ZetaDisplay enables real-time urban communication powered by the Com4 mobile network

Solutions

ZetaDisplay uses Com4 SIM cards in all displays where Wi‑Fi or fiber is not available. The mobile network becomes the secure, always‑on link between each screen and the cloud-based CMS, Engage Suite.

Each display setup includes a Windows-based PC, an industrial 4G modem and sensors that track temperature, brightness and humidity. As soon as the screen is powered on at the customer site, it connects to the cloud and downloads or streams the content automatically.

For Ruter, this enables each screen to show real-time information based on the GPS position of buses, trams and subways. Data is continuously fetched from Ruter’s systems and appears on the screens within seconds.

The value of this approach became clear during the pandemic. With 4G connectivity, Ruter could instantly push infection-control information and dynamic updates across the entire public transport network—something that would not have been possible with older 2G technology.

“As long as we have an online connection, we can access any screen directly to troubleshoot, test and update software without sending a technician. This is crucial when you have thousands of devices in the field,” says Lysholm.

All communication is protected with VPN and encryption, so the screens can be remotely monitored and controlled without compromising security.

Results

The partnership between ZetaDisplay and Com4 delivers clear benefits for both operators and passengers:

- Real-time control: Traffic information on the displays is updated within seconds via the cloud.

- Reliable in demanding environments: The cellular network keeps screens online even where fiber is not available.

- Fast, simple installation: No digging or cabling required – the display goes live as soon as the SIM is activated.

- Full remote management: Testing, software updates, and troubleshooting are all handled remotely.

- High security: VPN and encrypted communication meet strict requirements in transportation, banking, and healthcare.

- Signage as a Service: Stable connectivity enables a predictable, service-based model with uptime at its core.

Next step: eSIM for even better control

ZetaDisplay now sees eSIM as the next step. With eSIM integrated into the hardware, each display gains a more flexible backup connection – whether the primary access is fixed line or Wi‑Fi.

Looking ahead, we see eSIM as the next step to secure even more seamless backup and communication. With continuous network access, we can rule out errors faster and gain better control of our devices,” says Lysholm.

For public transport to run smoothly, passenger information must be reliable.

When screens are deployed across the city – without fiber, without Wi‑Fi, and without on-site follow-up – Com4’s mobile network is what keeps everything connected.