November 2021 Vol. 19 No. 11

View from the Top

• Hideaki Ozawa, Chief Operations Officer and Chief Technology Officer, NTT Research, Inc.

  

  Overview
  NTT Research focuses on cutting-edge basic research in the fields of quantum computing, cryptography, blockchain, and medical/health informatics with partners around the world. Two years after its establishment, it has won several prestigious awards, including the International Association for Cryptologic Research (IACR) Test-of-Time Award, SPIE Maiman Laser Award, and IACR Crypto 2020 Best Paper Award. The institute’s achievements also include solving the 20-year-old problem of program obfuscation. We interviewed Hideaki Ozawa, chief operations officer and chief technology officer of NTT Research, about the progress of research and the art of management.

Front-line Researchers

• Shiro Saito, Senior Distinguished Researcher, NTT Basic Research Laboratories

  

  Overview
  Quantum information technology is attracting attention as a source of technological innovation that will bring about major changes in the future economy and society. Countries around the world, including Japan, the United States, Europe, and China, are positioning research and development of quantum information technology as one of their national strategies. We interviewed Shiro Saito, a senior distinguished researcher at NTT Basic Research Laboratories and who is making a significant contribution to the development of quantum information technology, about the progress of his research and his attitude as a researcher.

Rising Researchers

• Ryo Ishii, Distinguished Researcher, NTT Human Informatics Laboratories

  

  Overview
  Digital Twin Computing is one of the three key fields of technology in the IOWN (Innovative Optical and Wireless Network) vision. In order to build a digital-world representation of a person that includes not only their external aspects, but also their internal aspects, such as consciousness and thought, it is essential to understand and model the mechanisms of human communication. In this article, we speak to Distinguished Researcher Ryo Ishii, who works with multimodal information including speech, language, and body movement with the aim of understanding the mechanisms of human communication, for example in how a person conveys their mental state.

Feature Articles: NTT DOCOMO’s Initiatives on 5G evolution & 6G

• Trends and Target Implementations for 5G evolution & 6G

  

  Abstract
  In Japan, commercial 5th-generation mobile communication systems (5G) services first became available in March 2020. Studies of the next generation of communication services (6G) and the telecommunication technology of the 2030s are now gathering momentum. This article provides a summary of the domestic and international trends and schedule prospects for 6G research and development, and the 5G evolution & 6G concept proposed in the DOCOMO 6G White Paper.

• Research of Transparent RIS Technology toward 5G evolution & 6G

  

  Abstract
  The introduction of the 5th-generation mobile communications system (5G) commercial services has begun throughout the world, and at present, research toward the further development of 5G (5G evolution) and the development of 6G as the next-generation mobile communications system is being actively pursued. In this article, we describe the intelligent radio environment (IRE), an important concept in “New Radio Network Topology” now under discussion on the road to 5G evolution & 6G. We also describe NTT DOCOMO’s initiatives toward the reconfigurable intelligent surface (RIS), an important component of IRE, and metamaterial/metasurface technologies as elemental technologies of RIS.

• Research on NTN Technology for 5G evolution & 6G

  

  Abstract
  In the 5th-generation mobile communication system (5G) evolution & 6G, extreme coverage extension is being studied for use cases in all places including air, sea, and space. Non-terrestrial networks using geostationary satellites, low earth orbit satellites, and high-altitude platform stations are promising tools for providing high-quality communication services in areas that cannot be covered by the conventional mobile communication network. In this article, we describe these technologies and the details of a 39-GHz band airborne propagation measurement experiment performed using a small airplane at an altitude of about 3 km.

• Improving Communication Performance in High-mobility Environments by Millimeter-wave Base Station Cooperation for 5G evolution

  

  Abstract
  Although the 5th-generation mobile communications system (5G) commercial services are now being provided, further evolution of 5G is needed to meet a variety of future demands. As part of these studies, we consider the provision of millimeter-wave high-speed communications over a wide area to multiple mobile stations traveling at high speed. In a high-mobility environment, area construction must be performed over a wide area through the cooperation of multiple base stations. Additionally, to achieve simultaneous communications with multiple mobile stations, interference must be suppressed so that signals transmitted to each mobile station do not interfere with each other. To deal with these issues, we developed millimeter-wave base station cooperation technology to enable multiple base stations to cooperate with each other while suppressing inter-mobile-station interference by applying digital beamforming to base stations to generate and control beams by digital signal processing. We showed through outdoor experimental trials that high communication speeds could be achieved over a wide area.

Regular Articles

• High-gain Optical Parametric Amplifier Module by Using a PPLN Waveguide and Its Application to Quadrature Squeezing

  

  Abstract
  Optical parametric amplification is expected as a key technique for high-speed optical fiber communication and optical quantum computing. We developed a high-gain and broadband optical parametric amplifier (OPA) module by using a periodically poled lithium niobate (PPLN) waveguide, the single-mode core of which is directly bonded to a lithium tantalate substrate. The OPA is assembled as a pump-combiner-integrated module with four optical-fiber input/output ports. By improving the fabrication processes of the PPLN waveguide and the assembly techniques of OPA modules, we achieved over-30-dB phase sensitive amplification with a continuous-wave pump. By using the PPLN waveguide, we successfully obtained over-6-dB squeezed light, the spectral bandwidth of which was 2.5 THz. This high-gain broadband OPA module will help build an advanced information society.

• Development of Beyond 100G Optical Cross Connect (B100G-OXC) System

  

  Abstract
  The rapid increase in Internet traffic is expected due to the spread of network services such as 5G (fifth-generation mobile communication), Internet of Things, and cloud. To economically expand the capacity in the core network of the NTT Group, NTT Network Innovation Center developed the Beyond 100G Optical Cross Connect (B100G-OXC) system, which enables beyond 100-Gbit/s per wavelength optical transmission. This article gives an overview of this system.

Global Standardization Activities

• Standardization Activities in the Asia-Pacific Region—New Management Structure Approved at the 33rd Asia-Pacific Telecommunity Standardization Program (ASTAP) Meeting

  

  Abstract
  The 33rd Asia-Pacific Telecommunity Standardization Program (ASTAP) meeting was held in June 2021 in an online format. ASTAP aims at strengthening standardization activities in the information and communication technology field in the Asia-Pacific Telecommunity and contributing to the establishment of international standards as a region. This article describes the main results of ASTAP-33 and the industry workshop held during the meeting.

Information

• Event Report: NTT Communication Science Laboratories Open House 2021

  

  Abstract
  NTT Communication Science Laboratories Open House 2021 was held online, the content of which was published on the Open House 2021 web page at noon on June 3rd, 2021. The videos of 5 talks and 29 exhibits presented our latest research efforts in information and human sciences and were played more than 6000 times within the first month after the event.

External Awards/Papers Published in Technical Journals and Conference Proceedings

• External Awards/Papers Published in Technical Journals and Conference Proceedings