1. What a metro device sends over cellular
A smart metro covers train monitoring, platform doors (PSD), passenger services, and integrated O&M. Onboard terminals, trackside gear, and platform devices report over 4G or 5G. Tunnels and platforms mostly rely on a private radio system, and 4G fills the gaps. SimtoLink supplies 4G and 5G to metro operators, with a data pool and an API into the integrated O&M platform.
2. Trains, doors, passengers, and the control room
The line covers trains, platforms, passengers, and maintenance. Bandwidth, and how quickly an alarm has to land, differ by system:
Onboard monitoring and diagnosis
An onboard terminal reports running state, fault data, and video over 4G, for live monitoring, remote diagnosis, and fault warnings.
Platform doors and screen doors
A PSD controller reports open and close state and faults over 4G, for remote monitoring and a coordinated emergency response.
Passenger services and information
Platform displays, ticket machines, and gates report over 4G, for passenger counts, information display, and ticketing.
Integrated O&M and emergency command
Maintenance robots and inspection gear report over 4G, for emergency command, remote dispatch, and fault handling.
3. What the metro link has to cover
- Passenger information (PIS): Platform and onboard screens have to push arrivals, transfers, and emergency notices as they happen. That needs a steady, high-bandwidth link.
- Onboard video: HD cameras inside and outside the car send footage back live. AI looks for unusual behavior so the service stays safe.
- Integrated equipment monitoring: Traction, power, ventilation, and platform-door status come together live. A fault alert reaches maintenance staff within seconds.
- Automatic fare collection (AFC): Station AFC devices settle payments and report transaction logs as they happen, including mobile pay and face pay.
- A private network: A metro is critical city infrastructure. It needs a private LTE or 5G network, or a VPDN, and it has to meet MLPS.
4. Which SIM fits which system
Network, bandwidth, and power draw differ by system, so the SIM follows the device and the job. Use the table as a starting point:
| Use | Recommended network | Why it fits |
|---|---|---|
| Onboard PIS, announcements, and cameras | 4G/5G | Live content, video backhaul, and security monitoring |
| AFC fare collection | 4G+private network | Settlement, log reports, and remote maintenance |
| Station monitoring terminals | 4G/private network | Device status, fault alarms, and coordinated dispatch |
5. How much data a metro device uses
One device typically uses about 500MB–3GB a month, mostly video. Pool SIMs by device type, keep 20%–30% spare, and run a VPDN with MLPS.
6. Security for a public railway
A metro is public safety, so treat the link as extremely high security. It has to meet MLPS, on a VPDN, with China's commercial crypto algorithms and an IP allowlist. SimtoLink provides financial-grade protection and completes real-name registration for the SIMs.
7. What SimtoLink would put on the line
For onboard PIS, platform monitoring, and combined monitoring, use a 4G or 5G IoT SIM. Tunnel signal is weak, so the SIM has to be able to choose among operators. PIS and cameras need a large data plan. SimtoLink plans for 99.9% network availability, a choice of operators, a high-volume plan, and an API into the integrated O&M platform.
8. Opening a line
Take a metro rollout through these stages:
Pick the SIM by device type and check coverage on the target line. Set the VPDN or APN and the IP allowlist, and alert at 80% of the data allowance. SimtoLink stays with the project from the first station through opening day. Contact us for a plan built around that line.