ITU-R The ITU-R Recommendations constitute a set of international technical standards developed by the Radiocomunication Sector (formerly CCIR) of the ITU. They are the result of studies undertaken by Radiocommunication Study Groups on: – the use of a vast range of wireless services, including popular new mobile communication technologies: – the management of the radio-frequency spectrum and satellite orbits; – the efficient use of the radio-frequency spectrum by all radiocommunication services; – terrestrial and satellite radiocommunication broadcasting; – radiowave propagation; – systems and networks for the fixed-satellite service, for the fixed service and the mobile service; – space operation, Earth exploration-satellite, meteorological-satellite and radio astronomy services. The ITU-R Recommendations are approved by ITU Member States. Their implementation is not mandatory; however, as they are developed by experts from administrations, operators, the industry and other organizations dealing with radiocommunication matters from all over the world, they enjoy a high reputation and are implemented worldwide. ITU-R Reports contain technical, operational or procedural statements prepared by a Study Group on a given subject ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three Sectors of the International Telecommunication Union (ITU). ITU-T was created on 1 March 1993 within the framework of the "new" ITU, replacing the former International Telegraph and Telephone Consultative Committee (CCITT) whose origins go back to 1865. The ITU-T mission is to ensure an efficient and on-time production of high quality standards (Recommendations) covering all fields of telecommunications except radio aspects. Standardization work is carried out by 13 Study Groups, in which representatives of the ITU-T membership develop Recommendations for the various fields of international telecommunications. The priority fields of study include: IP interworking and related matters Network aspects of mobility Network access technologies (xDSL) Optical networking technologies Tariff and accounting issues Multimedia services and systems ITU-T standardization activities are conducted in cooperation with many other standards development organizations (SDOs).