There are projects that test you in a way you don't forget. Mad Cool was one of them.
Three editions. Two venues. A festival that grew faster than anyone expected. And a technical team that had to come up with solutions on the fly because, quite simply, there was no manual for what we were doing.
This article recounts enbex's first years as the Mad Cool Festival's technical partner, between 2016 and 2018. It's not a polished success story. It's a story from the trenches. Of kilometers of cable laid against the clock. Of payment terminals that needed a wired network because no one trusted WiFi for transactions. Of hundreds of access points installed in venues that changed shape every year. And of intense learning that, along with many other projects, is part of what enbex is today.
Mad Cool 2016 and 2017: The Beginnings at Caixa Mágica
Mad Cool was born in 2016 at the Caja Mágica in Madrid. Three days of festival. More than 100,000 attendees in its first edition. A lineup that included The Who, Neil Young, and The Prodigy. For a new festival, it kicked off with an ambition that made it clear they were serious.
In 2017, the second edition sold out three months in advance. Green Day, Foo Fighters, and Kings of Leon headlined a lineup that drew 135,000 people. The festival was no longer a promise. It was the mega-festival that Madrid had been waiting for for years.
enbex was there from day one. Our job was to set up all the telecommunications infrastructure for the venue. Wired network for bars, food courts, and payment points. WiFi for press, artists, and backstage. Connectivity for brand activations, sponsor booths, and the festival's internal organization. Everything that needed an internet connection to function passed through the network we set up.
When Cable Was King
Nowadays, payment systems and card terminals work via WiFi without any issues. But in 2016, the reality was quite different. Bar operators didn't trust wireless connections for processing payments. A WiFi failure meant losing out on revenue. Nobody wanted to take that risk.
The card readers of that era were synchronized with a base station connected via an Ethernet cable. The server’s terminal connected to that base station via Bluetooth, and the base station required an Ethernet connection to communicate with the payment server. If the base station lost its connection, all Bluetooth terminals linked to it would stop working. A single loose cable could leave an entire bar unable to process payments.
At the same time, the first cashless wristband top-up totems were appearing. The cashless payment model was starting to make its way into large festivals. These totems needed a stable network to process top-ups against the central server. They were a new element that added more wired connection points to an already enormous deployment.
The result was a colossal cable installation. Every counter, every totem, every point of sale was connected by Ethernet. We're talking about hundreds of wired connections spread throughout the venue. Literally thousands of meters of network cable. Laid across the venue floor, through temporary structures, along detachable bars, and in tents that changed location each year.
The backbone connections between zones were laid using fiber optics to ensure sufficient bandwidth. It was a massive undertaking that began days before the festival and didn't wrap up until just a few hours before the gates opened.
The technological moment: everything was changing
To understand the magnitude of what was being put together at Mad Cool, you have to place yourself in the exact moment. Between 2016 and 2018, the events sector was undergoing a period of technological transition. Many things that are taken for granted today were then just emerging or didn't even exist.
Mobile networks would easily become overloaded at large-scale events. Packing 80,000 people into a venue would cause the operators’ cell towers to crash. The first trucks equipped with mobile repeaters began to be deployed at major festivals to boost cellular coverage. But their capacity was limited and their cost was high. Relying on the mobile network for critical services such as payment processing or accreditation was not an option.
In the world of cabling, fiber optics had already become the standard for network backbones. Without it, the distances within a facility like Valdebebas would have been impossible to cover with copper. We were working with new protocols that allowed for better traffic management in high-density environments. 10 Gbps links already existed as a technology, but their cost made them unaffordable for most temporary deployments. We worked with what we had, optimizing every available megabit.
The 2.4 GHz Era and the Shift to 5 GHz
Back then, Wi-Fi operated primarily on the 2.4 GHz band. Almost all devices—cell phones, laptops, mobile payment terminals, and point-of-sale terminals—used that frequency. The problem is that the 2.4 GHz band offers only three non-overlapping channels. Three. For a venue with a hundred access points and tens of thousands of devices, that’s a massive bottleneck.
The 5 GHz band existed, but adoption was just getting started. Many client devices did not yet support it. As for point-of-sale systems and payment terminals, almost none did. This meant that most of the infrastructure had to remain on the 2.4 GHz band, accepting its limitations and fighting for every available channel.
The gradual switch to the 5 GHz band was a huge relief. More channels, less interference, and greater capacity per access point. But during those early editions of Mad Cool, the reality was that we had to deal with a congested band and pull off some RF planning miracles to make everything work.
Radio Links: The First 60 GHz Equipment
Another emerging technology was high-capacity point-to-point radio links. Connecting two areas of a temporary venue via cable wasn’t always possible. Sometimes there was a road in the way, a structure blocking the path, or a distance that made laying copper or fiber-optic cable impractical.
Radio links solved that problem by sending data through the air between two aligned antennas. The first 60 GHz equipment was starting to come to market. They offered bandwidths of several gigabits per second, enough to replace a fiber backbone over short distances. But they were new products, expensive, and with little history in real production environments.
Working with these technologies in the early stages required technical expertise that went beyond simply reading the spec sheet. You had to know what the manufacturer promised, what it actually delivered in the field, and what safety margin to build in to avoid any surprises on the day of the event. One thing was what the spec sheet said under ideal conditions. Another matter entirely was the actual performance in the face of interference, wind, humidity, and thousands of people moving around the venue.
That ability to evaluate emerging technology and decide when to adopt it and when not to is something that can only be developed through real-world testing. Mad Cool was one of those environments where technologies that are now standard were first put to the test under production conditions.
Every shot was sacred
At a festival where all bar revenue depends on the network, every wired connection is critical. If a cable fails at a bar that brings in thousands of euros per hour, the impact is immediate. That’s why every outlet was labeled, tested, and mapped to a specific switch port.
Whenever an issue arose—and in a temporary venue with thousands of people stepping on cables, issues were bound to arise—the technical team could pinpoint the problem in seconds. We knew exactly which cable, which switch, and which port was affected. That meticulous documentation was one of the first lessons we learned, and we continue to apply it today in every deployment.
100 to 120 Wi-Fi access points: coverage in every corner
In addition to extensive cabling for payment processing, the festival needed WiFi coverage throughout the venue. Accredited press were sending reports in real time. Artists and technical crews needed network access backstage. Brand activations required internet for their interactive installations. Sponsor booths requested dedicated connections.
To cover all of that, we deployed between 100 and 120 access points for each edition. These were distributed across stages, press areas, backstage, dining areas, VIP spaces, and the exhibition zone. Each AP was positioned according to a prior coverage study, with its assigned channel and adjusted power to avoid interference with neighboring APs.
But a festival isn't an office building. The layout changed from one year to the next. The stages moved. The bars were relocated. Tents popped up in new spots. That meant we had to redesign the Wi-Fi network from scratch every year. We couldn't just copy and paste anything from the previous year.
2018: The leap to Valdebebas and the 80,000 people
The third edition marked a turning point. The success of the first two editions made it necessary to find a larger venue. Mad Cool moved to Espacio Mad Cool, next to IFEMA in Valdebebas. The daily capacity jumped to 80,000 people. Seven stages: four outdoor and three under a tent. A venue spanning 185,000 square meters.
For enbex, this leap dramatically increased the scale of the deployment. We went from a familiar, relatively compact venue like the Caja Mágica to a massive space that had to be wired from scratch. The distances between areas doubled. The number of bars and payment terminals grew in proportion to the venue’s capacity. And requests for connectivity at booths and brand activations skyrocketed.
Every sponsor wanted internet access for their activation. Every brand in the exhibition area requested its own dedicated connection. The food courts, now much larger, needed more network access points than ever before. It was like setting up a temporary city with its own telecommunications infrastructure in a matter of days.
Marathon assemblies
The network installation at Valdebebas was the longest and most demanding of the three years. Additional kilometers of cable. Longer runs of fiber optic cable to cover the distances within the new venue. Additional distribution switches deployed at intermediate points. And all of this while working to an installation schedule that had to compete with those for the stages, lighting, sound, and catering.
Coordinating cable runs with the rest of the setup crew is an art in itself. You can’t run cables where a truss is going to be installed the next day. Nor can you wire a stage area if the structure isn’t finished. The network team has to adapt to the overall setup schedule, take advantage of time slots, and sometimes work in the early morning to make progress without getting in the way.
Those were long days. Very long days. But those days forged a seasoned team that today builds complex infrastructure with a level of efficiency that can only be achieved by going through experiences like those.
The Nightmare of the Card Readers (and How It Was Solved)
If there's one thing that marked those early years, it was the card readers. The base-Bluetooth system we described earlier generated a fragile chain of dependencies. The waiter's terminal depended on Bluetooth. Bluetooth depended on the base. The base depended on the Ethernet cable. The cable depended on the switch. And the switch depended on the fiber backbone.
Any link that failed left an entire bar unpaid. At a festival with dozens of points of sale operating simultaneously, diagnosing whether the failure was in the Bluetooth, the base, the cable, the switch, or the trunk line was an exercise that had to be done in minutes, not hours.
To that, we had to add the wristband top-up totems, which shared the same network and added extra traffic. A totem processing top-ups generates data bursts against the server that compete with the payment terminals for the segment's bandwidth. Without proper segmentation, one could affect the other.
We learned to treat the billing network as a mission-critical system. Its own segment, isolated from the rest of the traffic. Absolute priority on the switches. Redundancy in the links within the bus zones. And above all, a rapid diagnostic protocol that worked its way link by link until it found the point of failure.
Those lessons still hold true today. Terminal technology has changed, but the philosophy hasn't: the payment network cannot go down. Ever.
Behind the scenes: where the internet is also essential
There’s one part of the festival that the audience doesn’t see but that needs internet access just as much—if not more—than the rest: backstage. Artists, managers, promoters, sound and lighting crews, and festival production staff. They all need internet access.
Setting up WiFi in a festival backstage has its own specificities. Dressing rooms are temporary structures that are assembled and disassembled. Artists' technical riders sometimes include specific connectivity requirements. The festival production manages timing, incidents, and internal communications through the network.
At Mad Cool, we provided dedicated WiFi networks in the backstage areas, isolated from public traffic and with the necessary bandwidth for production teams to work without relying on mobile coverage. In a venue with 80,000 people saturating operator antennas, 4G coverage was practically unusable. enbex's WiFi network was the only reliable option.
What We Learned: Three Years That Changed Everything
Mad Cool was one of those projects that leave a mark. Three editions compressed a lot of learning in a short time. Each edition brought new challenges, and each challenge left a lesson that is still relevant.
We learned that the collection network comes before everything else. That a festival grows faster than any forecast and you have to design with a margin. That cabling in temporary venues demands logistics as meticulous as that of the stages. That documenting each outlet and each switch port saves hours of diagnosis when a problem arises at three in the morning.
We also learned to work under pressure unlike anything else. When there are six hours left until the doors open and 200 meters of cable haven't been laid, it's not worth looking for blame. It's worth laying cable. That mentality of solving first and analyzing later has been part of enbex's DNA ever since.
Today, Enbex executes dozens of projects every year. International congresses. Sporting competitions. Football matches. Music festivals. Product presentations. Private corporate events. Television broadcasts. Each with its own demands and complexity. Mad Cool was one of the first large projects. The kind that force you to grow quickly, to solve problems without excuses, and to never forget what works under pressure.
Deployment Specifications
Event: Mad Cool Festival — 2016, 2017, and 2018 Editions.
Seats Magic Box (2016-2017) and Mad Cool Space in Valdebebas (2018).
Assistance From 100,000 people in 2016 to over 240,000 in the 2018 edition.
WiFi Access Points: Between 100 and 120 APs per edition, with RF design specific to each venue configuration.
Wiring Thousands of meters of Ethernet and fiber optic cable. Hundreds of dedicated wired connections for bars, checkout counters, payment terminals, stands, and brand activations.
Services Network for payment processing and card terminals, WiFi for the press, artist backstage areas, festival production, sponsor activations, VIP areas, and food service.
Legacy One of enbex's first major projects at music festivals. The operational experience gained here adds to the knowledge that is now applied at conferences, festivals, and large events.
Do you need a team with real experience in major events? Contact enbex. We've spent years building what others don't dare to build.