The current Wi-Fi network use Radio Frequency waves, but the usage of the available RF spectrum is limited. Therefore a new technology, Li-Fi has come into picture. Li-Fi is a recently developed technology. This paper explains how array of LEDs are used to transmit data in the visible light spectrum.
In 2006, the view was that WiMax mobile networks might not be launched until the end of 2007 or 2008. It would then take some time to install the networks and require terminal devices, so it might not be until 2010 that it would be likely to see whether WiMAX was having any impact on 3G, on the other hand, some straightforward observations propose that its impact will be bounded to some limits.