The proliferation of wireless devices in the upcoming evolution of 5G will have a profound impact on the communications industry. Wireless traffic will also surge due to the increasing per-device data demand from novel services and applications. These changes to the wireless communications landscape are driving the demand for ultra-dense wireless network deployments. In recent years, this demand has led to a growing interest in optical wireless (OW) networks as a novel solution. Researchers have shown promising data rates for OW communications via Infrared (IR), visible light communication (VLC), and ultraviolet (UV) technologies. These high data rate capabilities coupled with the directionality of the optical medium allow OW small cells to provide very high bandwidth density (b/s/m2). Accordingly, densely distributed OW small cells have the potential to provide additional wireless capacity in the indoor environments where it is needed most.

Compared to traditional RF networks; these OW deployments can provide very high aggregate capacity; however, densely distributed OW small cells are challenged to accommodate highly dynamic environments. Specifically, the OW channel is susceptible to blocking and the smaller coverage region of each cell implies that devices with high mobility will change connections frequently. In order to mitigate the impact of these limitations, heterogeneous networks (HetNets) have been proposed where OW networks supplement traditional RF small cell networks – combining the aggregate capacity gains of the former with the coverage and reliability of the later. These Coexisting Radio and Optical Wireless Deployments, or CROWD networks, are of high interest as we look for new ways to accommodate the demand that will be placed on next generation wireless networks.