Modelling of Road Lighting in Connection with VLC Requirements – Case Study

The article follows on from the article presented at the LS17 conference entitled "Case study – Modelling of Visible Light Communication (VLC) on Luminous Intensity Distribution Curve (LIDC) of LED Low Beam Car Headlamps". This post dealt with the possibility of using VLC on roads with road lighting systems. In particular, it addressed the minimum light levels at which VLC can still be operated in the outdoor traffic area. These have been compared to the illuminance levels that can be achieved using LED low beam cars headlamps. It was mainly about the distance in front of the car at which it is able to distribute a useful VLC signal. The post addressed whether this technology is even possible to implement in relation to the distances that cars need to stop safely [1]. Since road lighting is also part of the night-time traffic space in cities and towns, this article will deal with its possibilities for implementing VLC in relation to the car communication with this infrastructure. This is made possible by the fundamental expansion of LED technologies, which have already penetrated not only light sources in automotive, but also road lighting [1]. The existing lighting systems of road lighting did not allow the application of VLC, because they were dominantly fitted with high-pressure sodium discharge lamps, which did not allow even slow regulation of the luminous flux, let alone fast switching (modulation) of the luminous flux at kHz levels and above. To demonstrate the possibilities of road lighting, a standard LED lighting system of road lighting with low levels of requirements according to European road lighting standards [EN 13201-2 Road lighting - Part 2: Performance requirements] and classification M5 was chosen for modelling.