Applying VLC in 5G Networks: Architectures and Key Technologies

Visible light communication has gained tremendous attention recently and has become a favorable complementary technology to millimeter- wave communication in short-range communication scenarios for future 5G networks. VLC possesses a number of prominent features to address the highly demanding 5G system requirements for high capacity, high data rate, high spectral efficiency, high energy efficiency, low battery consumption, and low latency. These prominent features include but are not limited to abundant license-free spectrum, the ability to provide multiple gigabit-per-second data rates, low energy consumption, and low implementation costs. In this article a heterogeneous multi-layer 5G cellular architecture with a control plane and user plane separation scheme is presented. Three layers — the macrocell layer operating below 3 GHz, the picocell layer operating in the mmWave spectrum, and the optical attocell layer operating at the visible spectrum — are considered in this architecture, with each layer targeting a different coverage and communication need. We further address potential solutions for uplink communications, backhaul connections, and downlink communications in an optical attocell. Several key technologies employed in VLC downlink communications, including modulation, multiple access, and error control schemes, are also discussed.