Over the last 25 years, ITU has developed the IMT framework of standards — or International Mobile Telecommunications system — for mobile telephony and continues to lead international efforts involving governments and industry players to produce the next generation standards for global mobile communications.
Since 2000, IMT-2000 has been widely deployed and referred to as 3G. ITU has now announced the next-generation of standards for global wireless broadband communications, known as IMT-Advanced. Following a detailed evaluation against stringent technical and operational criteria, ITU has determined that "LTE-Advanced" and "WirelessMAN-Advanced" should be accorded the official designation of IMT-Advanced. The detailed specifications of IMT-Advanced technologies will be provided in a new ITU-R Recommendation expected to be announced during the Radiocommunication Assembly meeting in Geneva, 16-20 January 2012.
IMT-Advanced systems include the new capabilities that go beyond IMT-2000. They provide access to a wide range of telecommunication services supported by mobile and fixed networks, which are increasingly packet-based.
IMT-Advanced systems support low to high mobility applications and a wide range of data rates in accordance with user and service demands in multiple user environments. IMT-Advanced also has capabilities for high quality multimedia applications within a wide range of services and platforms, providing a significant improvement in performance and quality of service.
For research purposes, the target transmission rates for IMT-Advanced was set at 100 Mbit/s when used in a high mobility environment (e.g. driving in a car) and 1 Gbit/s in a stationary environment.
The term 4G remains undefined but it is being applied by operators to the forerunners of IMT-Advanced technologies — LTE, HSPA+ and WiMax and to other evolved 3G technologies, which provide a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed.