In the recent blog posts we have already introduced the most common methods for indoor positioning: Wi-Fi and Bluetooth. Both are already being used in various scenarios and have proved to be successful. VLC (visible light communication) is a new, interesting method which is about to reach market maturity.
VISIBLE LIGHT COMMUNICATION – WHAT IS IT CAPABLE OF?
VLC can be used as a positioning technology, mainly for inside areas. Special LED and fluorescent lamps send out indiscernibly flickering light which can be detected by a smartphone camera or a separate photo detector, which is for example attached to a shopping basket. This enables for example indoor navigation (via app) and tracking (analysis of motion profiles via app). In the future, VLC could also be used for wireless internet connection.
Technically it works like that: Each lamp has its own ID which it compiles into pulsing light and sends to smartphones in the reception range. The app can access a map in which the lamps and their IDs are located. The incidence angle helps refine the position. Additional hardware such as beacons can fill in, where light doesn’t advance.
APPLICATION AREAS FOR VLC
VLC is suitable for all industries and use cases in which beacons are used. For example: supermarkets, shopping malls, DIY stores, airports, railway stations, hotels, gastronomy, parking garages, the health care sector, museums, trade fairs, office buildings and industry areas. A smartphone can determine its position via VLC (client based) – therefore and for having a back channel, an app is necessary. Thus, notifications (for example coupons) can be transmitted to the user. Server based tracking, which includes devices without app, only works with additional hardware in the lamp.
Specific use cases could be: Passengers can easily find their car in an airport parking garage with the help of an app and VLC. Customers of supermarkets are being navigated to the required products as the crow flies.
PROS & CONS OF VISIBLE LIGHT COMMUNICATION
- lamps are extensively and homogenously available in buildings
- beacons can complement positioning
- signals can easily be limited
- modern LED are energy efficient
- the positioning technology is not dependent on batteries
- VLC is precise (less than 1 meter) and has a high range (up to 8 meters)
- no disturbing, eye-catching, costly hardware
- works cross-platform
- draws on the reserves of the smartphone battery
- low flexibility when installing lamps
- most suitable for indoor installations
- high costs when modern lamps are already installed
- back channel and tracking only possible with special hardware/app