What The UK Rail Industry Needs to Know About New Availability of the 39Ghz Spectrum by Ofcom

Chris Spencer, CTO, GlobalReach Technology

The UK telecoms regulator Ofcom has signalled that it will make the 39GHz spectrum band available as a way to provide consistent “track-to-train connectivity.” This follows news across the globe of the opening up of new spectrum which will support new Wi-Fi services and better user experiences across the board.

This latest development sees Ofcom updated its advice to the government adding the new band as a possible option to support on-board, ultrafast broadband capable Wi-Fi access points or mobile (4G, 5G) small cells for commuters. We now wait for a formal confirmation.

This is welcome news and in line with a raft of other announcements from the industry, which support the goal of the Network Rail CEO, Andrew Haines, who on his appointment in 2018, pledged to improve “the services that the railways provide to customers and the wider economy.”

It’s an exciting development for those of us looking to improve the passenger experience through an uninterrupted connection between trains and stations – whatever the passenger route. 

For context, it’s worth noting that, despite growing passenger demand for high-quality Wi-Fi, the latest National Rail Passenger Survey (Spring 2020) found that 42% of passengers were dissatisfied with the availability of Wi-Fi, and there was just a three per cent increase in national availability between Spring and Autumn 2019.

A second 2019 report by umlaut for Transport Focus to understand and evaluate consumer experience and satisfaction of mobile connectivity when using Great Britain’s rail network found that Wi-Fi only carried 4.3% of on-board passenger traffic (although more data is consumed per user when Wi-Fi was used), and that around 85% of passengers could get some form of 4G coverage.

As we’ve previously said, there is no technical reason why a passenger moving from one train service to another cannot register once and be connected seamlessly throughout their rail journey. We believe that putting this connectivity in place will have a direct impact on passenger satisfaction ratings and loyalty.

In fact, GlobalReach is involved in many live examples of both ‘Wi-Fi only’ and hybrid cellular/Wi-Fi networks already delivering this constant connection to end users.

What’s Different About Rail?

While it’s taken the UK government a while to reach this position, it’s spent time considering each potential technology within the specifics of the bounds of somewhat tricky rail infrastructure.

As both passenger services and train operating systems need better connectivity, there is a need to get large volumes of data on and off the train in a reliable manner. In this use case satellite technology is unsuitable because of the environmental challenges of tunnels, deep cuttings, and tall artificial trackside banks being used to disperse the noise. 

Satellite backhaul requires true line of sight at all times (even newer low earth orbit satellite technology needs a good line of sight), so rail environments would rule this out as a viable option. 

Antennas on the top of trains also present issues to constant connectivity. Large bursts of electrical magnetic interference from overhead cables and multiple frequency jumps from base station to station are coupled with the issue of towers not always being in the best places.

A Solution for Uninterrupted Connectivity

A dedicated frequency that can be installed close to the ground, directed at the train, with optimal antenna alignment will allow for reliable connections to and from the trains. 

Tracks are well designed with cable ducts to carry fibre cables so it’s very easy for them to be installed. To combat the instability of locating antennas on the train roof, fixing them to small one metre poles aligned to the side of the train rather than the roof is a workable solution.

When spectrum is increased, these high frequencies will be able to carry a lot of bandwidth if the channel widths are quite large also. It should allow for a ubiquitous network.

Once trains have reliable high-speed backhaul, then the last mile (or feet) will be delivered via Wi-Fi technology or even small cells. We already know that Wi-Fi can provide all the services a typical commuter’s mobile device needs (including Wi-Fi calling).

Any Outstanding Questions?

Well, yes…. If and when this spectrum is confirmed, it will be interesting to see how it’s licensed and how it will be deployed.

A possible ecosystem could be that spectrum is deployed by the TOC, or by Network Rail or some other third party entirely that pays for the Ofcom license, and then each train that connects to it is charged a service fee. A telecom carrier could easily and quickly fulfil this role. 

As with all moving vehicles consuming fuel, it will also be interesting to know the weight of 12 small cells and the headend equipment needed to operate an onboard service (assuming 12 carriages on the long runs).  Alongside ease of deployment and technical viability, this will also help rail companies to consider the opex of fitting onboard 5G when Wi-Fi can deliver everything from passenger connectivity through to data offload for train operating systems to laptops, mobile phones and non-SIM devices today.

GlobalReach can help you to understand the implications for your on-board rail services. Get in touch now.