February 2011 Vol. 9 No. 2

Front-line Researchers

• Hiroshi Saito, Senior Distinguished Researcher, NTT Service Integration Laboratories

  

  Researching What Should Be Researched

  Overview
  Hiroshi Saito, an NTT Senior Distinguished Researcher, was the first in the world to propose Interdisciplinary Network Science as a field that attempts to systematically bring together existing traffic theories. We asked him about the present state of traffic research and the future outlook for this field.

Feature Articles: Environment and Energy Technologies Toward a Green Society

• Environment and Energy Technologies Toward a Green Society

  

  Abstract
  This article provides an overview of NTT Energy and Environment Systems Laboratories’ research and development (R&D) objectives and initiatives to move the country toward a green society. Our ambitious R&D agenda is based on three key concepts—Green ICT, Green materials, and Governance by Green—with the goal of completely eliminating CO₂ emissions and waste generated by the NTT Group’s business activities by the year 2050.

• Higher-voltage Direct Current Power-feeding System

  

  Abstract
  In this article, we introduce activities aimed at spreading the use of higher-voltage direct current (HVDC) power-feeding systems. We introduce the state of development of HVDC systems, improvements in operability, and standardization trends.

• Recent Activities Concerning NTT Technical Requirements for Electromagnetic Compatibility

  

  Abstract
  In this article, we describe the backgrounds of and present summaries of the revisions to the technical requirements for electromagnetic emission and resistibility to overvoltage and overcurrent. We also summarize the newly published technical requirements for electromagnetic emissions from lighting equipment installed in telecommunication centers.

• Energy Network Optimization Technology

  

  Abstract
  Energy network optimization technology achieves operational control and system construction for purposes such as reducing the environmental load by efficiently matching energy demand and supply from numerous facilities. This article describes demonstrative optimal scheduling research and a system configuration simulation as applications of this technology.

• Development of SOFC Power Generation Module with High Electrical Generation Efficiency

  

  Abstract
  This article reports on the development of a 3-kW class solid oxide fuel cell (SOFC) power generation module being developed jointly by NTT, Sumitomo Precision Products Co., Ltd., and Toho Gas Ltd. as an industrial stationary power generation system. NTT has been developing cell materials, anode-supported cells, and SOFC stack technologies. The 3-kW class SOFC power generation module uses two 40-cell SOFC stacks. This module provided long-term and maximum electrical efficiencies of 56% and 59%, respectively.

• Anti-corrosion Technologies for Telecommunications Structures and Equipment

  

  Abstract
  In this article, we introduce research on anti-corrosion technologies with a focus on outdoor telecommunications facilities and equipment. This research is proceeding in two ways: by understanding individual corrosion mechanisms for metallic materials at the microscopic level and by rapidly visualizing corrosion risks from the macroscopic viewpoint. We explain these two approaches and present the latest research results.

• Algorithm for Estimating Resource Input in ICT Industry

  

  Abstract
  We present an algorithm for estimating the input resources consumed in managing equipment used in the information and communications technology (ICT) industry. It helps to produce appropriate plans for avoiding rising procurement costs and reducing the environmental impact of ICT equipment, which will enable us to prepare for the increase in the cost of resources caused by their depletion.

• NTT Group Energy Efficiency Guidelines Initiative and Promotion of Green R&D

  

  Abstract
  In April 2010, the NTT Group Energy Efficiency Guidelines were created with the goal of reducing the NTT Group’s energy costs as well as its environmental load. The guidelines establish evaluation methods and set target standards for power-consumption efficiency in information and communications technology (ICT) equipment. They were accompanied by revisions to the “Detailed Guidelines for the Green Assessment of R&D Results”, which is part of the NTT Group Green R&D Guidelines. This article introduces the background and current state of this series of initiatives.

• Quantifying Environmental Load Reduction Effect of Utilizing ICT

  

  Abstract
  This article describes our methodology for assessing the environmental impact of information and communications technology (ICT) and reports on international standardization activities regarding ICT and the environment.

Regular Articles

• Optical Control of Nanomechanical Vibration in GaAs Resonators

  

  Abstract
  Vibrational control in GaAs micromechanical cantilevers through optical carrier excitation has been demonstrated. With laser irradiation to [110]-oriented cantilevers at near-band-gap wavelengths, the quality factor increased with increasing laser power, whereas shorter-wavelength irradiation decreased the quality factor. The opposite laser power dependence was observed for [-110]-oriented cantilevers (90° different). These results indicate that the control of the quality factor is due to the piezoelectric stress generated by optically excited carriers. This is a new method of controlling nanomechanical vibration in micromechanical resonators, which does not need any cavities or feedback circuits.

• Ray-tracing-based Technique for Reducing Computational Complexity of MIMO Propagation Channel Estimation

  

  Abstract
  When radio areas or systems in wideband wireless communication systems are being planned, a multiple-input multiple-output (MIMO) propagation channel must be considered. This article introduces a technique based on ray tracing that reduces the computational complexity for estimating the MIMO propagation channel. This technique can estimate the MIMO propagation channel without any increase in the computational complexity when the number of antenna elements is increased.

Global Standardization Activities

• TeleManagement Forum Standardization Trends at Management World 2010

  

  Abstract
  This article reports the most recent standardization trends in the TeleManagement Forum (TM Forum), such as the Frameworx integrated business architecture and the user-led cloud study group Cloud Service Initiative (CSI) as well as the latest trends seen at Management World 2010 in May.

Practical Field Information about Telecommunication Technologies

• Troubleshooting User Systems in IP Services and Case Studies

  

  Abstract
  This article describes a method for troubleshooting user systems in Internet protocol (IP) services and presents case studies demonstrating its application. It is the third in a bimonthly series on the theme of practical field information about telecommunication technologies. This month’s contribution is from the Network Interface Engineering Group, Technical Assistance and Support Center, Maintenance and Service Operations Department, Network Business Headquarters.

Papers Published in Technical Journals and Conference Proceedings

• Papers Published in Technical Journals and Conference Proceedings