Driverless transport systems, conveyor belts, engines, robots, sensors, drones, mobile terminals, a wide variety of machines and systems - they all communicate with each other in the Industry 4.0 factory floor, exchange vast amounts of data. They are often mobile components, which makes wireless networking indispensable. But WiFi and Bluetooth only offer limited bandwidth, and the increasing number of users renders the radio spectrum overcrowded. Although 5G is expected to alleviate this problem, the challenges of communication in production environments can be overcome more effectively without a license-free technology.
Researchers at Fraunhofer IOSB-INA in Lemgo (Germany) are therefore taking a different approach: they chose the visible spectrum of light for wireless data transmission. Visible Light Communication (VLC) is what experts call the technology. "The light spectrum is about 4000 times wider than the entire available radio spectrum, ranging from 380 to 800 nanometers wavelength," says Fraunhofer scientist Daniel Schneider. Together with colleagues and the Technical University OWL, he is working on the project "Visible Light in Production" to make VLC fit for the requirements of industry.
Compared to WiFi, VLC offers a number of advantages. It offers a higher bandwidth; data security is also guaranteed: Radio signals penetrate walls, so communication can be intercepted and manipulated outside the factory floor. This is not possible with light. Another bonus: 1000 or more devices will be able to be networked wirelessly with each other via VLC. "Once we have optimally designed our VLC system on the basis of our measurement campaign, we will be able to operate more than 1000 devices at one location - energy-saving, tap-proof and insensitive to electromagnetic influences," summarizes the researcher. In addition to the ceiling lighting, the system requires only an Internet access and a transceiver that is connected to the terminal device. The researchers have developed a demonstrator that is currently being tested in the Lemgo SmartFactoryOWL under real-world conditions. Both large and medium-sized companies are