Fraunhofer IPMS: Li-Fi meets augmented reality

Developers at Fraunhofer IPMS use visible or infrared light to send and receive data. Transmission takes place without contact, in real time, at very high data rates. Optical communication, Li-Fi (light fidelity) is particularly advantageous in applications in which cables and connectors can interfere, or wireless radio networks such as WLAN or Bluetooth reach performance limits in terms of bandwidth or real-time capability. Data glasses or "augmented reality glasses" fall into this category. Visitors to the 2019 embedded world Exhibition & Conference, being held from 26-28 February in Nuremberg, can experience the possibilities of optical wireless data transmission in an augmented reality scenario at the Fraunhofer IPMS Booth 123 in Hall 3.



In addition to the perception of the real environment, augmented reality (AR) glasses provide the user supplemental information faded into or laid over their field of view. Such glasses are used in areas like warehousing and logistics, assembly and product development, or medical technology. Depending on the application, large amounts of data need to be transferred and interactive content resulting directly from a user's actions must be available in a certain period of time.

Because cables restrict movement and users of mobile applications typically need to have their arms free, wireless data transfer techniques are preferably installed in AR glasses. The usual standards such as WLAN and Bluetooth are, however, limited in bandwidth and not designed for real-time transmission. Dr. Alexander Noack, Development Manager at the Fraunhofer IPMS says, "Data glasses are a great example of the benefits of our Li-Fi technology. Optical wireless transmission offers high constant data rates, low latency, and maximum user mobility. It combines the flexibility of wireless solutions with the benefits of cabled transmission and provides even greater bandwidth than radio-based solutions."

As long as there is a clear visual axis between the transmitting and receiving modules, optical data transmission can be used wherever connectors, cables, sliding contacts, and radio networks need to be replaced.  At this year's embedded world Exhibition & Conference, Fraunhofer IPMS will be demonstrating how Li-Fi can support augmented reality applications at Booth 123 in Hall 3. The demonstrator to be used is based on an optical data link with a data rate of 1 Gbit/s over a distance of 5 meters. It is also available as a Fraunhofer IPMS Customer Evaluation Kit. The module can be simply integrated into already existing systems via a CAT5 cable. Depending on the application, the size, data rate, transmission distance and interfaces of the "HotSpot" can be further developed and adapted according to customer-specific requirements. Distances of up to 30 meters and data rates up to 1 Gbit/s can be applied depending on the ambient conditions. Interfaces such as USB 3.0, Ethernet, and Gigabit Ethernet have already been implemented.

To evaluate other applications, Fraunhofer IPMS conducts regular Li-Fi hands-on workshops. The workshops provide participants the opportunity to build Fraunhofer IPMS modules and to test the limits of the technology with regard to their own ideas and products.


Image: Shuttershock / Fraunhofer IPMS