Emerging Application of Optical Wireless Communication Technologies in 6G Communication

Dear Colleagues,

While 5G technologies are rapidly being commercialized, with the first 5G networks being rolled out in 2019 and expected to be deployed around most of the world by the end of 2020, research on 6G is already underway, aiming to address the coming challenges regarding the drastic increase in wireless data traffic and support for other application scenarios. 6G is expected to extend 5G’s capabilities even further. There have been an increasing number of beyond 5G and 6G-related workshops and panels to obtain a consensus regarding the technologies that could make up 6G or the problems that 6G will solve.

The above developments create an increasing demand for a new spectrum, which extends to the optical spectrum for free-space communications. Fundamental issues such as higher system capacity, higher data rate, lower latency, higher security, and improved quality of service (QoS) are privileged areas of optical wireless communications (OWC) compared to radio systems. 

OWC technologies are envisioned for 6G communications in addition to RF-based communications for all possible device-to-access networks; these networks also access network-to-backhaul/fronthaul network connectivity. The FSO backhaul network is very promising for 6G communication systems, since data transfer in FSO systems is comparable with optical fiber systems. Hence, along with the optical fiber networks, FSO is an excellent technology for providing backhaul and cellular BS connectivity in 6G.

Moreover, OWC is not limited to backhaul use cases. It is greatly and increasingly considered suitable for mobile access networks, specifically low-latency, machine-type communications (such as car-to-car communications) beyond Gbps connectivity and up to Tbps for new mobile applications such as virtual and augmented reality. It is also considered for low-data-rate/low-power Internet of Things (IoT) applications and device-to-device communications. Artificial intelligence (AI) and machine learning (ML) techniques are now ready to pave the way for more efficient operation of wireless networks and enhance the overall user experience with new emerging applications that are expected to be implemented in 6G between 2027 and 2030. The transition from radio to subterahertz (sub-THz) and optical spectra (i.e., visible light communication) all-photonic radio access networks will constitute a new physical layer that is capable of accommodating all new services and applications envisaged for the 6G era.

In this Special Issue, we seek to explore emerging applications and technologies which will be suitable for beyond 5G and 6G and rely on OWC technology. We wish this Special Issue to offer an early platform to showcase and stimulate a lively debate on the 6G applications that OWC could support. We solicit and encourage researchers to present papers with original and recent developments covering various topics of interest that include, but are not limited to, the following:

• Vision, key drivers, new services and requirements for 6G
• OWC system and network architectures for 6G
• OWC backhaul and fronthaul solutions
• Spectrum and channel modeling for 5G and towards 6G
• Energy efficiency and harvesting technologies
• Multi-level machine learning pipelines in 5G and towards 6G
• Massive MIMO and beamforming techniques for 6G systems
• Propagation modeling on terahertz and optical spectrum
• Optical wireless biomedical applications
• Visible light communication systems
• Atmospheric optical wireless links
• Hybrid optical and RF/MMW links
• Channel coding techniques for 6G optical wireless systems
• Cooperative diversity techniques
• Adaptive optics
• 6G satellite communications
• 5G and beyond towards 6G testbeds and experimentation
• Security, secrecy and privacy schemes for 5G and towards 6G
• Distributed computing for 5G and towards 6G
• Quantum optics computing (QOC) and quantum Key Distribution (QKD) in 6G OWC systems
• Quantum optical networks and quantum machine learning in 6G
• Blockchain security and holography emerging technologies in 6G
• Smart grid, IoT applications, UxVs applications of OWC in 6G
• Mobile AI applications in 6G

We hope that this Special Issue will achieve a precise, concrete, and concise conclusion that contributes significantly to opening new horizons for future research directions.

Assoc. Prof. Konstantinos Peppas
Assoc. Prof. Hector E. Nistazakis
Assoc. Prof. Andreas D. Tsigopoulos
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Electronics is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.