You arrive at the supermarket in a hurry with a list of things to buy for a kid’s birthday party. Fortunately you’ve got your shopping list saved in an app on your phone. It immediately generates a map showing you the quickest route around the store to pick up everything you need. It guides you around the aisles with a moving arrow on a map.
With your phone’s help, you’ve found the paper plates, but the ones you want aren’t on the shelf. You use the app to call a shop assistant, who fetches the missing item from the stock room.
Now you’re dithering in front of the soft drinks display. Your phone buzzes and you receive a special offer nudging you towards a particular brand. Decision made.
Lights that talk
All of the above is now possible. And believe it or not, it’s all thanks to LED lights.
The technology is called visible light communication (VLC) and it works by encoding data into the light from normal LED luminaires. It’s not as crazy an idea as it might sound, because, although it may not look like it, any LED light is actually flashing on and off very fast. The human eye can’t see this invisible flicker, but a digital camera, like the one in your mobile phone, can. So it’s not too big a jump to vary the flicker in a way that’s still not visible to the eye, but that turns the flicker into a digital signal.
You don’t even need special lights to do this: you just need a specially programmed driver, so in theory it should work with pretty much any LED luminaire. This also means it’s not as expensive to implement as you might think (at least, that’s what the people selling it say).
Data in light
The most obvious application for VLC is to create a light-based alternative to Wi-Fi, known as Li-Fi. You can also use it to link data to illuminated objects, as Japan’s Fujitsu has demonstrated. Point your phone at an item lit by Fujitsu’s spotlight and the camera reads data in the reflected light to provide you with information about the item.
Where it’s at
But the application of VLC that is taking off the fastest is indoor positioning.
All you have to do is tell every luminaire in a space to send out a unique identifying signal, over and over again, and when your smartphone sees which lights are nearby, it can pinpoint its location with astonishing accuracy – to within about 10cm. That’s way more accurate than GPS, which has never worked very well indoors anyway.
It’s not hard to see why retail is the number one sector that providers of VLC-based positioning systems have their eye on. Customers are already using their phones in shops and retailers are desperate to connect with them. Retailers already have digital maps of their stores and diagrams of what goes where on the shelves, ready to be integrated with a positioning system to create powerful interactive maps. Imagine the difference it could make in vast ‘big box’ retail outlets, sprawling shopping malls or multi-floor department stores.
The video below show Gerben van der Lugt of Philips demonstrating the company's indoor positioning at Light + Building last year. ‘We see a lot of applications from retailers to bring location-based services to their shoppers: on-shelf or near-shelf couponing, product finding...bringing relevant information to the shoppers when it really matters,' van der Lugt says.
Philips Lighting is trialling a positioning system at a museum in the Netherlands (see box, above) and hopes to apply the technology to retail applications too.
Lighting electronics specialist EldoLED has been running a large-scale trial of its Lux Award-winning positioning system with a US retailer, and is working on live installations for two retail clients.
US startup Bytelight is combining VLC-based positioning with Bluetooth, so that lights can communicate with smartphones before customers have even taken them out of their pockets. A test installation at Green Apple Books in San Francisco features luminaires with Bridgelux Decor Series LED modules and built-in Bluetooth, and Bytelight is working on other trials that combine this with VLC.
GE Lighting has two trials of positioning systems underway with retailers in Europe, and two more in the US. It’s looking at applications including navigation and delivering coupons. Like Bytelight, GE’s approach is to combine VLC with other technologies built into luminaires, such as Bluetooth and cameras – drawing on the company’s expertise in areas outside lighting.
Mike Barrett, who is in charge of product management for GE in EMEA, believes indoor positioning is a ‘game changer’. ‘Retailers are constantly challenging us to think about new, creative ways of helping them,’ he told Lux. ‘They’re not just asking how we can help them from a sustainability point of view, but how we can help them reduce their costs and improve their revenue.’
A further advantage of positioning systems is the intelligence they will be able to gather. When you shop online, every click you make is tracked and analysed, your buying habits memorised, and all the numbers crunched to make sure sites offer you what you’re most likely to buy. But in the bricks-and-mortar world, where most purchases still take place, it’s much harder to research what shoppers do and why. Indoor positioning promises to bridge that gap, bringing together the best of both worlds.
Steve Lydecker of EldoLED’s parent company Acuity Brands says: ‘What we’re seeing is retailers moving beyond the traditional values of light in terms of quality and energy efficiency... and focusing more now on new features that can come from the intelligence that’s embedded in their lighting systems. It’s about adding that internet-style shopping experience to purchases made in the physical environment.’
So what kinds of services can we expect to see? Well, that’s up to the retailer. They can integrate the technology with their own apps, websites and store systems. And from the kinds of apps they’re already using (see box, left), the potential benefits are clear.
All the richness, intelligence and connectivity of the online world is about to be blended with the real world. And – who would have thought – it’s all thanks to the lighting.