‘Internet of Light’ integrates enlightenment, communication and ministry

When it comes to efficiency and quality, light-emitting diodes (LEDs) are the MVP of lighting technology today. A team of Chinese researchers is using recent improvements in LEDs as a springboard to launch a more interconnected lighting network.

In their study published on September 30, 2022 in Intelligent and converged networksthey proposed the concept of an Internet of Light that interfaces with the Internet of Things to improve human health and well-being by providing information services.

“As people spend more and more time indoors, there is a dire need to provide a lighting network that offers smart lighting as well as information services by combining information technology with communication technologies,” said Jian Song, professor of electronic engineering at Tsinghua University.

Since LED is silicon-based, it can facilitate the deep integration of lighting networks with different electronic and intelligent control mechanisms at low cost. In addition to lighting control, researchers from the fields of information and communication technology (ICT) have demonstrated the feasibility of so-called visible light communication (VLC), which transmits information by modulating the luminous intensity of the LEDs. This form of communication could simultaneously support information services such as location, data transmission, and even optical therapy without causing eye strain or damage.

“Rapid advancements in the related fields of ICT and humanities have motivated us to come up with the idea of ​​Internet of Light (IoL) as a platform and develop its key features,” Song said.

To integrate IoL into ubiquitous lighting networks, researchers combined sensors, communication modules, and smart processing units in individual LED lights to form a “node” and adopted telecommunication technologies, such as power line communications (PLC) and 5G wireless communications as means of networking.

An IoL sensor network consisting of specially designed detection nodes can collect information such as light intensity, color, hazardous gas level, moving objects, etc.

Applications for this type of IoL include “smart” nursing homes where a resident can be located for safety and security or a cooking gas leak can be detected in time. Automatic light intensity or color adjustments can customize a comfortable environment according to user preference or as a means of conducting optical therapy.

To support these features effectively and efficiently, researchers developed algorithms and conducted hardware experiments to demonstrate system performance for high-speed data delivery. This included experimenting with a real-time beam-aligning VLC design that can quickly adjust the direction of the emitting light source based on the user’s position.

Researchers studied the optimization of resources under different constraints such as communication and location services to allocate different frequencies and powers, as well as communication and lighting to meet various lighting requirements including intensity and uniformity.

“As communication and positioning services will be provided by lighting networks, optimizing power allocation is essential,” said Hui Yang, professor of electronic engineering at Tsinghua University.

To support applications such as video transmission and real-time positioning, researchers are exploring scheduling algorithms that can meet the stringent timing requirements of a base station and minimize latency.

Previous studies have demonstrated that light can be used to treat certain dermatoses or neurodegenerative diseases, showing the possibility of non-intrusive optical treatment. The team explored this possibility by designing a light stroboscopic irradiation experiment with a flickering frequency of LED light.

“Preliminary results of our investigation confirmed the relationship between light stimulation and human reaction by electrodermal activity signal and other methods,” said Xiaofei Wang, a professor of electronic engineering at Tsinghua University. “This demonstrates that an IoL platform can potentially regulate human emotions and brain activity by controlling the light source flicker frequency intelligently and automatically.”

In the next steps, the researchers plan to integrate individual technologies into an environment like a nursing facility, which could benefit from intelligent sensing, communications and optimization under resource constraints, according to the study.

The combination of lighting and environment creates a highly interactive, complex and dynamic system with huge gaps and diversity for individuals,” said Luoxi Hao, a professor at Tongji University College of Architecture and Urban Planning. “The benefits of real-time perception, instantaneous response and seamless interconnection of information supported by IoL can certainly play an important role in realizing a human-centric lighting concept.”

Provided by Tsinghua University Press