It’s a pain for commuters: before a long-distance train journey, you want to put your laptop on the tray table in front of you and get some work done, but the on-board Wi-Fi connection is often spotty or barely functional.
Half of UK rail passengers surveyed by Transport Focus in July said they were dissatisfied with the reliability of their internet connection. Of all the aspects the rail watchdog surveyed passengers about, satisfaction with connectivity was the lowest, at 51%, 35 points lower than overall satisfaction with the rail service.
A 2019 study by the Department for Transport (DfT) found the problem is so severe that most passengers rely on their own (unreliable) mobile internet connections rather than train Wi-Fi: the DfT report found that only 4.3% of internet data traffic generated during train journeys used on-board Wi-Fi.
According to rail expert Christian Walmer’s conversations with industry insiders, passenger Wi-Fi usage on UK trains is around half the 50-60% rate seen in continental Europe.
One of the reasons why Wi-Fi on trains is unreliable is that it’s not true Wi-Fi. I He reports that it feels like it’s getting worse recently.
“We have a device on top of the train that contains about six SIM cards from each network operator,” Wolmer says. “It picks out the best signal and uses that to create Wi-Fi.” Each SIM card acts as a mobile-data router, collecting mobile Internet signals and redistributing them to users on the train below, just like a smartphone.
The problem is that 4G and 5G mobile internet connectivity is not widespread across the country, with only 69 percent of rural areas covered by all four major mobile networks.
Wi-Fi performance tends to be roughly the same between network operators, but routes closer to cell towers tend to offer more stable connections than rural routes further away from network coverage.
Even if a reliable signal could be collected from mobile data receivers mounted on top of trains, there’s another problem: Train operators have to pay mobile networks, so the amount of data available is often capped. “That’s why you can’t download a movie or have a long Zoom conversation because you don’t have enough data,” Walmer said.
What’s more, what little signal does reach the carriages runs into another problem highlighted in the Department for Transport study: if you were trying to design a system made specifically to limit the spread of Wi-Fi signals, you’d hardly be better off with it than the carriages of modern British trains.
Materials used in train cars, such as welded aluminum, form a so-called “Faraday cage” that blocks electromagnetic signals like Wi-Fi. Even the special glass used to insulate cars can weaken the strength of Wi-Fi signals. And because radio signals must pass through the human body to reach your device, a crowded train can also weaken signal strength and slow down your speeds.
An added problem occurs when the tiny bit of bandwidth that cellphone antennas can pull on the train exceeds data caps and is weakened by train carriage designs that make signal transmission particularly poor: What little Wi-Fi signal remains must be shared by everyone on the train. “When you have 20 people checking email at the same time, you hit a limit,” Walmer says, with a touch of hyperbole.
“Train Wi-Fi is a sweet match for connectivity providers and train operators,” said Paul Carter, CEO of wireless network benchmarking company GWS. “Trains are metal boxes that move fast and are often densely packed with passengers.”
And many passengers may find the situation worsening as in-flight Wi-Fi relies on increasingly unreliable mobile internet signals and has a host of issues: Past passenger surveys by Transport Focus showed that satisfaction with Wi-Fi connections was nearly 10 percentage points higher a year ago than it is now.
While the technology is in need of an update, it faces more fundamental infrastructure problems such as punctuality and train performance – in fact, the government told train operators in May last year to stop offering Wi-Fi services if they could spare the money to improve other areas.
But change could be coming soon: the new Labour government, coupled with plans to revitalise British Rail, the state-owned company that oversees all rail transport that has not yet been devolved, has a chance to change on-train Wi-Fi’s bad reputation.
“Deploying fast, reliable train Wi-Fi is not impossible,” Carter said. “The often underestimated part of this is making sure the entire network infrastructure is in good condition. This involves deploying a combination of wired and wireless connectivity solutions and leveraging technologies such as 5G, wayside small cells and even satellite connectivity to enhance the network’s range and capacity.”
But doing so will require momentum and a change of attitude. “Wi-Fi on trains should be like toilets,” says Walmer. “It’s unthinkable to run a train long distance without toilets. The same goes for Wi-Fi – it should be a basic amenity.”
Rail experts believe this will have another benefit: “It will bring people back to the railroads.”
