From pneumatic tubes to a 5G campus

On the premises of Salzgitter Flachstahl GmbH, steel capsules speed through tubes at seven meters per second. They contain material samples that need to be sent to the lab for quality assurance. Until now, there has been no suitable digital replacement for pneumatic tubes, an analog technology that has worked reliably for decades. 

Transmitting digital data within a plant is a different story: At Ilsenburger Grobblech GmbH, another company in the Salzgitter Group, cranes transmit process data to control systems, cameras provide real-time images for remote control, and employees record warehouse data on mobile tablets. This requires bandwidth, low latency, and a connection that won’t drop out even in a steel factory building where temperatures reach up to 80 degrees Celsius. Wi-Fi reaches its limits in such environments—and the public cellular network is often insufficient on sprawling industrial sites.

Salzgitter Digital Solutions GmbH (SZDS), the Salzgitter Group’s central IT service provider, is therefore taking a new approach by setting up the Group’s own 5G campus networks. These are not just a vision of the future on PowerPoint slides, but a functioning infrastructure in active production facilities.

Christian Kühlen, Head of Industrial Communications at SZDS, is the person responsible. His department handles everything related to radio transmission and reception within the company—from telecommunications and radio remote controls to messaging technology. “You could say we’re the handymen of SZDS,” says Kühlen. 

Kühlen found the answer in Ilsenburg, at the feet of the Harz Mountains in Saxony-Anhalt, where Ilsenburger Grobblech GmbH manufactures heavy steel sheets under extreme conditions—the most demanding environment imaginable for radio technology. Together with its technology partner Cocus AG, SZDS initiated a proof of concept—a structured field test under real production conditions—at the end of 2025.

More money than a 5G campus network, in any case. SZDS funded most of the field test itself—at a time when the industry’s economic situation was not exactly conducive to investing in new technologies. Word quickly spread throughout the Group that the concept was working. Even before the proof of concept in Ilsenburg was officially completed, for example, Peiner Träger GmbH, also a subsidiary of the Salzgitter Group, came forward with a concrete order.

The real star of the SZDS approach is not the technology, but the scaling model. The central core system—essentially the brain of the 5G network—will be operated at the SZDS data center in Salzgitter. “We are a group and we have a data center,” says Kühlen. “It would stand to reason to make a one-time, centralized purchase of the expensive core system for a campus or a connected area and then to make it available to all the companies located there.” From the core, additional locations could be connected via fiber optic cables without each subsidiary having to build its own core infrastructure. The costs would be shared among all participating companies, and the initial and ongoing costs would be significantly lower for each additional location.

Kühlen is following a pragmatic principle here: a 5G campus network is always set up where a specific use case justifies its implementation—not as a one-size-fits-all solution for an entire plant at once, but rather in a modular, scalable manner that is tailored to actual needs. The group companies receive everything from a single source: SZDS plans the infrastructure, procures and installs the hardware, configures the network, integrates end devices and applications, and handles day-to-day operations. “As a rule, we do everything,” says Kühlen. “Either on our own or with partners.” The technology works, and the results speak for themselves—with each new location, the network grows, and so does the Group’s expertise.