Oct 13, 2017: A team of researchers at the University of Edinburgh, UK, did a year long research to find out if Li-Fi could be detrimental to the energy-efficiency of LEDs used as lighting sources. The research has been funded by the Engineering and Physical Sciences Research Council (EPSRC).
The researchers explained their project in a paper title “A Study of the Impact of Visible Light Communications on the Quality of Lighting and Display.” They found that LEDs could help meet demand for wireless communications without affecting the quality of light or environmental benefits they deliver.
The study shows that when digital data is transmitted through LEDs at the same time when it is being used to generate light, does not make the light change its colour, or become dimmer. nor does it make the LED consume more energy. Preserving the quality of lighting is a key consideration as it can have a major effect on the physical and mental wellbeing of people at homes and at workplaces.
According to Dr Wasiu Popoola, lead researcher at the Li-Fi R&D Centre and Institute for Digital Communications, University of Edinburgh, these were the major concerns that the industry had, and which held back consumers from using LiFi in combination with household LEDs. It also hampered widespread adoption of Li-Fi.
The researchers looked into LEDs that produce warm white and cool white light with the help of two different data transmission techniques—first, on-off keying, where the LED works like Morse code, which switches on and off rapidly and imperceptibly to human eyes; and second, continuous signalling, where changes in light intensity are used to achieve the same goal.
Both the technique were found to be successful and none significantly reduced the LED light bulbs’ brightness or their life expectancy, neither did they cause any significant change in the colour of the light. Both techniques produced only a negligible change in the heat generated by the LEDs. Heat generation is another key consideration as any temperature increase would indicate the LED is using more electricity to produce light, making it less energy-efficient and less carbon-friendly.
Dr Popoola adds, “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 realise 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”.