4G refers to the fourth generation of cellular wireless standards. It is a successor to 3G and 2G families of standards. The nomenclature of the generations generally refers to a change in the fundamental nature of the service, non-backwards compatible transmission technology and new frequency bands.
So far there has been no specific definition to this successor of 2G and 3G. However it has been used often to denote a fast internet access available to mobile phone users. More over the distinguishing feature of high multimedia streaming and end to end IP configuration is judged to be its MAGIC enchantment.3G utilized WiMax and WiFi as separate wireless technologies, whereas 4G is expected to coalesce these two technologies. Hence one can evaluate how efficient it would become when combining two extremely reliable technologies. 4G can greatly anticipate in evolving and advancing the pervasive computing. The aim of pervasive computing is to attach itself to every living space possible, so that human beings remain intact with the wireless technology intentionally and unintentionally. Therefore 4G is be able to connect various high speed networks together, which would enable each one of us to carry digital devices even in dispersed locations. The network operators worldwide would be able to deploy wireless mesh networks and make use of cognitive radio technology for widespread coverage and access
Key enabler of 4G technology is Orthogonal Frequency Division Multiplexing (OFDM) and MC-CDMA (Multi Carrier CMDA). It will support IPv6 addressing scheme. It is designed in such a way that hundreds of parallel streams will be used simultaneously to send data. It will in effect increase the transmission speed to an unbelievable level.
Initially, 4G seems to be similar than wireless technology. But actually it is much more advanced. Many companies all around the world are working on it and planning to set the standards together. It is expected to launch sometime after 2010. It is predicted that 4G will have much wider bandwidth than earlier ones.
Presently, most of the people are using 2G technology (GSM) and very rapidly changing to 3G due to its super cool features of video downloading, video conferencing, anytime accessibility to news and information. 4G will have much more interesting features than 3G and it is in development phase now. It is supposed that 4G will have 100 Mbps data transfer speed in outdoor areas. For indoor, it is approximated as 1 Gbps.
The flexibility of 4G technologies to be used in combination with GSM and CDMA has provided it an edge over other technologies. The reason is that the high broadband capability of 4G not only increases data streaming for stationary users but also for mobile users.4G can be efficiently combined with cellular technologies to make consistent use of smart phones. The digital cameras attached in smart phones can be used to establish video blogs in scattered geographical regions. This gives the manufactures the opportunity to produce more affordable user friendly 4G compatible devices.