Notices of the growth of electric power consumptions in communication networks issued before now become big issues for sustainability, related on Sustainable Development Goals (SDGs) 7/9/11/13 due to tremendous use of a lot of information locally/globally, which is produced/ created, transferred, processed and compiled anytime anywhere. For further reduction of power consumption, several technical challenges are under research/developing; Smart devices/ modules/ subsystems that use Silicon Photonics (SiPh), Photonic Integrated Circuit (PIC), Co-Package Optics (CPO) are current key technologies. However, as power consumption (e.g. in a system) is simply expressed by the notation of P [pJ/bit] x S [bit/s] x N where P; per device power, S; speed, N; the total number of devices (in a system), not only device enhancement but network architecture enabling to use much smaller number of devices (smaller N) have to be researched.

This article discusses the network configuration of wavelength routing networks with hierarchical structure in terms of wavelength, together with different type of router elements so far considered, then discusses the possibility to accommodate virtualized network functions (VNFs).

Kimio Oguchi received the B.E. and M.E. degrees in applied physics and Dr. Eng. degree in electrical engineering in 1978, 1980 and 1995, respectively from Nagoya University, Nagoya, Japan. 

He joined NTT Public Corp. (now NTT), Japan in 1980. Since then, he was engaged in the R&D and its management of fiber-optic systems including pioneering passive optical LAN and proto type of PON system, and multi-band WDM systems. He was also involved in the standardization activities in both ITU-T SG’s 13 and 15. 

Then, he moved to academia in 2004 as a Full Professor at the Information Networking Laboratory, Graduate School and Science and Technology and Faculty of Science and Technology, Seikei University, Tokyo, Japan, researched sensor-based networks and its applications. In 2019, he moved to NTUST as a Project Professor at the Department of Electrical and Computer Engineering, NTUST, Taipei, Taiwan. 

He was also serving as the director of SAXA Holdings Japan during 2015 to 2019, Inc. and is currently serving as the outside director of TAMA-TLO Ltd. Japan. 

He has organized a lot of international conferences/symposiums, especially dedicating the Secretary as a founding member of OECC for more than 30 years, an active steering member of FOAN (Fiber-Optics in Access Networks), and a chair of IEICE-HiSiPIC collaborative workshops.

His research interests include information networking issues, applications utilizing e.g. photonic networks, cyber physical systems, sensor networks, and human vital functions, and contents distribution networks.