As LED becomes increasingly widespread, Microsoft Research has also caught on with LiFi technology developments with proposed LED positioning system, Epsilon. The company’s Asia research division recently published a paper explaining the concept behind the positioning system.
According to the company’s website, the LED positioning system uses “Binary Frequency Shift Keying (BFSK) and channel hopping to enable reliable location beaconing from multiple, uncoordinated light sources over the shared optical medium." The researchers have implemented the Epsilon system and evaluated it with a small scale hardware test bed as well as moderate-size simulations.
Experimental results of Epsilon: the 90th percentile accuracies are 0.4 meters (m), 0.7m and 0.8m for three typical office environments. Even in the extreme situation with a single light, the 90th percentile accuracy is 1.1m.