The purpose of this Recommendation is to present an overview of the radio subsystem for IMT-2000 and give guidelines for the development of the structure of the radio sub-system. The radio sub-system includes the functionalities needed to provide IMT-2000 services over a radio interface(s) to mobile terminals in all IMT-2000 operating environments, as defined in Recommendation ITU-R M.1034 on Requirements for the radio interface(s) for International Mobile Telecommunications-2000 (IMT-2000).