signal that can repeat around the stadium in 34 sectors,” said Rogers, who adds that it’s far more efficient than the old system because Three has its own equipment in the venue.

Inside the stadium itself, Three has deployed 133 ‘picocells’, a very small mobile base station, on the ceiling of every floor. This improves indoor coverage in all public spaces and in the dressing rooms. This obviously benefits social media-savvy players but can also improve performance. Many clubs now make use of cloud-based analytics software that can send insights and video packages to players to watch on their own device, while tablets are a common sight on the touchline among coaches.

“You have seamless coverage wherever you are in the stadium,” added Rogers. “Traditionally this would be hard to do with a [traditional network mode] because of the concrete.”

Three intends to go even further. It has already installed microsites around the perimeter of the stadium so residents don’t lose connectivity on a matchday, and Stamford Bridge is now one of Three’s most important sites in the Fulham Broadway area. Meanwhile, there are also plans to connect Chelsea’s Cobham training ground and Kingsmeadow stadium in Kingston, the home of Chelsea Women.

Ultimately, Three hopes the stadium will be a testbed for future network innovations and demonstrates to other venue operators and businesses what its engineers are capable of doing in such a challenging environment.

But for now, Three has a very happy customer.

“What Three has achieved here at Stamford Bridge is ground-breaking and a testament to the strength of its 5G network,” said Chelsea chief executive Guy Laurence, who knows a thing or two about mobile networks having previously been in charge of another operator, Vodafone UK. “The possibilities of how we can enhance the fan and stadium experience are endless and our team is excited that it is now live.

“Staying connected is essential for fans and mobile has become an integral part of matchdays. 5G enables us to begin to merge the physical and digital for ultimate fan experiences. With Three beside us, we will be able to deliver the next generation of connected entertainment and continue our quest to be one of the most innovative clubs in world soccer.”