Train-to-ground links on a moving railway
Rail — high-speed, metro, urban, and conventional — watches the train, runs fault diagnosis, serves passengers, and manages maintenance through onboard terminals, trackside equipment, and a PIS. Trains move fast and spend long stretches in tunnels, so the module has to reject interference, hand over without a gap, and stay reliable. SimtoLink modules for this work are 4G / 5G / NB-IoT / LTE Cat.1, industrial-grade, with UART, SPI, and I2C. The company supports 500+ enterprise customers and has connected more than 10 million rail devices.
Where a rail module actually sits
Onboard PIS and CCTV, trackside monitoring, passenger services, and emergency links all depend on a cellular module. These are the jobs a rail project usually starts with, and the radio that tends to fit.
Onboard PIS and CCTV
A PIS and onboard CCTV send passenger information and video back over 4G or 5G as train-to-ground traffic. That supports passenger information, operations monitoring, and the safety level a railway expects.
Trackside monitoring and asset health
Track condition, turnouts, and the overhead contact line report through the module, for asset-health management and fault warnings that protect train running.
Passenger information and carriage WiFi
Platform displays and carriage WiFi go online through the module, for passenger information, advertising, and a better ride.
Maintenance vehicles and track works
Maintenance vehicles and track-works equipment carry a terminal that reports location and status, so maintenance dispatch and the work itself can be scheduled.
Emergency links and tunnel coverage
Tunnels and remote sections need a cellular module for emergency communication, including tunnel coverage, incident response, and evacuation.
Fault diagnosis and predictive maintenance
Onboard fault-diagnosis data goes up through the module for predictive maintenance, fault-code analysis, and maintenance decisions, which cuts unplanned stops.
What a moving train asks of the radio
- Several operators, and a handover with no gap: A train crosses regions. Several operators and bands are what hold seamless handover at speed and through tunnel coverage.
- Reliability at a rail safety grade: The module needs an industrial design, interference rejection, and stable running 7×24.
- Temperature and vibration: −40°C to 85°C, and resistance to vibration, for onboard and outdoor trackside sites.
- Bandwidth and delay: PIS and CCTV backhaul need a wide pipe. Some jobs also need low delay so monitoring stays live.
- Interfaces the train already uses: Onboard hosts and sensors, over TCP/UDP and MQTT, into the OCC and the maintenance platform.
Which radio fits onboard and trackside
A camera on the train and a sensor by the track do not ask for the same bandwidth, delay, or uptime. Onboard versus trackside, the bandwidth, and handover across operators should decide the module. The rows below are the usual pairing on a railway.
| Job | Radio | What matters |
|---|---|---|
| Onboard PIS/CCTV | 4G 5G | High bandwidth, video backhaul, train-to-ground, passenger information |
| Trackside monitoring | NB-IoT LTE Cat.1 | Infrequent reports, asset health, fault warnings, low power |
| Carriage WiFi / passenger services | 4G 5G | High bandwidth, many users, the ride itself |
| Maintenance vehicles / emergency | 4G | Several operators, tunnel coverage, running across regions, reliability |
How SimtoLink fits a rail program
For rail, the modules are industrial designs that hold temperature and vibration, with technical support 7×24. 4G/5G is the recommendation for onboard PIS, CCTV, and carriage WiFi, where the pipe has to be wide. NB-IoT or LTE Cat.1 fits infrequent reports from the trackside. Alongside the radio: one supplier for the module and the support around it, an SDK and API a vehicle team can bring up quickly, work with mainstream chip vendors, and a named account manager for the whole job.
Rail hardware is taken from the first requirements and the radio choice, through a prototype on the vehicle or beside the track, and on to volume. Each module includes documentation, an AT command set, an SDK, and sample code, with supply set for a build and for the long service life of rolling stock. As smart rail and vehicle-road coordination move forward, demand for these modules keeps growing, and the range will follow the radio technology operators actually adopt.
How a rail project usually moves
A rail communications project usually moves in this order:
The choice turns on onboard or trackside (a vehicle module has to take vibration), bandwidth (PIS and CCTV video need a wide pipe), handover across operators (a train crosses regions), and reliability (rail safety grades are high). Start on a single line and check how the module behaves in a tunnel and at speed. Onboard equipment and PIS should use 4G or 5G.
A connected railway can run more safely, serve passengers better, and maintain assets before they fail. SimtoLink has supplied modules to high-speed rail, metro, and urban-rail customers.