February 2025 Vol. 23 No. 2

Front-line Researchers

• Akira Fujiwara, Senior Distinguished Researcher, NTT Basic Research Laboratories

  

  Abstract
  In 2019, the definition of the ampere, the unit of electric current in the International System of Units (SI), was changed from the ampere with which it was physically impossible to implement the defined quantity of the unit of measure to the ampere that can be implemented using quantum devices. Researchers worldwide are now researching to establish a quantum current standard on the basis of the new definition of the ampere. We spoke with Akira Fujiwara, a senior distinguished researcher at NTT Basic Research Laboratories, who developed silicon single-electron transfer devices, one of the basic elements for implementing the electric current standard, and is working toward establishing the electric current standard using such devices through international collaboration. He explained his approach to establishing the electric current standard using silicon single-electron transfer devices, the community that is carrying out this approach, and his thoughts on conducting research in the global arena through friendly competition and discussion.

Rising Researchers

• Taiji Sakamoto, Distinguished Researcher, NTT Access Network Service Systems Laboratories

  

  Abstract
  The optical fibers that underpin current communications are single-mode optical fibers (SMFs), which have only one core (the path through which light travels). The transmission capacity limit of SMFs is reportedly 100 Tbit/s. Meanwhile, communication volume is expected to continue to increase, and current SMF-based communications may reach its limit between 2030 and 2040. In response to this, development of multi-core optical fibers (MCFs) is underway. We spoke with NTT Distinguished Researcher Taiji Sakamoto, who is researching and developing MCFs with up to 12 cores in a single optical fiber as well as optical amplifiers that limit the increased power consumption that results from an increase in the number of cores.

NTT IOWN Technology Report

• Release of NTT IOWN Technology Report 2024

  

  Abstract
  NTT Research and Development Planning Department released the NTT IOWN Technology Report 2024, which summarizes its vision for the Innovative Optical and Wireless Network (IOWN), the concept of which was unveiled in 2019, and technologies intended to make the world a better place for everyone. This article provides an Abstract of this report.

Regular Articles

• Field Verification of Automated Driving Using Cooperative Infrastructure Platform

  

  Abstract
  This article introduces a field verification of automated driving using the Cooperative Infrastructure Platform being developed by NTT laboratories. The Cooperative Infrastructure Platform aims to ensure stable communication in remote monitoring and improve the safety of automated driving. This platform is also being used as the communication function of the remote control system for automated driving developed by NTT DOCOMO, and field tests are being conducted in collaboration with NTT DOCOMO.

Global Standardization Activities

• Report on ITU-T SG13 Meeting Discussing Future Networks and Emerging Network Technologies

  

  Abstract
  The meeting of the International Telecommunication Union - Telecommunication Standardization Sector (ITU-T) Study Group (SG) 13, discussing future networks and emerging network technologies, was held in Geneva, Switzerland in July 2024. The partner organizations and NTT proposed a new work item for developing a new Recommendation “Framework of low-latency and energy-efficient communications in integrated networking” as a high-level architecture for IOWN (the Innovative Optical and Wireless Network), and the proposal was approved. This article provides an Abstract of the ITU-T SG13 meeting and explains our proposal of the new work item.

Practical Field Information about Telecommunication Technologies

• Case Study of Voice Interruption Involving Cordless Telephones Caused by Reflected Waves Due to Installation Environment

  

  Abstract
  This article presents a case study in which voice calls on cordless telephones of a business-phone system used in an environment, such as a factory where reflected waves occur, were interrupted. This is the eighty-sixth article in a series on telecommunication technologies.

Information

• Event Report: NTT Communication Science Laboratories Open House 2024

  

  Abstract
  NTT Communication Science Laboratories hosted the Open House 2024 from June 24 to 26, 2024, as an event showcasing its recent research achievements. While the COVID-19 pandemic restricted the scale of Open House events until 2023, the Open House 2024 had a larger capacity than the previous year with its venue floor space practically doubled and its period extended from two to three days. This article reports on the holding of the Open House 2024.

External Awards

• External Awards