It describe wireless mobile radio technologies that offer faster data rates than current 3G (third generation) technologies. 4G networks are also more data-centric and based on standard Internet technologies such as IP. Voice service is typically provided using a special form of VoIP..
WiMAX and LTE are examples of 4G technologies.
A 4G system will be able to provide a comprehensive IP solution where voice, data and streamed multimedia can be given to users on an “Anytime, Anywhere” basis, and at higher data rates than previous generations.it is expected that end-to-end IP and high-quality streaming video will be among 4G’s distinguishing features.
4G is being developed to accommodate with forthcoming applications like wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV, HDTV content, Digital Video Broadcasting (DVB) etc.
The fourth generation cannot be an incremental evolution of current 3G technologies, but rather the total replacement of the current 3G networks and handsets. The international telecommunications regulatory and standardization bodies are working for commercial deployment of 4G networks roughly in the 2012-2015 time scale. At that point it is predicted that even with current evolutions of third generation 3G networks, these will tend to be congested