Feature topic: Visible light communications [Message from the Editor-in-Chief]

The April 2015 issue is published with mainly two sections. The first section is a Feature Topic (FT) entitled ???Visible Light Communications,??? co-edited by Nan Chi, Harald Haas, Mohsen Kavehrad, Thomas DC Little, and Xin-Lin Huang, who are experts working in visible light communications (VLC) for many years. VLC indeed has attracted much attention recently in the wireless communication community due to the fact that the visible light spectrum offers a lot of untamed free bandwidth, which can be used to provide ultra-fast speed wireless communications. On the other hand, radio spectrum has been extremely scarce and it is extremely difficult to squeeze out more useful bandwidth for futuristic high rate wireless communications. Although we do notice that VLC may not be best suited for large cell based mobile communication purposes, it can serve as an important supplementary to be used for small cell wireless coverage as hot spots under large heterogeneous networks. It has been demonstrated that VLC can enable wireless communications easily up to several Gbps, which can play an extremely important role in 5G and beyond wireless communications. Therefore, the publication of the papers included in this FT is timely and, hopefully, will become an important reference source for those working in this exciting research area.