What is VLC?
Visible light communication (VLC), also known as LiFi, is the utilisation of light as a means of data transmission, providing both lighting and high speed wireless access. VLC technology effectively converts every LED light bulb into a wireless access point.
How does VLC work?
In a VLC system, data is transmitted by modulating the intensity of the LED light, which can be then recovered by a photodetector. This modulation is performed in such a way that it is not perceptible to the human eye and does not have any adverse affect on lighting quality.
If low data rate applications are targeted, a smartphone camera can be also used as a receiver. Such systems are referred to as optical camera communication (OCC).
Applications of VLC
Indoor High Speed Internet Access
Operating at optical bands with large bandwidth capacity, VLC is a powerful alternative to WiFi at home and office for an enhanced user experience. In particular, VLC provides a superior performance over WiFi in user-dense environments such as coffee shops, airports, libraries, etc. It can be also utilized as a complementary technology where excess capacity demands of cellular or WiFi networks can be offloaded.
Outdoor Hot Spots
Outdoor lighting such as street lamps and building lights can be used to provide VLC hotspots for pedestrians.
Intelligent Transportation Systems
Considering the fact that LEDs are becoming very common in automotive lighting and the roadside infrastructure, i.e., street lamps, traffic lights, VLC is a natural candidate for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications.
Hospital & Healthcare Facilities
Unlike radio frequency (RF) communication systems, VLC systems operate at optical frequencies and emit no electromagnetic interference. Therefore, they can be safely deployed in hospitals and healthcare facilities without any concerns on possible interference to medical instruments including MRI scanners.
VLC systems operate at optical frequencies and can be utilized in RF restricted environments such as mines and petrochemical plants.
Via the LED reading lights, VLC technology can be used to provide wireless access to airline passengers. It can be further integrated with in-flight entertainment (IFE) systems to reduce the associated cabling.
Location Based Services
Each LED light can be used as a beacon to transmit highly accurate location-specific information. This can be used for personalized advertising, indoor navigation and precision inventory tracking.
Underwater acoustic communication systems can support long range links, but can achieve only a few tens of kilobits per second (kb/s) failing to support high data rates. Underwater VLC systems can achieve data rates up to hundreds of megabits per second (Mb/s) and are particularly attractive for short and medium range link
The information received from LED lights can be augmented to real life images to enhance user experience.
Standardization of VLC
802.11.bb Light Communications Task Group
IEEE 802.15 WPAN™ Task Group 13 (TG13) Multi-Gigabit/s Optical Wireless Communications
ITU-R SM.2422-0 Visible light for broadband communications