Fraunhofer IPMS in Dresden Germany will present Li-Fi communication modules at the 2018 Optical Fiber exhibition & conference OFC in San Diego from March 13 to 15. In competition with Wi-Fi industrial solutions, wireless optical technology promises faster, interference-free and more secure infrastructures.
In recent years, Wi-Fi has become increasingly important in both private as well as highly-automated industrial environments. In the age of digitalization demanding ever larger amounts of data to be transferred, the installation and maintenance of wired networks have become more and more complex. Because wired systems such as Ethercat or Profibus cannot be used everywhere, wireless systems are often more suitable, especially for moving equipment or mobile machinery. Many wireless technologies such as Wi-FI, however, quickly reach their limits in environments with multiple network partners. These technologies are often too slow and susceptible to interference, making it difficult to reliably transmit security applications with fast cycle times over Wi-Fi in large industrial environments. Because radio signals can penetrate walls as well as machine casing and can be heard over foreign receivers within range, Wi-Fi also poses serious questions with regard to privacy issues.
Able to transfer data via light, Li-Fi (light fidelity) technology solves many of these problems. »Li-Fi makes use of the globally unregulated spectrum of light,« explains Fraunhofer IPMS Chief Developer Dr. Alexander Noack. »Limited only by the opto-electronic components selected for modulation or demodulation, the available bandwidth of this spectrum allows for extremely high net data rates.«
The system also features real-time capability. Noack continues, »Wi-Fi provides packet-based, asynchronous data transmission. In contrast, Li-Fi allows to send data continuously in a stream. Li-Fi therefore provides reliable operation for applications in which data calculation and transmission are not allowed to exceed a predetermined time limit. Several data links can be parallelly built in spatial multiplexing so that no interference between individual data links exists, enabling a very high density of transmission cells to operate in an interference-free industrial environment.«
Li-Fi technology is bound by the one basic requirement that data transmission only works when the visual axis between the transmitter and receiver is free and clear. This is an extremely important advantage from a security standpoint. Because light cannot penetrate walls or other obstacles, foreign actors outside are unable to access and record data being transmitted.
Testing conducted under real-world conditions is often the only way to determine whether Li-Fi offers a viable an alternative for a specific application. Fraunhofer IPMS offers customers its Li-Fi HotSpots evaluation kit. Optical data links can be set up at a data rate of 1 Gbit / s over a distance of five meters. The module can be simply integrated into existing systems via a CAT5 cable. Point-to-point connections can be built in half- or full-duplex mode. Depending on the application, the size, data rate, transmission distance and interfaces of the Li-Fi HotSpot can be optimized and further developed according to specific customer requirements. USB 3.0, Ethernet and Gigabit-Ethernet interfaces have already been implemented in industrial applications. Point-to-point, point-to-multipoint or multipoint-to-multipoint connections may also be used. In addition, Li-Fi technology may be applied in moving or rotating systems, wherever the use of cable, slip rings and connectors is limited and in situations demanding large amounts of data such as video to be transmitted for process control.
Visitors to 2018 OFC are invited to the Fraunhofer IPMS exhibition at Booth 5901.
Fraunhofer Institute for Photonic Microsystems