Power systems for telecommunications in the IT age

Public telephone network have been dramatically changing to IP (Internet protocol) based network. This paper starts with an overview of the present status of the telecommunications network and the rapid evolution of IDCs (Internet data centers) now underway. Next, we focus on the existing configurations and the characteristics of power systems for IP equipment and IDCs, and then clarify the cutting-edge technologies for highly reliable powering systems and the advantages of DC power systems. Finally, the paper demonstrates the energy saving and environmental protection activities being implemented by NTT Facilities, and the prospected issues to be solved in the field of power systems for the coming full-fledged IT Age.