Physical Layer Security in Visible Light Communication

The 6G lays the foundation for a new wireless communication technology 1000 times more capable than 5G in terms of speed and information transfer capacity. This new technology which enables information transfer via light and is called “Visible Light Communication,” will soon become a significant part of our lives. A research project coordinated by Professor Dr. Erdal Panayırcı, a Faculty Member in the KHAS Department of Electrical-Electronics Engineering, focuses on this new technology.

The amount of information generated by people increases by 1000 times every decade, and this rate of growth persists for the past 50 years without any change. However, it’s understood that this will further accelerate as inorganic objects, which are expressed as “things” specifically in the area of communication and start to generate information and communicate with each other.

It’s required that a new G (generation) communication technology which is 1000 times more capable than the previous generation, must be developed every decade for such a large size of information to be securely stored, processed, and transferred from one place to other. Starting with 1G in the 1980s, we’ve gradually reached 5G this year, approximately five decades later. Applications such as “Virtual and Augmented Reality,” “Communication Between Machines and Tools,” “Self-Decision-Making Systems via Artificial Intelligence and Machine Learning,” “Big Data Markets” in which we struggled to achieve superior performance until now will add new dimensions to and provide convenience for our daily lives with the 5G technology in the next decade.

Stating that new capabilities to be provided by 6G technology to be launched in the early 2030s will be characterized by science-fiction and believing that intensive scientific research and development studies on 6G, which have already started, will achieve this goal within ten years, Prof. Dr. Erdal Panayırcı, a Faculty Member in KHAS Department of Electrical-Electronics Engineering, explains the most significant difference between 5G and 6G as follows: “5G technology is largely based on the technologies that have been developed gradually from 1G to 4G. Until now, we haven’t come across several specific and new technologies that will need to be created with the 6G. With the 5G, we’ve reached the end limit of the frequency of the electromagnetic waves we use to transfer information. As an alternative and supporting way to do this, the 6G lays the foundation for a new wireless communication technology 1000 times more capable than 5G in terms of speed and information transfer capacity. This new technology, which enables information transfer via light and is called “Visible Light Communication,” will become a part of our lives like our mobile phones.

This new technology to make a breakthrough in the wireless communication technology soon also forms the main interest area of a significant research project: Coordinated by Prof. Panayırcı, the TÜBİTAK ARDEB 1003 (Program for Supporting R&D Projects in Primary Areas) project titled “Physical Layer Security in Visible Light Communication,” is intended to design and verify a unique and innovative physical layer security system in the lab environment for ensuring security in VLC. To this end, developing security software and hardware platform forms the primary goal of the project.

Optical Wireless Communication (OWC) systems and Visible Light Communication (VLC), an application of it, provide crucial technical and operational superiorities in a wide range of applications due to very high-frequency bandwidth, information transfer capacity, immunity against electromagnetic interferences, high rate of safe shut-down in spatial environments, and the fact that its spectrum of frequencies is regulated via specific regulations. We find it as new technology that is an alternative for radio-based wireless communication systems based on 5G and beyond, or a new complementary technology to be used frequently and considered a standard.

As conveyed by Prof. Panayırcı, VLC systems are based on light-emitting diodes (LEDs). These are still among the most researched systems and draw the most attention among new and next-generation broadband technologies. Operating with a vast range of frequency bands such as 400-800 THz (780-375 nm) and speeds such as 100 gigabytes/second (Gbps), VLC will facilitate the application of systems beyond 5G and will make outstanding contributions accordingly.

Executed by Prof. Panayırcı, the project has a total of 10 people: 2 master’s degree students from KHAS work as scholarship students and contributes to required work packages. One professor is assigned to the project by Istanbul Technical University; 1 professor makes contributions externally. One undergraduate and one doctoral student continue their project studies as scholarship holders. One professor is assigned to the project as research by Bosporus University, while one doctoral student and one undergraduate student continue their project-related studies as scholarship holders.

For the international part of the project, the eponym of the project named “Visible Light Communication,” Prof. Harald Haas from Edinburgh University (UK), serves as an official consultant for the project. Also, two students who continue their doctoral studies under the management of Prof. Haas after completing their master’s study at Kadir Has University support the project. Finally, we must indicate that Prof. Vincent Poor from Princeton University (US), who has excellent physical layer security experience, also supports the project.

Started on November 15, 2019, and to continue for two years, the project is related to the NEWFOCUS coded COST (The European Cooperation in Science and Technology) project on optical communication and completed within the period from September 1, 2020, to September 1, 2024.

Regarding the project, articles were published in scientific magazines with high impact factors, and the results of the studies were presented in international conferences until now. The team attained the first positive results about the project hardware, and a patent application is planned to be made very soon. Also, a master’s student graduated by completing the master’s thesis related to the project. Other master’s and doctoral students continue their studies successfully.