Why Wi-Fi on Europe’s trains isn’t working

BRUSSELS — It’s summer. You’ve hopped on a train to glide through Europe, laptop open, to-do list ready — but the onboard Wi-Fi has other plans. Emails don’t send, pages don’t load, and streaming? Forget it.

European rail companies often tout connectivity in trains as a perk, but for many passengers, it’s still an exercise in patience over productivity.

“The performance and quality of Wi-Fi onboard European trains is very poor,” Luke Kehoe, an industry analyst at connectivity intelligence firm Ookla, told POLITICO.

The high speed of a train makes it predictably difficult for Wi-Fi antennas in a carriage — or your smartphone — to keep a steady connection between changing mobile towers.

“If a train is going at 200km an hour, the device could be crossing a cell site every 45 or 60 seconds, which is a rapid turnover,” Kehoe said. “What that introduces is a technical challenge called the Doppler effect.”

That is when moving fast changes the signal’s frequency— like when a siren shifts pitch — and it can mess with the ability to hold onto a stable connection.

On French SNCF trains, travelers logging onto the Wi-Fi receive a pop-up warning: “Due to the lack of coverage and our speed, the quality of the Wi-Fi may differ from that in your home.” It also advises against watching online videos, which “contributes to limiting the bandwidth.”

‘Hello? You’re breaking up …’

But bad train Wi-Fi isn’t just about pace or tower count. Many cabins aren’t actually designed to let radio frequencies in. “A lot of trains would have historically used windows that have metalized or [low-emissivity] glass coatings that are inherently not conducive to signal propagation,” Kehoe said.

That setup would make the cabin similar to a sort of Faraday cage — an electromagnetic armor that blocks wireless signals, much like what causes your phone to drop calls in an elevator or keeps microwave radiation from escaping.

Last year, Belgian rail firm SNCB gave up on setting up Wi-Fi on its trains because of the “high implementation costs and coverage by telecom operators,” spokesperson Tom Guillaume said.

Instead, SNCB decided to pass the buck to telecom companies while it invested in “de-coating” glazing that is more conducive to mobile signals. “Telecom operators, therefore, need to improve signal quality and coverage in the vicinity of railway infrastructure,” Guillaume said.

The physics of radio frequencies are also well established: The band commonly earmarked for 5G in Europe isn’t great at cutting through trees and leaves, which often line train tracks. It makes it more challenging to reach cabins or phone users directly, in contrast with 4G, where the lower-band frequencies typically used can’t carry as much data, but travel further and handle obstacles better.

“We see in our data every summer a significant degradation in mobile network performance in areas of heavy foliage,” Kehoe added.

Add in the thousands of tunnels in the continent’s network, and it’s clear European trains have a tough job delivering solid Wi-Fi — though some countries manage to handle it better than others.

Switzerland leads the way by far, with onboard Wi-Fi speeds nearly 30 times faster than in Austria and the Netherlands. It was the only country in Ookla’s sample to break the 25 megabits per second median download speed mark — the minimum baseline for reliable internet use.

Trains are in for an upgrade

Some rail operators are now looking to the skies — literally — for better onboard internet, turning to satellite providers to help fill coverage gaps along train routes.

Czech Railways is experimenting with Elon Musk’s Starlink network, while France’s SNCF is reportedly eyeing both the U.S. constellation and its Franco-British rival, Eutelsat. SNCF didn’t respond to POLITICO’s request for comment.

While satellite connectivity works well for airlines — thanks to clear skies and proximity to orbit — it’s not a “bulletproof solution,” Kehoe said, but rather a supplement to the overall connectivity mix.

“So much of the focus is about getting the signal to the train, but they have forgotten about getting the signal around the train,” he said.

The Wi-Fi equipment and the standards behind it play a major role in how good the connection actually is.

Connections sampled by Ookla in Poland — which ranks near the bottom for performance — showed trains still running on Wi-Fi 4, a 2009 standard that offers far less bandwidth and much slower speeds than newer generations.

Whether rail operators upgrade routers or windows, “if there is no network coverage, there will be no mobile signal in the train, regardless of the technology used,” SNCB’s Guillaume said.

And if you’re thinking of just using your phone’s hotspot to get around a flaky Wi-Fi connection — think again. “If everyone is broadcasting their own Wi-Fi networks, there is a massive interference challenge here,” Kehoe warned.

Train internet still sucks — and getting a full steam ahead connection on Europe’s rails is set to remain hit and miss for a while.

Hanne Cokelaere contributed to this report.