Overview The NTT Group has taken up the challenge of self-transformation toward growth in profits as declared in its Medium-Term Management Strategy °»Towards the Next Stage 2.0.°… There are high expectations of the NTT Group for technological development and social contributions in fields of great global interest such as artificial intelligence, Internet of Things, and cybersecurity. At the dawn of a new year, we asked Senior Executive Vice President Hiromichi Shinohara to tell us about NTT Group plans for 2016 and specific initiatives for creating new value.
Overview Shinji Matsuo, Senior Distinguished Researcher at NTT Device Technology Laboratories, continues his challenging work on achieving optoelectronic integrated circuits on silicon substrates and making them into economical and low-power devices°Ĺkey issues in the worldwide information technology industry. He leads a group dealing with a unique form of research, so we asked him to give us some background on the inception of this groundbreaking technology. We also asked him to describe remaining issues and to comment on his role as a researcher.
Feature Articles: Photonics-electronics Convergence Hardware Technology for Maximizing Network Performance
Abstract Network traffic will continue to increase exponentially as we get closer to deploying fifth generation mobile networks, and as the Internet of Things and big data services expand through 2020 and beyond. In these Feature Articles, we look at trends in the research and development of advanced hardware technology designed to achieve substantial increases in the capacity of communication networks with much lower capital and operating expenditures in the next 5 to 10 years. We focus in particular on technology based on new concepts and principles that involve the convergence of photonics and electronics.
Abstract To increase the transmission capacity of optical fiber transmission systems, we have developed a multiplexer-digital-to-analogue converter and an optical time-division multiplexing modulator, which respectively generate high-speed signals in the electronic and optical domains. With these devices, we can significantly increase the capacity per wavelength channel.
Abstract Drastic improvement of the signal-to-noise ratio (SNR) of optical communication systems is necessary in order to make rapid progress in digital-coherent optical communication technology based on multilevel modulated signals. In this article, we describe the recent progress made in phase sensitive amplifiers (PSAs) based on PPLN (periodically-poled lithium niobate) waveguides. These PSAs are capable of low-noise amplification and both phase and amplitude regeneration, which improves the SNR in optical transport systems.
Abstract NTT has developed lateral current-injection membrane lasers fabricated on silicon for short-reach optical interconnections. The lasers are fabricated using the crystal growth technique on a bonded substrate consisting of compound semiconductors and silicon. Integration of the lasers and silica-based waveguides has also been achieved recently. In this article, we introduce directly modulated lateral-current injection membrane lasers and their integration with silica-based waveguides.
Abstract We developed a design technique for an electronic and photonic integrated circuit that involves using an equivalent circuit of optical devices in an electrical circuit simulator. Key features are the use of structural and physical parameters as calculation parameters in the equivalent circuit to provide a practical device design and the use of an intermediate frequency to model the wavelength dependence of optical devices in an electrical circuit simulator. By combining these techniques, we simulated the bit error rates and eye diagrams of a device that integrates an optical and electrical circuit. This technique turns an electrical circuit simulator into a photonics-electronics convergence simulator.
Abstract Today°«s large-scale datacenters have been constructed using a large number of electrical routers and switches, and they are consequently facing problems such as high power consumption, high latency, and low network throughput. Some of the research aimed at solving these problems focuses on photonic datacenters based on optical technologies. In this article, we introduce the underlying optical packet switching technologies of a hybrid optoelectronic router that researchers at NTT Device Technology Laboratories are currently working on. We also explain a high-speed optical switch, which is a key component of the router.
Abstract Network virtualization technology is a topic of great interest because of its ability to emulate network features in software. In this article, we present a technique for adding programmable hardware acceleration to network virtualization equipment, which is then used in coordination with software to preserve the software°«s flexibility while raising the limits on its performance.
Abstract It is essential that we recognize both our own physical movements and mental condition if we are to achieve and improve goal-directed actions in sports. However, it is not easy to adequately understand one°«s own body-mind state during complicated sports actions. A potentially better way to overcome this problem is to use auditory feedback because auditory perception has higher temporal resolution than visual perception, and it interferes very little with the performance of an action. In this article, we propose real-time auditory feedback techniques designed to sonify the temporal coordination of the body and the excessive activation caused by mental pressure when participating in sports based on surface electromyography and acceleration signals. Our aim was to determine when and how the body-mind behaves. We believe that these techniques will help players learn the skill needed for a desired action and will reveal a player°«s physical and mental condition when playing sports.
Abstract When optical fiber is installed on customer premises, there may be a delay in activating it if the customer complains about the conspicuous appearance of the exposed wiring. We have developed an invisible optical fiber to improve the appearance of the installed cable and to reduce the amount of unsuccessful activation work.
Abstract The NetroSphere concept proposed by NTT laboratories aims to divide network functions into small modular components and to flexibly assemble those components. This makes it possible to quickly form proportional networks that can offer required functionality according to user needs. As a result, carrier networks will achieve enhanced flexibility and elasticity while also drastically reducing costs. This article introduces the architecture to provide network functions and resources via APIs (application programming interfaces) to collaboration partners such as service developers.
Abstract As an established thought leader in telecom operations related standards, the TeleManagement (TM) Forum is making good progress on three strategic programs in addition to its ongoing work in developing operation systems. This article provides an overview of recent TM Forum initiatives concerning service interaction between telecom operations and over-the-top content toward virtualization, the proof of concept Catalyst project, and overall TM Forum related developments.
External Awards/Papers Published in Technical Journals and Conference Proceedings