Theterm “4G” refers to the fourth generation of wireless cellular standards. It is the successor of the second and third generation groups of standards. Overall, the number of generation means a fundamental change in service principles which does not have backward compatibility with the previous technologies and frequencies.
The first generation 1G standard appeared as a definition of analogous network in 1981.
The 2G communication standard was registered in 1992, being a system with channel commutation (the most common type of 2G networks is GSM).
This standard was later developed to support multimedia services with a minimum data transfer rate of 200 kbit/s in 2002, partially retaining the channel commutation principle and receiving the name of 3G.
Soon, the term 4G appeared, standing for a network with full packet commutation based on IP protocol and multi frequency data transfer method that provides mobile access at a rate of up to 1 Gbit/s.
Review
4G systems are expected to be a comprehensive and safe solution based on IP protocol which allows users to use such services as telephone, high-speed Internet access, multimedia streaming etc.
Overall, the term “4G” is defined by the IMT-Advanced standard, which is registered by International Communication Union Radio communication Sector (ITU-R).
Information about the standards
In September of 2009, proposals on accepting the 4G standards were submitted to the ITU-R. They were generally based on the following two technologies:
- 802.16m (Wimax), accepted as a standard in IEEE
- LTE Advanced, standardized in 3GPP
MobileWimax
The IEEE 802.16e-2005 standard, commonly known as MobileWiMAX, is a description of mobile broadband wireless access that provide speak data transfer rates of 128 Mbit/sfor receiving and 56 Mbit/sfor sending traffic with channel width of 20 Mhz.
This standard is at the stage of development to the level of IEEE 802.16m which complies with the IMT-Advanced criteria, where the bit rate provided for stationary users is up to 1 Gbit/s, and up to 100 Mbit/s for mobile users. The first implementation of MobileWimax in the world was accomplished under the WiBro brand in Seoul, South Korea on June 30, 2006.The first commercial MobileWimax network was launched under the AERO brand in Karagandy, Kazakhstan on December  9, 2008 года.
More information (Wikipedia)