Implementation of a Hybrid Optical-RF Wireless Network with Fast Network Handover

Visible light communication (VLC) is a highly attractive choice for short-range communications, particularly in indoor scenarios. There are many reasons for this mainly, high achievable data rates, no interference to existing radio frequency (RF) systems, security and most importantly, an increasingly pervasive lighting infrastructure based on solid-state lighting. But there is an inherited challenge that light-based communication links need strict line-of-sight (LOS) and can easily be blocked. Researchers are proposing to exploit this property to make atto-cells in pico and micro-cellular architectures for indoor communications. Therefore, this technology seems promising to play its part in a heterogeneous environment. The proof-of-concept for such hybrid systems capable of vertical handover (VHO) between two technologies is of great value. In this paper, we present implementation details of a hybrid communication system which can efficiently monitor its primary link, i.e., VLC link and quickly switch to radio frequency (RF) whenever VLC link is failed. We define our decision-making and link-monitoring scheme in between network and data-link layers of communication protocol stack. To the best of our knowledge, this novel implementation allowing a fast handover is the first of its kind in the field of hybrid optical-RF systems.