Summary This Recommendation defines the objectives to be met by IMT-2000 and provides the overall IMT-2000 concepts with particular consideration to achieving worldwide roaming and compatibility. This Recommendation provides a high level statement on the topics of: services@ architecture@ network aspects@ implementation@ sharing and operational characteristics. Guidance is provided@ for a limited number of possible scenarios@ on spectrum bandwidth and band of operation based on critical technical parameters and traffic estimates. It forms a foundation for the subject of IMT-2000 and for the subsequent work activities and Recommendations.