Using visible light links in combination with radio communication in a vehicular network

In VANET networks using TDMA access it is possible to approach the full capacity of the channel when the density of vehicles increases. When this occurs, some vehicles will be unable to communicate with the rest of the network. The use of Visible Light Communication (VLC) for certain vehicles can reduce the load on the radio channel and allow all vehicles to communicate on the network. The idea of our approach is to group vehicles with VLC capacity in platoons where only the lead vehicle would use radio transmission while the other vehicles in the platoon would communicate via the VLC system. We show that if the vehicles are randomly equipped with VLC transmission capabilities (with a probability p), the gain in bandwidth is significant even without rearranging the order of the vehicles. In this paper we estimate the performance gains obtained by using VLC in terms of bandwidth and probability of collision during an initial access.