The first thing to note is that providing Wi-Fi on trains is relatively straightforward. It’s providing internet connectivity to the trains Wi-Fi system that is tricky. This is similar to having a great mesh Wi-Fi system in a building, but with a poor broadband internet connection. No matter how good the Wi-Fi is, without a reliable, good-bandwidth broadband connection to the building the end service to the device and the customer experience will be poor. It is the same with a train.
With widescale societal use of internet connectivity, both for leisure and business purposes, there is an expectation by many that a connection to the internet will always be available on a train. It is said by some studies that, on average, people spend more than 25% of their waking day online and for nearly two thirds of people not having reliable internet access is the cause of significant stress when they are out and about. Workers are increasingly flexible with remote-working and they need to be able to use trains as a place of work when travelling.
However, trains are fast-moving, often densely populated metal boxes which shield radio signals. Connectivity ‘on the go’ needs seamless handover between Mobile Network Operators (MNO) base stations and Wi-Fi access points within the train itself. Good network capacity planning is also needed to handle the load efficiently and provide satisfactory service to all passengers.
It is possible to obtain internet connectivity direct to devices, such as smartphones on trains, without Wi-Fi. However, by virtue of their construction, train vehicles create attenuation which degrades the usable signal into the train vehicles. This can typically be between -5 to -35dB, with a loss of 3dB resulting in halving the available power. The rail network in Great Britain extends for some 15,750km, of which 6,300km is in cuttings of various depths, and this creates further difficulties in providing continuous coverage to and from MNO base stations. Another problem is that such is the popularity of Wi-Fi that nowadays many devices, such as laptops and tablets, are only provided with Wi-Fi and do not have an MNO connection. This means a reliable good quality Wi-Fi service has become an expectation of rail travel.
The most common method of providing a train internet connection to the Wi-Fi system is by using an external mounted wideband antenna connected to a communications device known by some providers as a Mobile Communications Gateway (MCG). The MCG, or a number of MCGs, provide ‘a cloud’ of connectivity to the train via several MNO services (and, where available, external Wi-Fi connections at stations) aggregated together.
The internet connection is provided throughout the train via a number of internal vehicle Wi-Fi access points, typically using the train’s Ethernet network with appropriate security and firewall protection. Robust inter-vehicle connections are used to connect the access points, or point-to-point Wi-Fi may also be used to connect access points. These use low power and directional antennas to minimise the risk of bleed through to adjacent trains. Security is also very important, which requires encryption and authentication to protect passengers’ sensitive information. The security threat is always changing, and the defences must be continually upgraded.
Over the years, providing internet connectivity and Wi-Fi on trains has become ‘a victim of its own success’, with the use of devices on trains increasing dramatically and applications such as Netflix, YouTube, or any streaming service, needing access to extensive data bandwidth, and far more than the Wi-Fi systems on trains were typically designed for. Wi-Fi service on a modern busy train using aggregated MNO links can be likened to a fast-moving street with several people in each house ‘gobbling’ data and with only one poor broadband connection for the entire street!
Another problem is that the MCG, Wi-Fi Access points, and train Ethernet networks quickly become obsolete and need upgrading or replacing every few years – far more frequently than the typical mid-life upgrade refurbishment timeframe of a train. The MNO links will also need paying for, but the train customers expectation is that the train Wi-Fi service will be free, just like it is in most public areas outside of rail. All this means that the on-train Wi-Fi service available on some trains has become embarrassingly limited, resulting in poor passenger satisfaction scores.
Blu Wireless
The 44-mile South Western Railway scheme deployed by First Group PLC (owners of the SWR franchise) uses dedicated small mmWave wireless access points every few kilometres, developed by Blu Wireless Technology Ltd based in Bristol. The LightningBlu, Blu Wireless solution provides symmetrical Gigabit data throughput and low latency connectivity between trackside and train, using the 57GHz to 71GHz unlicensed frequency band. This is a huge improvement over the solutions based on aggregating MNO services deployed on most trains to provide on train Wi-Fi.
A number of initiatives have been developed to aid installation and reduce costs. For example, the Stanchion Mounted Pole (SMP) is a lightweight, non-conductive plastic pole attached to an electrification stanchion. This removed more than half of the survey requirements and made installation far easier and quicker. Unfortunately, the GHz frequencies need frequent (every few km) fibre cable break out points and power supplies, which are difficult and expensive to provide. It is also possible to use point-to-point radio links to serve the access points instead of fibre, but again a local power supply will be required, although this situation may improve with the development of localised green energy sources, such as solar.
All is not lost though, as Blu Wireless’ gigabit wireless solution has recently been boosted by a deal with Westermo which is a manufacturer of data communications solutions for mission-critical systems in demanding environments, such as rail transport, utilities, mining, and petrochemical industries. They have acquired a stake in Blu Wireless, a seat on the Blu Wireless board, and a strategic partnership agreement to use the mmWave wireless technology in the rail market. Westermo already provides many data network products and solutions on trains and has extensive international experience. They are very well placed to further commercialise the mmWave technology in the rail sector along with the development of future products.
Deploying fibre cable trackside may not be easy, especially with the difficulty of working trackside safely, but the availability of high-fibre-count ribbon fibre cable helps, and it should be possible for the rail industry to work more efficiently and, for example, run fibre cable for trackside Wi-Fi points when resignalling work takes place.
Modern signalling systems also tend to use a more distributed trackside architecture approach which also needs power supplies. The GSM-R operational train radio masts (although provided for operational communications, not public use) are also located every few kilometres and with power. So, with better planning and collaborative working the industry could reduce costs and provide better train Wi-Fi.
Satellite connection
Internet connectivity via satellite connection is now commonly available for fixed use and on passenger aircraft, which raises the question of whether this could be used for trains? The answer is yes it can. Twenty years ago, a project called ‘Broadband to Trains’, partly funded by the European Space Agency (ESA), demonstrated the use of satellite communications to deliver broadband internet access to a train’s onboard system. Since then, Low Earth Orbit (LEO) satellites systems have been introduced with reduced latency and lower cost.
LEO satellites orbit the Earth, typically at a height of 180 to 2,000km (111 to 1,242 miles). Just over 100 miles may not be low, but it is significantly lower than the traditional geostationary orbit (GEO), satellites which are over 37,000km (23,000 miles) from Earth. LEO satellite networks are becoming popular because of their reduced latency and the lower levels of rocket power (and therefore cost) needed for launching.
GEO satellites can cover huge areas with a single satellite due to their height, but LEO satellites have to be deployed in ‘constellations’ that work together to provide coverage for larger areas. LEO satellites travel around the Earth typically every 90 minutes so they can’t keep ‘hovering’ above one specific area like a GEO satellite. LEO satellites are fast moving and can move in and out of range of receivers in just a few minutes. This means that the satellite dishes and receiving devices are more complicated, having to track the movement of the satellites, and constantly switch from satellite to satellite depending on which is closer. By their nature, passenger aircraft are closer than trains to LEO satellites, they don’t run in cutting or tunnels, and their receiving dishes are more stable. However, a lot of work has been done in this area and LEO satellite train internet systems are now being developed by several bodies, including European Union’s rail system authority (ERA), Europe’s Rail Joint Undertaking (EU-Rail), and the European Union Agency for the space programme (EUSPA).
In 2023, global satellite operator OneWeb undertook trials in the UK to use its LEO network to serve railways, with the aim of “providing resilient broadband for both operations and enhanced passenger experiences.” Called Project Sodor, in 2023 OneWeb tested a user terminal installed on a rail car on the North Yorkshire Moors Railway. More currently, The Clarus Networks Group is developing and trialling an efficient rail approved vehicle satellite ‘dish’ it refers to as a “tile”. Clarus is an agent for Starlink, the world’s first and largest satellite constellation with thousands of LEO satellites already in place.
Trains run in many deep cuttings and tunnels, along with travelling in many built up cities. Therefore, LEO satellite train connection systems may need supplementing with fixed fibre connected base stations.
Using LEO satellite connectivity for operational purposes may alarm some and may be considered to be a step too far, but it is already being suggested as a possible bearer network for the Future Railway Mobile Communication System (FRMCS). Certainly, high bandwidth lineside Wi-Fi connectivity would help immensely with non-safety operational railway applications.
Business case
Wi-Fi on trains will still need funding, but the industry and UK Government needs to look at on-train Wi-Fi as a service to improve rail use and not as a standalone business. Wi-Fi on the railways will help to increase productivity in the economy. Commuters can work on the go and leisure travellers can connect with friends, research their destination, and check live journey information. Since the pandemic emergency lockdowns, the level of train use is recovering, with the exception of first class. However, good quality Wi-Fi is essential for making the most of a business trip and working on the move.
Last year, the Department for Transport said it was looking to remove free Wi-Fi services unless train operators could demonstrate a business case. This was, however, based on a survey where passengers were asked what their priorities were with regards to safe stations, trains being on time, and clean toilets – hardly robust proof that Wi-Fi service is not seen as a requirement by passengers and is no longer justifiable. Good reliable connectivity is also of great benefit to onboard train systems such as CCTV, passenger information, and Train Control & Management System (TCMS) reporting.
Other countries are committed to providing on train Wi-Fi. For example, in Germany the government, Deutsche Bahn, Ericsson, Vantage, and O2 Telefónica are looking to bring better connectivity to railways, and the Gigabit Innovation Track (GINT) project is looking at the technical and financial options. In the US, Caltrain is rolling out the Blu Wireless mmWave system along the San Francisco to San Jose rail corridor with Alstom Nomad the prime contractor.
The new UK government, while supportive of rail, is going to have some very tough decisions to make, but let’s hope that Wi-Fi on trains is seen as an important service to grow rail travel and the economy, rather than a simple business case in its own right. A good internet connection and a reliable, affordable train service do not have to be viewed as separate issues. Consumers value reliable, uninterrupted internet access, and meeting the technological challenges will open new opportunities for rail use consumers.
The technological challenges of providing Wi-Fi on trains can be overcome, but it needs scalable infrastructure designed for trains, possibly deploying a combination of wired and wireless connectivity, using technology such as mmWave wireless with fibre-connected access points, wireless back haul, and satellite connections. The typical train onboard architecture is also in need of re-evaluation to fully meet future requirements, as these have not really evolved since the early 2000s.
The future of train Wi-Fi needs the development of cooperative solutions, affordable investment, and a robust industry strategy. Not the abandonment of in-train internet connectivity.
Lead image photo credit: ISTOCKPHOTO.COM/LAREMENKO
