Abstract :
It has been already 12 years since we had the last VTC conference in Tokyo, Japan. In that year 2000, total number of digital mobile subscribers in the world was 663 million with 2nd generation systems, while currently, it has exceeded 5 billion. During the last decade, we have enjoyed tremendous evolution of mobile communications in terms of subscriber numbers and technologies. Diversified services are now available from voice, video and Internet. Thanks to novel technologies, packet data rate has been increased by 1000 times during the last decade drived by the demand of wireless applications by smartphones. And still, mobile data traffic will grow at a compound annual growth rate (CAGR) of 200 percent per year in Japan and in other major countries resulting into 1000 times in the next decade. To cope with this high volume traffic, innovative technologies of radio-access, system and network should be furthermore developed.