No LED Performance Downside to LiFi, According to University of Edinburgh Researchers

According to research done at the University of Edinburgh with funding from the Engineering and Physical Sciences Research Council (EPSRC), found that LED lighting could help supplement wireless communications without affecting the quality of light. A team of researchers led by Dr. Wasiu Popoola concluded that transmitting digital data via LEDs while using them to produce light does not make the light dimmer or change the color of the LED bulb output. They also found that such communication known as Li-Fi does not make the LED bulbs consume significantly more electricity.

Dr. Popoola of the University of Edinburgh says these concerns have tempered the more popular adoption of Light Fidelity, or LiFi, in which household LED bulbs and luminaires can transfer data. According to these findings, the potential technical barrier that some believed might be a problem with LiFi, never actually existed.

Li-Fi has been seen by some industry insiders as a way to communicate data from connected, Internet of Things devices without clogging WiFi bandwidth.

Notably, preserving the quality of lighting is a vital consideration because it can have a significant impact on the physical and mental well-being of people in their homes and workplaces. Although it has long been known in the lighting industry for some time that LEDs can be ‘piggy-backed’ to broadcast data to and from tablets, mobiles, sensors, and other devices, lighting industry insiders still had questions about the ability of the LED lights to act as transmitters without reducing their money-saving and ‘green’ benefits.

Encoding with On/Off switching or tiny changes in light intensity

The Edinburgh team focused on warm and cool white LED bulbs that used two primary data transmission methods. One method uses very rapid on and off switching that is picked up like morse code despite being imperceptible to human eyes. The other method that the group studied uses continuous signaling in which imperceptible changes in light intensity are coded to achieve the same type of data transmission.

Neither LiFi transmission method was found to significantly reduce the brightness of the LED bulbs or their expected useful life. The group also found that neither technique caused any significant change in the color of the LED bulb’s output. Also, both communication processes produced only a negligible difference in the heat generated by the LEDs. This temperature change is a fundamental factor in terms of performance. Any temperature increase would mean that the LED bulbs had to use more electricity to produce light, making them less energy-efficient.

Dr. Popoola added, “Our ever more connected world will need more bandwidth than the overcrowded Radio Frequency part of the spectrum can provide. Plugging a key knowledge gap, our results are very encouraging for the future of light-based communications that could help realize the full economic and social potential of a wireless future. It’s vital that LED manufacturers know what impact the incorporation of data transmission capabilities would have on their products. Our research shows that there’s no dark side to using LED lights to supplement WiFi.”

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