In recent years, we have witnessed a staggering growth of mobile data traffic due to the widespread use of wirelessly connected Internet of Things (IoT) devices. It is forecasted by Cisco that the overall mobile data traffic is expected to grow to 77 Exabytes per month by 2022, a seven-fold increase over 2017, while more than 70% percent of the mobile data traffic will take place in typical indoor environments. Due to the nearly exhausted radio frequency (RF) spectrum resource, it becomes challenging to support the ever-increasing mobile data traffic using conventional RF technology.

As an emerging technology, optical wireless communications and networking (OWCN) has attracted tremendous attention due to its inherent advantages such as a license-free spectrum, large capacity, high security, and no electromagnetic interference. OWCN can be implemented by using various wavelength regions including infrared (IR), visible light (VL), and ultraviolet (UV), and can be applied in various scenarios including indoor, outdoor, and underwater environments. Nevertheless, the massive deployment of OWCN systems faces several key challenges such as high transmission rate, low energy consumption, low latency, smooth handover, blocking and mobility, and flexible/robust system design.

The present Special Issue aims to attract contributions from all areas of OWCN and publish high-quality research articles as well as review articles that seek to address the challenges of future deployment of OWCN systems.

Potential topics include but are not limited to the following:

• Novel electrical or photonic devices and components for OWCN
• Advanced modulation, coding, equalization, and detection
• Multiple-input multiple-output, multiple access, and multi-user scheduling
• Multi-cell/cellular network design, handover, and interference mitigation
• Channel modelling, characterization, and measurement
• Transceiver nonlinearity, characterization, and compensation
• Hybrid and duplex system design, and resource allocation and management
• Artificial intelligence/machine learning-enhanced OWCN
• Visible light communication (VLC) based positioning, ranging, detecting, and sensing
• OWCN for indoor, outdoor, underwater, vehicular, and IoT applications