A perspective on the evolution of mobile communications

This article outlines the current state of mobile communications and presents some of the future directions in research and development from the perspective of NTT DoCoMo with special emphasis on the market in Japan. It first describes the directions in which mobile communications are expected to forge ahead in the future, and the service implementation strategies they could employ. Then it describes an example of mobile multimedia services and present an outline of the Freedom of Mobile Multimedia Access (FOMA), which is a service based on the 3G mobile communications system called International Mobile Telecommunications-2000 (IMT2000). This is followed by an overview of our R&D approach to 4G systems, which constitute mobile communications systems of the future, and the profile of technologies to make these happen. Finally, it reviews our approach to future technologies that are expected to be realized in 4G and subsequent systems, and illustrate it with an example of a research project.