Use of broadband technology for mission-critical train radio communications

If you live in or around a big city like Sydney or Melbourne, you will have traveled by train at some point. Most people would understand the basics, such as the signal being green, the train arriving on the red signal for a short period of time until the first train has moved a safe distance away, allowing the signal to turn green again. There are signals located in each sector, where the trains pass and they are very reliable; if the signaling system fails then all the trains stop and you have a fault on the right hand side. When the signaling system no longer works correctly or if it has received conflicting data from the road circuits, all signals show a red signal and the driver must be authorized by the traffic controller to pass.

The conductor, after waiting a short period of time, contacts the signalman using a train radio for permission to run a red signal. The train radio is used for mission-critical communications, because passing a red signal can cause an accident, such as a train rear-ending another, or a head-on collision if you are on a siding entering a major track. .

The origins of modern train radio go back 40 years, to 1977, when a paper written by Clive Kessell on “The Development of Radio Communications between Signalman and Driver” was presented at a meeting of the Institute of Railway Signaling Engineers to promote interest in the development of radio. communication between the train and the signal box. Radio communications were the best way to stop a train or move one that had stopped; it is safer to keep the conductor on the train rather than walk the track looking for a signal pole phone to communicate with the signalman.

At this time a communication standard called UIC751-3 was developed which created a 4 channel UHF analog train radio network which was implemented around London’s Kings Cross and St Pancreas station; it was also deployed in parts of Europe, notably West Germany, where much of the early development occurred.

Metronet analog train radio was rolled out in Sydney in 1994 at the same time as a very similar radio system called “Cab Secure Radio” was rolled out in the UK and other parts of the world. In the early 2000s, a newer radio network based in Europe was developed on the popular GSM standard. By moving from an analog network to digital voice, voice quality was improved and the unwanted static for which analog communication was notorious was reduced. This Digital Train Radio System (DTRS) was commissioned in 2017 in Sydney to replace the analogue Metronet and improve rail communications.

However, the pace of change for mobile phone companies has been rapid, GSM (a second generation technology) on which DTRS is based is now almost obsolete; We’ve all come to love the benefits of advanced fourth-generation mobile phone technology. In the rail sector, there is considerable interest in what technology will be used to replace DTRS, how it will be developed, and when it will be implemented.

My research looks at these issues to identify how a fourth-generation modem broadband mobile technology can be developed to provide all the mission-critical communication needed to run trains along with the benefits that high-speed broadband data can provide such as CCTV in real time. The risk averse nature of railways views any change as an increase in risk, so they have become process change averse. However, by keeping the old technology, the risk increases because the security benefits associated with the new forms of communication are not obtained; there are also the technical challenges of keeping incompatible equipment running when replacement hardware components cannot be found.

Operating a modern railway like the one in Sydney, where there are a million passenger journeys a day, really requires a modern communication system so that safety is not compromised. The signaling system is reported to have a fault on the wrong side once every thousands of years, but they happen for reasons no one considered.

The train radio allows the driver and signalman to take corrective action immediately to prevent an accident from occurring; save many people from serious injury or death if you are in a train accident. Fourth-generation mobile communication is now a proven technology that can provide the mission-critical communication that allows GSM-R to retire sooner rather than later.