Index
Vol. 79, No. 6, November 2024
Special Reports
5G Mobile Infrastructure Solutions Supporting Creation of Cohesive Society
NAKAO Akihiro
DOI Toshinori / TANGO Toshihiro
With the widespread dissemination of mobile communications networks that have become an indispensable part of daily life, fifth-generation mobile communication system (5G) networks realizing ultrahigh-speed, large-capacity data transmission are a focus of expectations as one of a social infrastructure system not only achieving further efficiency and automation, but also providing high added value from data obtained by Internet of Things (IoT) devices in order to promote economic growth and to solve social issues in a broad range of fields. As the extension of 5G network service areas depends on the business environments of individual mobile network operators, users are not always possible to use such services in certain areas.
In response to this situation, Toshiba Infrastructure Systems & Solutions Corporation has developed and released shared distributed antenna systems (DAS) that cover all sub-6 bands (frequency ranges used to provide 5G wireless services) allocated to 5G networks in Japan so as to realize infrastructure sharing systems that allow every Japanese mobile network operator to share the same equipment such as antennas, connected devices, and so on. These shared DAS feature a synchronous control function that allows multiple equipment to synchronize the timing of signals delivered from each antenna in order to achieve carrier aggregation using up to four bands for 5G networks, thereby making it possible to simultaneously provide high-speed communication environments with all mobile network operators. The shared DAS will play a critical role as a communication infrastructure underpinning cohesive society.
SUGIMOTO Masahiko / MASAKI Katsumi / IIDA Yasutaka
Infrastructure sharing systems for fifth-generation mobile communication system (5G) networks, in which multiple mobile network operators share the same distributed antenna system (DAS) equipment, are necessary to comply with new requirements to detect time division duplex (TDD) timing by each operator. In line with this, demand is growing to reduce the size of the TDD timing detection circuit to simplify DAS equipment configuration.
Toshiba Infrastructure Systems & Solutions Corporation has developed technology to detect TDD timing by demodulating synchronization signal blocks in 5G radio signals without the need for complicated processes resulting in increased computational amounts, such as clock recovery, channel estimation, and waveform equalization circuits, through improvements of both symbol synchronization accuracy in demodulation and phase rotation tolerance in data detection. We have succeeded in suppressing the size of the TDD timing detection circuit by implementing this technology together with our proprietary architectures such as shortening the processing delay time and processing circuit time multiplexing.
MASAKI Katsumi / SUGIMOTO Masahiko / OKUNI Hidenori
As a key element in infrastructure sharing systems, a shared distributed antenna system (DAS) is expected to support a next-generation open radio access network (Open RAN) system promoted by the O-RAN ALLIANCE, which will contribute to smaller installation space at sites and lower initial introduction and operating costs.
To flexibly accommodate technological changes from the RAN systems of individual mobile network operators to the Open RAN system, Toshiba Infrastructure Systems & Solutions Corporation is developing the following technologies for a shared DAS integrating a conventional base station radio frequency (RF) interface and O-RAN fronthaul (FH) interface functions: (1) a compact wireless signal processing circuit, (2) timing synchronization technology between different interfaces, (3) remote monitoring functions compliant with open specifications, and (4) resource management technology to prevent misconfigurations among mobile network operators. We have obtained positive results with these technologies and will continue efforts to further improve them.
OHYA Yasuo / TANDAI Tomoya / FUKUSHIMA Tatsuya / OHNO Kenichi
In recent years, local 5G, which allows municipalities and companies to build and operate their own fifth-generation mobile communication system (5G) networks according to regional and individual needs, has attracted attention as a means of constructing cyber-physical systems in various industrial spheres thanks to features such as high speed, high capacity, and low latency.
Toshiba Infrastructure Systems & Solutions Corporation has developed a distributed antenna system (DAS) for local 5G networks to provide stable wireless communications to social infrastructure systems linearly located along roads, railroads, rivers, and so on. DAS demonstration experiments have verified that it can expand the communication area while securing sufficient received power and stable communication speed inside a targeted area, as well as ensuring stable communication performance even in cases where shielding objects are located.
Adnan AIJAZ / ONIZUKA Kohei / YONEZAWA Yuki / TANIGUCHI Kentaro
A local 5G system, which allows municipalities and companies to build and operate their own fifth-generation mobile communication system (5G) networks according to regional and individual needs independent of mobile network operators, is expected to be used in various environments such as manufacturing sites and offices. However, as customization of local 5G systems is necessary to meet the different communication requirements of individual applications, introduction delays and maintenance difficulties have become serious issues.
Toshiba Corporation has established a local 5G system whose configuration can be changed flexibly and is compliant with an open radio access network (Open RAN) architecture formulated by the O-RAN alliance. We have developed a method to automatically generate and manage the end-to-end network slices, confirming stable operation through demonstration tests using the multivendor base station.
Feature Articles
HISAKUNI Yosuke / WATABE Kazuo / KUGIMIYA Tetsuya
Digital twins are attracting attention as way to analyze various data collected in physical space using a precise model that replicates an object in cyberspace. The analysis results are then used to make improvements to the physical object. Lately, demand has grown for applying digital twin technologies to facilitate efficient, precise bridge maintenance and management, including high-level diagnostics of structural soundness and deterioration, and precision assessment of conditions in the event of a disaster.
Toshiba Corporation is developing digital twin technologies to precisely replicate the behavior of bridges by using our large-scale structural analysis technologies acquired in the course of developing electronic devices. We have created a geometric model of an actual bridge, with simulation tests confirming that deformations of the entire bridge according to vehicle weight and temperature fluctuations closely match actual measured data.
TSUZUKI Yoshiyuki / TAKAHASHI Keita / IKUZAWA Takuya
With the prevalence of various systems utilizing artificial intelligence (AI), quality assurance initiatives for such systems have become increasingly important in recent years. To reduce the risks posed by AI, countries around the world, including Japan, have accelerated efforts to develop and update the relevant regulations and guidelines.
The Toshiba Group participates in developing guidelines for AI systems as a member of the domestic industry-academia working group while also formulating an original quality assurance system based on the guidelines for AI systems, and has developed an AI quality card to summarize and visualize quality information. Part of these efforts entails developing an AI quality card generation system operating on a machine learning operations (MLOps) platform, which can automatically generate AI quality cards by aggregating and visualizing quality information according to the template. Sharing up-to-date quality information with customers by means of AI quality cards from the planning to the operation and quality assurance phases is expected to contribute to the realization of trustworthy AI systems.
AIZAWA Toshimitsu / SHIBAYAMA Takeshi / WATANABE Hiroki
The electrification of automobiles is being actively promoted in countries across the world as part of carbon neutrality initiatives, reflecting increasing awareness of global climate change.
The Toshiba Group has developed the SmartMCD™ series gate driver integrated circuit (IC) with a built-in microcontroller for motor control drivers (MCDs) to achieve a balance between reduced cost and improved performance of in-vehicle systems, and Toshiba Electronic Devices & Storage Corporation has started deliveries of the TB9M003FG. It incorporates the following three features: (1) high-speed motor control of 20 000 times per second via a vector engine (VE) capable of reducing the central processing unit (CPU) load despite using a low-cost CPU, (2) single-shunt current detection using triangular, sawtooth, and inverse sawtooth wave carriers capable of improving the conventional current detection rate from 0% by up to 100% at low duty times, and (3) software-defined functionality capable of supporting multiple controls by changing the embedded software.
KAWAI Shusuke / MIYAZAKI Koutaro / UENO Takeshi
Next-generation power semiconductors capable of performing high-speed switching thanks to performance improvements are driving demand for power converters which offer miniaturization capabilities and high efficiency. However, noise generated by high-speed switching operations poses a serious obstacle to developing sufficiently efficient and reliable power converters.
To rectify this situation, Toshiba Corporation has developed a digital active gate driving (AGD) circuit that can perform low-loss, high-speed operations by controlling power semiconductors in accordance with changing conditions. Furthermore, we have developed a smart gate driver integrated circuit (IC) combining the digital AGD circuit with a digital overcurrent protection circuit capable of automatically adjusting its parameters in a single package. Experiments on a prototype chip have verified that switching loss is reduced by 27% and shutdown time is 2.35 μs when overcurrent is applied.
SUGANUMA Naotaka / UEDA Takashi / BABA Takayuki
More offshore wind farms than ever before are being built as a major renewable energy source with the goal of achieving carbon neutrality by 2050. For mass introduction of offshore wind farms to succeed, labor-saving technologies are essential to reducing operation and maintenance (O&M) costs, which account for more than 30% of the total operating costs.
To rectify this, Toshiba Energy Systems & Solutions Corporation has developed the following labor-saving inspection technologies for offshore wind farms: (1) technology to automatically inspect the exterior of wind turbines using drones equipped with a camera, and (2) technology to remotely inspect the interior of wind turbine nacelles using remote access devices. We have confirmed the effectiveness of the former technology through demonstration experiments using onshore wind turbines as well as the basic functionality of the latter technology.
KANAWA Takuya / KONDO Yuji
Many companies delivering a broad range of services have found it necessary to implement cross-site data analyses as well as precautionary measures in preparation for emergencies via data, which are collected from Internet of Things (IoT) devices at individual sites and replicated across other sites.
Toshiba Digital Solutions Corporation supplies GridDB, a scale-out database for appropriate management of various data from IoT devices. We have developed and released a site-to-site database replication function that provides excellent processing performance and ensures data consistency between different sites by expanding the existing intra-site replication function of GridDB, thereby enabling disaster recovery operations and cross-site data analyses using replicas of IoT data.
KAMIYA Tomoki / TATEYAMA Chihiro / NAKAMURA Yusuke
Power equipment failure can occur due to partial discharge caused by an electric field concentrated in defects of solid insulation materials used in equipment. Failure prediction technologies that use sensors to detect partial discharge are crucial for safe, stable equipment operation, however, detecting a weak partial discharge signal amidst noise in very noisy conditions is very difficult.
Toshiba Infrastructure Systems & Solutions Corporation has developed a method to identify a partial discharge signal from noise even in severely noisy environments by applying clustering techniques to classify pulse waveforms in sensor signals while taking into consideration phase broadening. This method caters to the demand for applying optimal diagnostic services according to power equipment characteristics and installation environments.
Frontiers of Research & Development
Highly Sensitive Odor Sensing Technology to Detect Specific Odors Using Quartz Crystal Resonator Coated with Nanospace-Controlled Metal-Organic Framework (MOF) Thin Films
*Company, product, and service names appearing in each paper include those that are trademarks or registered trademarks of their respective companies.