Internet of Things (IoT)
What is it
The Internet of Things (IoT) refers to the use of networked sensors, embedded devices and connected equipment that are able to collect, transmit and, in some cases, act on data with limited human intervention.
In rail infrastructure monitoring, this typically means instrumented assets on trains, track and lineside equipment that stream condition data into analytics platforms to support safer and more efficient operations (see AIVR).
IoT is closely linked to cloud computing, which provides scalable storage and processing for these data streams, and to edge computing, where processing is pushed closer to the asset to enable fast, local decisions (for example, on-board alarms or automatic protection functions).
Why it matters
In Rail infrastructure monitoring, IoT matters because it enables continuous, data-driven insight into the condition and operations of infrastructure and rolling stock, rather than relying solely on periodic, manual inspection.
This supports predictive maintenance, early-warning alerts for failures and better understanding of asset degradation over time, helping reduce delays, improve safety and lower whole-life cost.
At the system level, cloud platforms allow data from large fleets of geographically distributed assets and infrastructure to be aggregated for analysis, modelling, visualisation and reporting. While edge devices filter, compress and pre-analyse raw feeds so only the most relevant data is transmitted, controlling data volumes and improving response times.
Who uses it
IoT is used by a wide range of stakeholders across the rail ecosystem. Infrastructure managers deploy fixed and wireless sensors on track, structures, earthworks, power and signalling to monitor condition and environmental factors. Train operators, vehicle owners and maintainers use on-board monitoring for wheels, bearings, braking systems, doors, HVAC and energy usage, while control centres, timetable planners and even regulators consume the resulting information products for operational decision-making and performance management.
When: key dates
The underlying technologies – networked sensors, embedded systems and industrial telemetry – predate the term, but “Internet of Things” as a phrase has emerged over the last 20 years. During this period, improvements in network connectivity, lower cost sensor technologies and cloud computing have made large-scale data collection, storage and analytics flexible and economically viable, and so adoption accelerated across sectors including transport and rail.
Today, IoT is often discussed alongside concepts such as cyber-physical systems, the Fourth Industrial Revolution and smart cities, with rail positioned as a key domain for large-scale, safety-critical deployment.
How it works
In rail infrastructure monitoring, an IoT system typically compromises:
- On-board or trackside devices: sensor nodes measuring vibration, temperature, displacement, strain, position, current draw, video and more, often with integrated microcontrollers, local storage and power management.
- Edge processing: on-train gateways or lineside units that fuse multiple sensor feeds, run threshold checks or simple machine-learning models, and manage local buffering when connectivity drops.
- Communications: cellular (4G/5G), Wi-Fi, low power WAN (e.g. LoRaWAN, NB-IoT) or private radio backhaul to move data securely from field devices to back-office systems.
- Cloud platforms and applications: scalable ingestion, time-series databases, analytics and visualisation tools that turn raw telemetry into alerts, KPIs, digital twins and decision support for engineers and controllers.