For the last 20 years, ITU has been coordinating efforts of government and industry and private sector in the development of a global broadband multimedia international mobile telecommunication system, known as IMT. Since 2000, the world has seen the introduction of the first family of standards derived from the IMT concept.
International Mobile Telecommunications - 2000 (IMT- 2000) formed the basis for third-generation (3G) wireless systems, which consolidate yesterday’s diverse and incompatible mobile environments into a seamless radio and network infrastructure capable of offering a broad range of services on a global scale. Within the ITU, the radio aspects for IMT-2000, especially the selection of radio transmission technology (radio interface) and spectrum usage, are addressed in the ITU-R, whereas the network aspects, which include definition of network signaling interfaces, services, numbering and identities, quality of service and network performance, security, and operations and management for IMT-2000, are addressed by the ITU-T.
IMT(- 2000) represents the global standard for meeting the emerging needs of mobile telecommunications in the 21st century whereby mobile telecommunications subscribers are able to access voice, data, Internet, and multimedia services at any time and at any place . It is well recognized that international or global standards are needed not only to ensure seamless global mobility and service delivery across IMT-2000 family member networks, but also for integrating the wireline and wireless networks in order to provide telecommunication and information services transparently to the users.