Hiroshi Esaki, Ph.D, received the B.E. and M.E. degrees from Kyushu University, Fukuoka, Japan, in 1985 and 1987, respectively. And, he received Ph.D from University of Tokyo, Japan, in 1998. In 1987, he joined Research and Development Center, Toshiba Corporeation, where he engaged in the research of ATM systems. From 1998, he works for University of Tokyo as an associate professor, and works for WIDE project as a board member. He has been at Bellcore in New Jersey (USA) as a residential researcher from 1990 to 1991, and has engaged in the research on high speed computer communications. From 1994 to 1996, he has been at CTR (Center for Telecommunications Reserch) of Columbia University in New York (USA) as a visiting scholar. He is currently interested in a high speed internet architeture, including MPLS technology, a mobile computing, and IPv6.