An overview of third-generation wireless personal communications is presented, and the challenges to meet its demands are examined. At the ITU level, the third generation is known as IMT-2000.(1) In Europe, the third generation of wireless personal communications is known sis UMTS. Special attention has been paid in giving a brief description of the research and development, standardization, and regulatory activities. The UMTS Terrestrial Radio Access (UTRA) concept is presented. The different ACTS projects involved in making UMTS a success are introduced.