Britain needs a rail connectivity strategy built for the next 30 years

Britain has an opportunity to make a decisive improvement to rail connectivity. It also risks letting a proposed solution create a glass ceiling for a much longer-term decision.

Last week, the BBC reported that Transport Secretary Heidi Alexander is expected to announce plans this summer to upgrade onboard Wi-Fi across more than 1,400 trains using low-Earth-orbit (LEO) satellite connectivity, aiming to increase availability from around 50–60 per cent of journeys to more than 90 per cent. That ambition is right, as passengers have tolerated poor connectivity for too long, and satellite services can extend coverage quickly, particularly on rural routes and locations where trackside deployment is harder to deliver.

However, satellite alone cannot future-proof the railway. It improves coverage and plays a genuine role within a hybrid architecture. But shared bandwidth, line-of-sight obstruction in tunnels and throughput constraints mean it cannot provide the sustained, scalable capacity that the busiest routes will require as passenger and operational demands grow. The industry needs to be crystal clear about that distinction as it plans its next infrastructure cycle.

UK rail is making decisions that will shape its digital capacity for decades. Connectivity infrastructure that performs adequately today may become a constraint well before it is replaced. Real-time CCTV, predictive maintenance, digital twins and AI-enabled applications will all increase the volume of data trains need to move reliably – and passenger devices will certainly demand more too. The connectivity specification written for today’s railway will not be adequate for the railway of 2035. Planning for that trajectory now is the task facing Great British Railways (GBR) as it builds a long-term infrastructure strategy.

South Western Railway (SWR) has already demonstrated what the right architecture looks like. Its network combines mobile connectivity, LEO and Blu Wireless’ dedicated trackside mmWave infrastructure. On the 70-kilometre section served by mmWave – one of the busiest parts of the route – trains receive a dedicated, high-capacity connection that is independent of the variable performance of the surrounding cellular network. This backbone gives train fleets the backhaul capacity their existing systems need to perform.

Passengers are already benefitting from that capacity. South Western Railway has told us that passengers travelling through the mmWave-enabled section make a combined 289 hours of Microsoft Teams calls and stream 256 hours of YouTube content each day. Commuters can treat their journey as working time, while leisure passengers can access the streaming services they use at home. For operators, that creates a strong customer proposition and a creates a more competitive railway.

The infrastructure behind those results has now received independent validation. An independent study commissioned by Ofcom measured mobile and onboard Wi-Fi performance across 50 journeys on 24 rail lines. Between Earlsfield and Basingstoke, where Blu Wireless’ trackside mmWave infrastructure is deployed, the study found that its Good Performance threshold was met 83.2 per cent of the time. Across the remainder of the journey, performance fell below 1 per cent. The study describes SWR routes as showing a fundamentally different Wi-Fi performance profile to other train operating companies – and attributes that directly to the dedicated bandwidth provided by trackside mmWave backhaul.

This is also a commercial argument. When the available mobile signal is weak or congested, the onboard system cannot allocate bandwidth it does not have. Blu Wireless addresses the underlying capacity constraint by providing a dedicated connection to the train fleet that operates in licence-exempt spectrum. That means the backbone can absorb increasing data volumes without the per-gigabyte cost escalation that makes cellular-dependent models harder to defend at scale. For operators, lenders and those responsible for long-term rail funding, an infrastructure-led model offers more predictable spend and lower financial exposure over time.

I want to acknowledge the teams who made this possible. Reaching live service and having that service independently validated has required years of engineering work, close collaboration with South Western Railway and the trust of partners across the rail ecosystem. The Ofcom-commissioned study is an important confirmation that the technology works in the real world, at scale, on one of Britain’s busiest commuter routes.

Two hundred years ago, Britain built infrastructure to move people and goods across the country. The railway now needs infrastructure capable of moving data at the same scale. That infrastructure is less visible than a viaduct, but operators will depend on it just as heavily as passenger and operational demand grows. The industry’s decision is how to build it well, leverage satellite where it adds genuine value, keep mobile networks as an integral part of the solution and deploy dedicated mmWave capacity on the sections where demand requires it. The evidence that this approach works is already on the track.