Li-Fi and its challenges to practical use

Wireless Internet powered by radio waves is one of two dominant ways people logon to the Internet, where the other approach is via wired Ethernet. More recently, a new approach for provision of wireless Internet through the encoding of information in light waves has emerged. Known as Li-Fi, wireless Internet is transmitted from light bulb capable of serving as a router, where information is encoded in light waves. Upon reception by a USB thumb drive with a light sensor, light waves could be decoded into useful information understandable by the computer. Demonstrated to be effective in transmitting information at a speed of 42 Mbps, which is equivalent to the upper speed limit of the HSPA+ wireless communication standard for mobile Internet, Li-Fi, nevertheless, faces severe challenges to its practical implementation. Specifically, information could only be reliably transmitted if there is reliable two way communication between light bulb router and USB transmitter. Thus, given that light travels in straight lines, Li-Fi could only be operative if the user is directly below a light bulb router, where the uplink from the USB transmitter to the light bulb router is through direct, straight line communication link powered by light waves, and reception could be through direct or reflected light waves (e.g., from the walls). Hence, Li-Fi is potentially more restrictive than wired Ethernet in terms of users’ movement. Additionally, demand for high speed wireless Internet would necessarily lead to higher light intensity used for information transmission. Thus, possibility exists where high intensity light could result in visual discomfort and heating effect to the users as a substantial amount of light energy would be converted to infrared heat. Collectively, practical application of the new communication protocol, Li-Fi, is hampered by basic issues of reduced mobility to users as well as a health concern such as to deem the approach untenable for broad adoption. Being a straight line communication tool between light bulb router and USB light sensor transmitter meant that the user is required to be under a light bulb or lamp during the entire duration of wireless Internet access, where he is likely to experience high intensity light waves for providing more bandwidth and wireless access speed that result in a heating effect.