Physics World August 2016
From WiFi to LiFi: Using light for wireless communication
In this month’s Physics World: A bright idea – using LED lightbulbs to create the next revolutionary wireless network
Harald Haas explains how the humble LED lightbulb could one day replace your WiFi router in this month’s Physics World.
Using light to transmit information is nothing new: from the use of beacons to communicate across long distances to the pulses that whiz down an optical fibre, light has been used as more than just a source of illumination for eons.
Now, Harold Haas and his team at the LiFi Research and Development Centre at the University of Edinburgh, UK, are developing a new way of using visible light to transmit data. Their technique means that every LED lightbulb, streetlight, headlight or lamp could one day become a wireless access point or router.
Global wireless connectivity currently relies on radio frequency transmission – frequencies that are low on the electromagnetic spectrum but which are becoming increasingly crowded with masses of data.
Haas and his team have proposed the idea of LiFi: using the visible part of the spectrum, to provide more frequencies to use to transfer data.
Haas explains: “The ubiquitous nature of light sources means that LiFi would guarantee seamless and mobile wireless services.
“A single LiFi access point will be able to communicate to multiple terminals in a bidirectional fashion, providing access for multiple users.”
Using LiFi could increase the amount of data that can be transferred at any one time: with so many existing light sources, the effective data rate delivered to a user of LiFi could be increased to around a gigabyte per second.
Other advantages of using LiFi networks include increased security: with light unable to pass through walls, access to networks can be more tightly controlled. LiFi networks would be more energy efficient too, as they can piggyback on existing lighting networks.
Also, because they do not need antennae to transmit signals, LiFi networks are much more suitable for hazardous working environments, such as petrochemical plants or oil-drilling platforms, where a spark from an antenna could be disastrous.
Haas concludes: “We need to stop thinking of light bulbs as little heaters that also provide light.
“In 25 years, my colleagues and I believe that the LED light bulb will serve thousands of purposes, not just illumination.”
But what are the challenges of using LiFi? If you want to read more about this revolutionary communications network, this article from Physics World is available in PDF form upon request.
Also in this issue:
• Features: How science is saving daguerreotypes – an early form of photograph – from decay
• News & Analysis: What Brexit could mean for the future of UK physics
• Features: Using neutron scattering to study crystal structure in the quest for new drugs
Access the August issue digitally now
Physics World Focus on: Vacuum technology
Challenges, applications and solutions
This special focus issue of Physics World explores the many fascinating applications of vacuum science and technology. Plasma processing is a strong theme this year, as we discover why tools and techniques developed as part of the boom in semiconductor fabrication are now benefiting biomaterials. Elsewhere, we reflect on the strengths of the vacuum community with outgoing IUVSTA president Mariano Anderle. And, as always, this vacuum focus issue provides a great chance to catch up with major industry players, including Pfeiffer Vacuum, Agilent, Honeywell and Edwards, to examine the latestinstrument upgrades and trends across the sector.