LiFi doesn’t affect LED performance, says research

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Energy-saving LEDs could help meet demand for wireless communications without affecting the quality of light or environmental benefits they deliver, according to research funded by the Engineering and Physical Sciences Research Council.

A University of Edinburgh team has found that transmitting digital data via LEDs at the same time as using them to generate light does not make the light dimmer nor change its colour. Neither does it make the LED any more energy-hungry. Dr Wasiu Popoola of the University of Edinburgh, pictured, who led the research, says these concerns have held back the more widespread adoption of LiFi.

The research findings could help to eliminate key hurdles to using LEDs for wireless communications. Although it has long been known that LEDs can be used to transmit data to and from mobiles, tablets, sensors and other devices, questions have remained about whether this affects the LED’s ‘green’ benefits.

Focusing on LEDs producing ‘warm white’ and ‘cool white’ light, the Edinburgh team looked at two data transmission techniques: on-off keying, where the LED works like Morse code; and continuous signalling, which uses imperceptible changes in light intensity.

Neither technique was found to reduce the lightbulbs’ brightness or life expectancy significantly, or to cause any significant change in the colour of the light. Both techniques also produced only a negligible change in the heat generated by the LEDs.

Dr Popoola noted: “Plugging a key knowledge gap, our results are encouraging for the future of light-based communications. 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.”