When Syllas Rangel C. Magalhaes talks about mobile networks, you do not get buzzwords or tech jargon. You get someone who is genuinely curious about how things work. And more importantly, how they could work better.
“I have always found it fascinating,” he says. “I can send a message from my phone without any wires. But how does that actually happen?” That simple question led him from studying engineering in Brazil to researching next-generation communication systems at the University of Twente. Now, he’s asking an even bigger question: what if our networks could be smarter, faster, and use way less energy?
Why one signal is not always better than two
Syllas’s research is about getting mobile systems to cooperate on every level. Not just users sharing a Wi-Fi signal, but base stations sharing the load, antennas teaming up to send data more efficiently, and even mobile operators working together to reduce energy use across their entire networks.
One area he is researching is called joint transmission. Instead of your phone talking to a single base station, it could connect to multiple stations at once. In theory, that means a stronger signal and better reliability. But for Syllas, the big question is: does it actually save energy?
“In some situations, yes,” he says. “If you split the transmission between two points and do it right, you can deliver more data without using more power. But in other situations, it does not help, or even makes things worse.” That’s the nuance he brings to the field. While some studies paint joint transmission as a silver bullet, Syllas looks at the whole picture: processing power, fixed energy costs, and the complexity of real-world networks. “We have shown that it depends. And understanding that difference is important if we want sustainable networks.”
Goodbye to signal dead zones?
Where it really gets interesting is a concept called ‘cell-free massive MIMO’. The idea sounds simple: instead of relying on big towers in fixed locations, scatter lots of smaller antennas throughout the city. For example, on rooftops, streetlights, and lampposts. Wherever people are, the antennas are too.
“Right now, networks are built around the infrastructure. But with cell-free, it is the other way around. The user is at the centre,” Syllas explains. “The network adapts to your location and chooses the antennas that are closest to you.” And that closeness matters. The shorter the distance, the less power your phone needs to connect. Multiply that across millions of devices, and the energy savings start to add up.
In simulations using actual Dutch city data, Syllas tested what would happen if every lamppost became a network access point. The results? If planned correctly, it could lead to big efficiency gains, especially in dense urban areas. But again, it is all in the details: how many antennas, where to place them, and when they should be active.
Is 6G already on the way?
While most of us are just getting used to 5G, Syllas is already thinking about what comes next. His research (in the scope of the 6G FNS project) feeds directly into the development of 6G: networks that will need to be not only faster and more responsive but far more sustainable.
“That is the exciting part,” he says. “We are not just building for speed anymore. We are building for energy efficiency, for climate impact, for the long term.” One part of that shift means thinking beyond mobile phones. Syllas recently started a postdoc (in the scope of the MISD project) exploring how data centres (the backbone of the internet) can also be made more efficient. “We are asking questions like: where should we process data? Can we move it around to use greener energy sources?” It is the same mindset, just applied to a different part of the puzzle.
Always wondering what is behind the screen
What makes Syllas’s work stand out is how personal it is. You get the sense he is not doing this just to publish papers. He really wants to understand the systems we all take for granted. “There is this whole world behind your smartphone,” he says. “Most people never think about it. But if we can make that world more efficient, more intelligent, that affects everyone.”
And that is the goal. Not to redesign the internet overnight, but to ask better questions, challenge assumptions, and slowly build networks that are smarter, greener, and better aligned with the way we actually live.
