October 2023 No.97
Video distribution traffic accounts for 65-70% of the downstream access network traffic, which has continued to grow in recent years. Advances in video image quality and video compression technologies, coupled with standardization efforts, have led to a significant increase in the maximum required bandwidth per broadcasting channel. Specifically, over the last two decades, the maximum content bitrate has multiplied by approximately 40 times (pre-compression), and 20 times (post-compression) for IPTV, while domestic radio frequency broadcasting has shown the pace of 5 times. At the same time, the future growth of the market is anticipated to be driven not only by the transition to 8K video but also by the integration of Extended Reality (XR) video services that combine 360° 3D video, AI, and digital twin technologies. Taking this opportunity, this paper reviews the trends in video communication technology and the initiatives of Sumitomo Electric Industries, Ltd. The paper also discusses various key indexes required for all-optical and wireless networks connecting cloud computing to homes and workplaces, with a particular focus on what is called the Motion-to-Photon latency, which is essential for realizing immersive and interactive 3D and XR video distribution services, and considers its impact on other key indexes.
Intelligent communication technology is an indispensable part of the infrastructure that supports modern society. In particular, wireless communication systems using high-frequency radio wave carriers have made remarkable progress in the last 30 years. In 2020, 5th-generation services started to realize high-data-rate transmission and low signal latency. The environments in which wireless communication networks operate have expanded to include the open sea and low earth orbit. To date, we have developed many kinds of commercial transmission devices for optical wired and wireless communications. We were the first company in the world to successfully mass produce and commercially ship Gallium Nitride high electron mobility transistors (GaN HEMTs), a key device for cell phone base stations, and have the top market share. This paper describes compound semiconductor devices represented by GaN HEMTs as well as novel crystal and device technology for discontinuous performance enhancement.
Climate change poses a global challenge that necessitates the reduction of carbon dioxide (CO2) emissions. To reduce CO2 emissions from motor vehicles, which are major emission sources, it is important not only to improve vehicle exhaust performance, but also to improve infrastructure such as traffic signal control at intersections to mitigate traffic congestion and energy consumption. A quantitative evaluation of the effects resulting from traffic signal control improvements is essential for their dissemination. Currently, however, there is no well-established method to calculate CO2 emissions of vehicles traveling through intersections. We have developed a CO2 emissions calculation model intended for widespread adoption. This model facilitates the quantitative evaluation of CO2 emissions reduction resulting from traffic signal control improvements.
The global need for pedestrian detectors is increasing to improve traffic safety and efficiency. In order to achieve accurate detection at intersections, the detectors need to be placed in the right locations. However, constructing new poles requires much effort and cost, making it essential to utilize existing poles for widespread deployment of the detectors. Meanwhile, achieving effective pedestrian detection on both far and near sides presents challenges due to the limited sensor viewing angles. Additionally, many sensors are unable to detect pedestrians directly beneath them, thereby restricting the possible installation locations. To overcome these challenges, we have developed a cost-effective radar system with a wide vertical coverage angle, offering improved installation flexibility. This paper introduces the innovative radar and presents experimental results demonstrating its expanded detection area.
In recent years, the convergence of several services and information technologies has revolutionized our daily lives. However, failures in communication infrastructure can have profound consequences, necessitating increased reliability and availability of communication equipment. This paper focuses on our research and development efforts in high-speed Ethernet equipment, specifically addressing MC-LAG (multi-chassis link aggregation) and precision time synchronization in supporting high-quality 5G wireless systems.
To address the rapid increase in data traffic, data centers have increased the number of channels. However, current systems use one semiconductor laser per channel, resulting in higher power consumption and costs due to the increased number of components. To overcome these challenges, a new approach has been proposed, where light from a single laser with high output power is branched to create multiple channels. However, existing telecommunication lasers have reached the limit in achieving high output power with single-mode lasing. Therefore, we have conducted research on 1.3-μm-wavelength InP-based photonic-crystal surface-emitting lasers (PCSELs) as a next-generation semiconductor laser that can achieve both single-mode lasing and high output power. We have demonstrated single-mode operation with a high output power of over 200 mW under continuous-wave conditions at room temperature by using dry-etching and regrowth techniques. In addition, we have achieved a high output power of 4.6 W in short-pulsed operation. These results suggest that PCSELs can be used not only for communications but also for sensing applications.
Sumitomo Electric Industries, Ltd. developed polytetrafluoroethylene (PTFE) porous membranes ahead of the world. In the early 2000s, utilizing the membranes, the Company develop hollow fiber membrane water modules with excellent chemical resistance and strengths. The modules have been widely applied to water purification, sewage treatment, and industrial wastewater treatment around the world. With the increasing demands for the recovery of salt components, we focused on the application of these modules to membrane distillation for the separation of trace components such as salt in seawater and rare-earth elements in water resources, taking advantage of the excellent hydrophobicity of PTFE. This paper reports on the development of a PTFE hollow fiber membrane with superior water pressure resistance and gas permeability, both of which are critical for membrane distillation.
Nissin Ion Equipment Co., Ltd. conducted research on electron transport properties of an argon-ion-implanted amorphous InGaZnO (a-IGZO) film deposited on a glass substrate. The research obtained valuable data on electron concentration and Hall mobility of the film at various depths from the surface. The result shows that the a-IGZO film has a high electron concentration in deep regions compared with an argon plasma-treated a-IGZO film. In addition, the company estimated the argon stopping powers of a-IGZO and the donor level of 0.05-0.1 eV below conduction band bottom energy, which can be applied to resistance control for a-IGZO device processing.
Sumitomo Electric Industries, Ltd. conducted a demonstration of its 2 MW/8 MWh redox flow (RF) battery system for multiple-use applications (MUA) in California, U.S.A. The system was operated within the distribution network to achieve peak shaving and voltage regulation. In the California Independent System Operator market, it simultaneously participated in the energy and ancillary service markets. In addition, the system successfully demonstrated microgrid operations for both black start and seamless transitions, providing MUA for normal and emergency operation to existing residential customers.
As wind turbines grow in size and output capacity, submarine cables transmitting the generated electric power face challenges related to manufacturability, cost, and workability. To overcome these challenges, we have been developing submarine cables without the impervious structure. However, it is difficult to estimate cable life due to the progression of water tree deterioration in flooded cable insulation. To evaluate the cable life of non-impermeable structure, we examined a long-term water tree test method capable of simulating 30 years of operation. By analyzing the time variation of supersaturated moisture content in cable insulation, realistic test periods can be achieved. Future endeavors involve the development of water-tree-resistant cables to withstand long-term operation and high pressures on actual lines, utilizing the test method.
Compound semiconductors have beneficial features that enable high performance devices. In this study, we utilized synchrotron radiation x-ray photoelectron spectroscopy (XPS) techniques to precisely analyze semiconductor surface and interface states, which significantly affect device performance. Regarding gallium nitride high electron mobility transistor (GaN-HEMT) devices for wireless communication, x-ray energy was lowered to 600 eV to study the effect of the O2 ashing process, achieving a probing depth of approximately 2 nm. Combined with photoluminescence analysis, it was confirmed that inappropriate process conditions increased the escape of nitrogen atoms, surface oxidation, and defects in GaN crystals. For the InP-based photodiodes used as detectors in optical communication, the surface potential of InP covered with dielectric films was evaluated, using hard x-ray photoemission spectroscopy with an excitation energy of 7940 eV. Based on our analysis, the film deposition condition was optimized and the leakage current at the interface was successfully reduced to obtain sufficiently high optical sensitivity. This study has demonstrated that timely utilization of synchrotron radiation analysis is extremely effective in shortening the product development of Sumitomo Electric Industries, Ltd.
In recent years, the shift to electric vehicles and the electrification of automotive components are progressing toward the realization of a decarbonized society.The electrification of components has expanded the use of by-wire control, which uses electrical signals to control the target. However, by-wire control has a shortcoming in that it cannot control components if the vehicle power source, such as a lead-acid battery, fails. Sumitomo Wiring Systems, Ltd. and AutoNetworks Technologies, Ltd., both of which are Sumitomo Electric Group companies, have jointly developed an integrated backup battery that enables uninterrupted by-wire control of multiple components even in the event of a vehicle power failure .
In recent years, the advancement of cloud computing, video distribution, and AI has led to a rapid increase in telecommunications traffic and the construction of largescale data centers (DCs). Since optical cables that connect DCs are usually installed in outdoor ducts, the technology for densely installing these cables in a limited duct space is indispensable. In 2017, Sumitomo Electric Industries, Ltd. developed and commercialized an optical cable with the world’s highest fiber count of 6,912. The Company also developed wiring solutions and has contributed to increasing cabling density and improving workability throughout DCs. The Company has recently developed and started sales of a 3,168-fiber-count optical cable with 200 μm fibers and a 2,016-fiber-count optical cable with 250 μm fibers as ultra-high-fiber-count and high-density optical cables suitable for installation in ducts used in Japan and other areas. This paper describes the structure and features of these new cables.
In recent years, semiconductor devices for marine and meteorological applications have become more powerful, and solid-state radars are replacing conventional magnetron radars. Long service life is one of the advantages of solidstate devices. Although magnetrons need to be replaced periodically, semiconductors do not require replacement and thus help reduce radar maintenance costs. It is difficult to observe small objects with magnetron radars due to large frequency fluctuations. In contrast, due to their high-frequency stability, solid-state radars improve observation performance by enabling observation of objects that were difficult to observe in the past. On the other hand, to provide solid-state radars with a detection range equivalent to that of magnetron radars, a plurality of semiconductor devices must be arranged in a row, and their output power needs to be further increased to reduce the required number of devices. We have developed an S-band GaN HEMT with the highest output power of 800 W in the industry. This report describes the features of this new device.
With the rapid growth of renewable energy and electric vehicles (EVs) to realize carbon neutrality, demand for next-generation power semiconductors is expanding. In particular, silicon carbide (SiC) is beginning to be used in some application areas as a new material that achieves higher voltage resistance and less power consumption than silicon. However, the high manufacturing cost is a problem that needs to be solved before it is widely used. In the manufacturing process of SiC wafers and devices, grinding is used to finish wafer surfaces with high efficiency. However, grinding SiC, a hard-brittle material, poses the problems of (1) a high tool consumption rate and (2) high grinding resistance. To solve these problems, the development of a high wear-resistance tool capable of grinding SiC with low cutting resistance has been desired. Against this background, A.L.M.T. Corp. has developed a vitrified bond wheel that achieves both a long tool life and a low grinding resistance at the same time with its proprietary technology for the high-precision dispersion control of submicron structures. A.L.M.T. Corp. began marketing the new grinding tool “Nanomate Masspower” in fiscal year 2022.
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