LiFi (optical wireless transmission, light fidelity) enables mobile communication with light. LiFi is used as a complement to radio, where higher user density requires more capacity. Moreover, LiFi fulfills special safety and electromagnetic compatibility requirements. Nowadays, a LiFi cell has 1-10 m diameter and delivers data rates from 100 Mbit/s to 1 Gbit/s. LiFi is based on commercially available high-performance LEDs, which are also used for lighting, and large-area photodiodes. Technology and costs are similar to those in radio: orthogonal frequency division multiplexing (OFDM) and adaptive transmission are used as well as multiple-input multiple-output (MIMO), relay function and handover between adjecent access points.
The Fraunhofer HHI has developed LiFi from its basics, is contributing to standardization and supports its transfer into applications. Pilot projects are currently taking place with end users in real operating environments.
- High data rates and large coverage
- Robust against electromagnetic interference
- Improved privacy
- No interference with existing WiFi networks
- Mobile access in RF sensitive areas (e.g. hospitals)