Experimental Demonstration of Vehicle to Road Side Infrastructure Visible Light Communications

The increasing use of light emitting diodes in traffic lights offer excellent opportunities for implementation of visible light communications (VLC) based wireless technology as part of intelligent transport systems in smart environments. In this paper, we experimentally demonstrate vehicle to infrastructure (V2I) communications based on the VLC technology using a real traffic light and a camera over a link span of up to 80 m. We show a reduction in the modulation depth of the signal from 1000% to 50% in order to track the light source when sending `0' symbols. Also presented is the effect of operating the camera in the focused and defocused modes. The results show transmission success rates of 100% and 90% over link spans of 70 m and 80 m, respectively under specific test conditions.