In their bid for automation and greater efficiency, rail operators are always looking to implement more advanced technologies on their fleets.
But for smart trains to truly work, this requires industrial-strength connectivity, enabling reliable communications between the likes of sensors and other remote devices on the network.
Take, for instance, positive train control (PTC), the advanced safety system designed to automatically apply the brakes on a train to prevent accidents, such as collisions and derailments. In recent years, PTC has attracted increasing interest across the rail industry – particularly in the US – as it seeks to better monitor and control operations.
Comprising of numerous technologies, including global positioning system (GPS), onboard computers and digital communications, PTC systems are reliant on wireless networks to transmit information between all of these different components. In the US, such systems tend to use a licensed radio frequency band of around 200 megahertz (MHz).
“Secure and reliable connectivity is critical for providers when it comes to communication with sensors and other remote devices,” says Stewart Kantor, CEO and co-founder of Ondas Networks, a Silicon Valley-based wireless networking group.
“It’s a particular priority in the class I railroad market [railroads in the US are classified as either I, II and III according to size. Being the biggest bracket, I includes the likes of Amtrak and the Union Pacific Railroad]. They see it as a means of ironing out efficiencies and lowering costs.”
A gap in the market: Ondas’s networks and moving blocks
Although Ondas was founded in 2006, the group only started working with the rail industry in “mid-2018”, when it spotted a gap in the market to help operators better utilise existing spectrum to create higher-capacity networks, capable of supporting IoT operations. In addition to PTC, Ondas’s networks can be applied to line-condition monitoring, rail crossing and station automation.
Another area Ondas is particularly interested in is moving block, a radio-based signalling system whereby trains are controlled and kept a braking distance apart using blocks defined in real time by computers as safe zones around each train. As well as introducing greater safety on the tracks, the system is also recognised as a means of bolstering a line’s capacity.
“For obvious safety reasons, there has always been a need to create enough space between trains,” says Kantor. “But with additional sensor-type data along the tracks and along the train, today’s moving block technology actually allows the trains to be closer together but still at a safe distance. Basically, you are creating one long, just-in-time train on the track. The efficiencies go way up.”
Radio silence: how operators can do better with their licensed spectrum
One market trend Ondas has identified and is looking to exploit is that while rail operators in the US have their own licensed spectrum – from very high frequency (VHF) to ultra high frequency (UHF) – capable of establishing secure networks, modernisation still appears to be wanting.
“I’d say that one of the reasons that the industry has embraced our technologies is that we’re taking frequencies that have been allocated to them and are making them more efficient,” explains Kantor.
“Historically, rail providers have introduced single-purpose networks over time, but what our technology allows them to do is take these various frequency bands and use them more efficiently, with a higher capacity. This allows them to carry more data traffic.”
The pre-existing issue for rail providers in the US, says Kantor, is that the spectra they use are disparate and often based on legacy technology, which “breaks bands into small channels without getting a lot of efficiency”.
“The reason they are turning to technology like ours is that we allow them to use all these bands, from 160MHz to 900MHz, within a single radio architecture, allowing them to get more capacity. This also enables them to transition away from the voice-centric technology of the past to a more data-centric technology.”
The next frontier: challenges around 5G and a new global standard
According to Kantor, there has been a spike in demand for these bands – licensed out by the US Federal Communications Commissions, the agency in charge of regulating radio frequency use – as they are typically of a lower frequency and can transmit at a much longer range.
But what about the impact of 5G – the next frontier in wireless communications? While its rollout in the US has been fragmented, as it has been across much of the globe, how big a consideration is it for communications-focused rail providers? There are issues that still need to be ironed out, says Kantor.
“One of the problems with 5G, just as there was with upgrades to 4G and 3G, is that the coverage is much smaller,” he explains. “There are also different requirements to consider for rail, compared to consumer-grade networks.
“The move to 5G means more tower sites and higher infrastructure costs in order to create coverage. The big challenge is not necessarily capacity – it’s also about maintaining critical coverage.”
Crucially for Ondas’ customers from the rail industry, the group’s technology is compliant with IEEE 802.16s, the new global standard for private licensed wide area industrial networks introduced in 2018.
“The new standard is focused heavily on the critical aspects of rail, which includes rail-side monitoring, moving block and signalling,” says Kantor. “We are happy to be working with it.”