A new study funded by the Engineering and Physical Sciences Research Council (EPSRC) has revealed that energy-saving Light Emitting Diodes (LEDs) could help meet the demand for wireless communications without disturbing the quality of light or benefits they offer.
Dr Wasiu Popoola. Credit: Engineering and Physical Sciences Research Council (EPSRC)
A team from the University of Edinburgh has found that transmitting digital data through LEDs at the same time as employing them to produce light does not change the color of light or make the light dimmer. Nor does it turn the LED into more energy-hungry. Dr Wasiu Popoola from the University of Edinburgh, who headed the research, said that these concerns have restrained the more widespread adoption of Light Fidelity, or LiFi, which employs household LEDs to allow data transfer.
However, these findings help remove key hurdles to employing LEDs in order to help satisfy the growing global thirst for wireless communications. Particularly, preserving the quality of lighting is an essential consideration as it can have a major impact on the mental and physical wellbeing of people in both their workplaces and their homes. In recent years, LEDs have secured a massive increase in their share of the global lighting market and they are being employed extensively in TV and other displays.
Although it has been known for some time that LEDs can be ‘piggy-backed’ to broadcast data to and from sensors, mobiles, tablets and other devices, still questions have surrounded the LEDs’ ability to do this without affecting its core capabilities or the ‘green’ or money-saving benefits that make them very popular.
Focusing on the ‘warm white’ and ‘cool white’ light produced by LEDs, the Edinburgh team studied two different data transmission methods: on-off keying, where the LED functions like Morse code, switching on and off very quickly and imperceptibly to the human eyes; and continuous signaling, where imperceptible changes in the intensity of light are employed to achieve the same goal.
Neither method was found to considerably reduce the brightness or life expectancy of the lightbulbs, or to make any vital change in the color of the light. Both methods also made only a negligible change in the heat produced by the LEDs – a key concern as any increase in temperature would indicate the LED employing more electricity to generate light, making it less carbon-friendly and less energy-efficient.
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.
Dr Wasiu Popoola, The University of Edinburgh