Preface Ryoji Chubachi Chairman of the Board Radio systems in the field of telecommunication and broadcasting, as seen in mobile phones, wireless access, ITS, RFID, digital broadcasting, etc., have been more and more sophisticated and diversified with the recent rapid advances of digital technologies. They are expected to grow as an infrastructure that supports economic activities and social lives as well as creates a new culture. Further expansion in use of radio is expected to contribute, with digital technologies, to further development of a relieved, safe and convenient ubiquitous network society. In addition, international cooperation to establish common worldwide standards for radio systems has become important for research and development (R&D) and standardization of new radio systems. ARIB was designated as "the Center for Promotion of Efficient Use of Radio Spectrum" and "the Designated Frequency Change Support Agency" by the Minister of Internal Affairs and Communications (MIC) under the provisions of the Radio Law. Under the designation, ARIB conducts studies and R&D, establishes standards, provides consultation services for radio spectrum coordination, cooperates with other overseas organizations and provides frequency change support services for the smooth introduction of digital terrestrial television broadcasting. These activities are conducted in cooperation with and/or with participation by telecommunication operators, broadcasters, radio equipment manufacturers and related organizations as well as under the support by MIC. I hope that our activities will benefit promotion of public welfare through the use of radio systems. I appreciate your further support and cooperation.