A Guiding Light

Light Goes from Illumination to Communication

Light_communications_lVisible Light Communication (VLC) is a method of pumping out binary messages using light. Light waves can be flashed in such a way that the human eye isn’t bothered, but a smartphone or tablet can perceive and decipher the code. VLC is a complement and sometimes competitor to radio frequency waves, and is being standardised within the IEEE’s Wireless Personal Area Networks working group. Here come the implementations.

Philips and French retailer Carrefour are trialling the use of VLC to create an interactive in-store experience, using special LED bulbs to track shoppers and present them with product information and special offers. Users are required to install a smartphone app that utilises the phone’s front-facing camera to detect light flashes, and the app can also provide indoor navigation by picking up location information from the lights. Philips says the technology can provide location fixes with sub-metre accuracy.

This is Philips’ first live trial of its LED-based indoor positioning system, and it comes as retailers are evaluating the use of beacons and other technologies to enhance the in-store shopping experience. Other tracking solutions use Bluetooth or Wi-Fi. The company’s timing could be fortuitous, with retailers looking to retrofit linear fluorescent lights with energy efficient LED bulbs.

Philips isn’t alone in developing lighting systems that enable live shopper interactions. Earlier this month, General Electric announced a partnership with Qualcomm to develop advanced VLC bulbs for accurate data transmission and location triangulation. The collaboration marks support from the leading light bulb manufacturer and the wireless telecommunications giant to push VLC as a mainstream communications channel.

The long life and ubiquity of LED bulbs means low installation and maintenance costs for retailers, but these VLC solutions don’t yet provide the same bidirectional communications abilities of Bluetooth-based beacons. For now, it’s likely that light alone won’t be enough to satiate retailers’ strategies to track and interact with their consumers.

Last year, CCS Insight wrote about the use of an optical wireless communications method called Li-Fi (see Daily Insight: Light Support). Li-Fi uses light waves for high-bandwidth, bidirectional communications: data rates have reached 10 gigabits per second under optimum circumstances, and even indirect light can support transfer rates of up to 70 megabits.

The omnipresence of smartphones in developed markets and the introduction of smart, LED-based lighting systems are enabling a new type of communications. Lights are switched on and off in nanoseconds, creating signals that only machines can see. In a radio spectrum crunch, VLC can become a useful complement. Light can go a long way.

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