Mr. Sato’s letter about a design method of optical aggregation network was published in a journal of IEICE (in Japanese).

Title: A Design Method of High-Reliability and Low-Optical-Loss Optical Aggregation Network Using 2×2 Optical Switch
Authors: Takehiro Sato, Kunitaka Ashizawa, Kazumasa Tokuhashi, Daisuke Ishii, Satoru Okamoto, Eiji Oki, and Naoaki Yamanaka
Abstract: The Optical Aggregation Network is expected as a future energy-efficient network. This paper shows a novel optical switching network architecture for the Optical Aggregation Network that uses 2×2 optical switches. A performance estimation shows that the proposed architecture achieves both high reliability and low optical loss concurrently.

• IEICE Website

Ms. Yonezu’s paper about energy efficient network “MiDORi” was published in a journal of IEICE.

Title: Energy Optimal Topology Calculation Method for Self Organized Network MiDORi
Authors: Haruka Yonezu, Daisuke Ishii, Satoru Okamoto, Eiji Oki, and Naoaki Yamanaka
Abstract: In order to reduce the energy consumption of transport/data center networks, MiDORi network technology is introduced. This network is based on the concept of aggregating traffic into specific links, and powering off interfaces of routers/switches that do not convey traffic. In this paper, a practical energy-optimal topology calculation method is proposed for the MiDORi PCE. The proposal can adjust the link reduction rate and the calculation time by setting different values for the depth. Moreover, two failure management methods are proposed in order to reduce the risk of traffic aggregation. By computer simulation, it is shown that the proposed method is effective from several perspectives. Lastly, a prototype system of MiDORi network is described to observe the aspect of self organization.

• IEICE Website

Mr. Matsumoto’s paper about photovoltaic output power forcasting under smartgrid environment was published in a journal of IEICE.

Title: High Density Short-Term Forcasting Photovoltaic Output Power Architecture without Meteorological Observations in Smart Grid
Authors: Jun Matsumoto, Daisuke Ishii, Satoru Okamoto, Eiji Oki, and Naoaki Yamanaka
Abstract: We propose a forecasting architecture of near future photovoltaic output power based on the multipoint output power data via smart meter. The conventional forecasting methods are based on the analysis of meteorological observation data, and need the implementation of dedicated meters and the connection to them. Moreover, short-term forecasting is difficult in the conventional methods, since the short-term output power variation is irregular. Our proposed method is based on not meteorological observation data but the actual measured output power data by using the solar panels connected with a smart meter as sensing units. A forecasting calculation server interpolate spatially the actual measured data collected from multipoint, and forecasts near future output power in each point using optical flow estimation. Virtual sampling technique involves the forecast performance when the sampling point is sparse. We show effectiveness of the proposed forecasting method and improvement in forecasting accuracy with virtual sampling by the computer simulation.

• IEICE Website