Using the FRNT ring protocol, failsafe backbone routers create fault-tolerant Ethernet networks

Although the rail industry presents challenging environments and

Reliable data

connection supports railway digitisation


he UK rail network is becoming increasingly busy and, consequently, demands on the intelligence of data networks are increasing.

Real-time data providing information on a train’s position, speed and direction is critical to maintain effective and secure traffic flow. In addition to this, there is a need for reliable and secure data networks on board trains to support applications and systems that enhance passenger journey experience and safety. Over the last few years the use of IP technology has become the standard for creating the data communication backbone used by train control management systems, passenger information systems, CCTV and infotainment systems. Robust Ethernet switches featuring a range of IP networking protocols are being used to build and manage these networks, which have become critical to the operation of the train. As more and more different types of equipment and systems are connected to these networks, the need for more ports and capacity is created. More equipment also means that more cables need to be installed both for power and data. Power over Ethernet (PoE) technology is the ideal solution to this issue, where end devices can be powered through the network cable, resulting in significant cost and space savings. Managed Ethernet switches, optimised for the needs of railway rolling stock applications, are available with PoE ports, offering effective powering of end devices such as cameras. In some train applications it is not possible to use network cables –

for example, to get information off a moving train to the ground, connecting carriages where a specialised train coupler is not available for network cables, or providing internet access for personnel and passengers. For these applications, robust wireless local area network (WLAN) devices are now available to ensure reliable, continuous, high-speed data communications, supporting applications such as monitoring train speeds and track conditions, and providing onboard video surveillance and passenger hotspots. Supporting communications from train to ground, the latest WLAN

devices offer high-output power for a stable connection. To achieve seamless communication as a train moves along the track, devices provide fast handover support, enabling switching from one trackside access point to the next. Inter-Consist Link (ICL) mode meets the challenge of providing stable and secure communication between consists, without incurring the cost of installing communication cabling over the couplers. Westermo’s RT-310 WLAN device is ideal for providing internet access to passengers, offering high-input sensitivity that enables a good connection even to weak signals, while fast connection support prevents passengers from enduring a long wait for connectivity to be established.

DEAL WITH A DYNAMICALLY CHANGING TOPOLOGY Several factors set train networks apart from traditional data


applications for data communications, networking technologies designed

specifically for onboard and trackside installations are providing the

reliability and resiliency required. Alan Bollard, managing director, Westermo UK, comments

networks. For instance, train networks must deal with a dynamically changing topology, as rail cars are connected/disconnected to the train. Train inauguration is a process where the data network can automatically reconfigure as carriages are joined or rearranged. The TTDP (Train Topology Discovery Protocol) used by the Westermo RedFox Rail backbone router allows this reconfiguration, which means staff operating the train do not need data network training. Train networks must also ensure high uptime by coping with potential failure scenarios. Using the FRNT ring protocol, failsafe backbone routers create fault-tolerant Ethernet networks, and dual bypass relay routers ensure that aggregated links between carriages are maintained, even if one carriage has a power failure. Network security is another crucial aspect, as cyberattacks and threats

intensify. A crucial part of meeting this challenge is ensuring that available device security features are correctly implemented. Westermo developed the WeConfig network configuration tool to simplify configuration of large and complex networks and it also makes it easy to achieve good protection against cyberattacks. WeConfig not only simplifies configuration, but it can also perform a security analysis and suggest changes that enable fast and efficient application of a system-wide security configuration.

A CHALLENGING ENVIRONMENT Onboard and trackside rail applications present very challenging applications for data networking technology. Products must be designed to withstand harsh environments and demands including constant vibration, extreme temperatures and humidity. Devices should be approved to the EN 50121-4 standard for trackside applications and, although devices are usually installed within cabinets for trackside applications, they should have the ability to prevent internal condensation and operate in temperatures of -40˚C to +70˚C. Devices must also be designed to provide a high-level of isolation

between all interfaces to protect against overvoltage and flashover. These features ensure device reliability and extend the mean time between failures. For onboard applications, one of the biggest challenges is available space. Devices with a compact design and the smallest possible footprint enable installation into the very tight confines of train carriages.



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