LiFi (Light Fidelity) is a multi-gigabit wireless technology using visible light communications (VLC). You can read more about on how these work in Secret Of LiFi .
Below are 8 of the more interesting uses where LiFi could really shine:
Underwater: Traditional underwater communications use either sound/acoustical waves or RF signals. Both of these have limitations in water which greatly reduce their data carrying capability. Light wave based communications with LiFi can achieve higher data rates over longer distances. Light may also be friendlier to the environment and sea animals than sound.
Military Outposts: Since LiFi signals are easily contained by walls or even black-out fabric, this is a good choice for localized secure communications. Military camps and bases would not need to install wiring, nor would they have to guard against WiFi snooping.
Hospitals: Other security conscious locations, hospitals and medical facilities could use their light systems for passing patient information and medical status. This could also be used to provide internal GPS signals with on-screen maps so that patients, visitors and staff can navigate large facilities and campuses. Hospitals also benefit from LiFi since most medical equipment can be cease to work properly in the presence of WiFi and Cellular signals.
Museums: Rather than Bluetooth or WiFi, museum could use LiFi to provide information about exhibits.
Stores: Similar to museums, retail markets could provide product information, coupon codes and other personalized shopping experiences. Consumers may prefer LiFi in this case to Bluetooth or WiFi since it allows them to remain anonymous by only receiving data. With LiFi, there is no need to broadcast your information, so the merchants are not able to track you.
Vehicles: The head-lights, tail-lights and turn signals can be purposed to provide vehicle to vehicle communications. Cars could share data about traffic conditions and emergency vehicles could announce their presence. “Amber Alerts” would no longer be confined to lighted street signage, but sent directly to your in-dash info-trainmen the system. With autonomous vehicles become more prevalent, a vehicle communications infrastructure will be needed. Similar to airplanes, it may not be long before each car transmits its own identification as it drives along the road. This could be as simple as it’s license plate number, the manufacturer VIN or some variation with additional information.
Municipalities: Imagine how your local city or town could use street lights and traffic signal lights to send information to your vehicle as you drive. You car could then upload this to your smartphone for you to read later.
Harsh Environments: In many places, a WiFi or Cellular signal could cause a catastrophic event. Military ammunition facilities ban communications devices out of caution of accidentally triggering an explosive. The inside of a tanker ship transporting natural gas is another place where an electro-magnetic / RF signal could cause an explosion. Similarly, oil refineries and nuclear power plants have wide ranging bans on anything which emits an RF signal.
You can learn more about VLC and Wireless Communications in these books we suggest from Amazon:
Visible Light Communication by Shlomi Arnon (Editor)
Wireless Communications by Andreas F. Molisch
Wireless Communications by Andrea Goldsmith