what is LiFi?

In an environment where a local 5G wireless base station is installed on the roof of a research building at our university, we evaluated the transmission characteristics of 4x4 MIMO transmission for synchronous TDD and downlink data channels in comparison with SISO transmission. As a result, regarding the received power characteristics, the difference between the simulation value based on the ray tracing method and the actual measurement value at 32 points in the area was within a maximum difference of about 10 dB, and good agreement was obtained. As for the transmission throughput characteristics, the cumulative distribution of the transmission throughput values shows that the simulation value for SISO transmission is about 115 Mbps, and the actual measurement value is 105 Mbps, with a difference of about 10 Mbps at a cumulative value of 50%. On the other hand, in MIMO transmission, the simulation value is 380 Mbps, and the actual measurement value is about 420 Mbps, which is a difference of about 40 Mbps.In addition, the improvement effect of MIMO transmission throughput is about 3.3 times the simulation value and about 4.0 times the actual measurement value. A sufficient transmission throughput improvement effect in MIMO transmission was clarified.

Millimeter-wave technologies are growing for sensing and communication applications in recent years. The service of the 5G mobile communication systems has already begun and currently the service area is extending from hot spots gradually. The development of the RF technologies of mobile communication systems shifts higher frequency band such as Teraherz-wave band for Beyond 5G systems toward 2030 as a next stage.

High-gain antennas for high S/N ratio and high angular resolution can be designed in the millimeter-wave and Teraherz-wave bands even though the physical size of the antenna is small. Beam-scanning function is attractive to detect the target in sensing systems and to cover wide area with high gain in communication systems. Technologies of planar array antennas and multiple beam antennas are required for these applications.

This talk presents the distinct features of the planar antennas, multiple beam antennas and lens antennas. The designs and the principles of the various antennas are explained. The key technologies of the planar array antennas and the lens antennas for beam-scanning in the millimeter-wave and Teraherz-wave bands are presented in this talk. Transmission line transitions to connect RF-IC and waveguide feeding horn antennas for primary radiators of lens antennas are also mentioned in this talk.

Cellular and Wi-Fi, the two main types of mobile communication, both use a server-client form of communication in which terminals connect to a base station and communicate with each other. In contrast, there is a form of communication in which terminals connect directly to each other. This is known as peer-to-peer communication. The form of communication known as wireless mesh is a type of peer-to-peer communication in which terminals relay messages to each other in a bucket relay fashion so that terminals in remote locations can communicate with each other without having to go through a base station.

　PicoCELA is a company with its own wireless mesh technology and develops and sells Wi-Fi access points that use this technology for backhaul. Backhaul refers to the relay links that connect base stations to the Internet. The coverage area of each base station is getting smaller every year, requiring LAN cabling for more base stations, i.e. more backhaul. In anticipation of the proliferation of such small cells, the focus has turned to wireless mesh to reduce the need for cumbersome wired LAN cabling for backhaul, and Wi-Fi access points equipped with PicoCELA wireless mesh technology are being deployed at more than 1000 sites, mainly in Japan.

Developed as a backhaul for small cells, PicoCELA's wireless mesh technology solves the challenges specific to small cell deployments and provides extremely stable wireless mesh communications that can successfully withstand use in harsh enterprise environments. This high stability of wireless mesh technology can be applied in many other areas. This presentation describes PicoCELA's wireless mesh technology, followed by some use cases and finally future application developments.

In this presentation, we will talk about our trial in the nationally funded R&D "5G-advanced project", which we have been working on for four years from 2019 to 2022 to build a mmWave (FR2) communication system based on an SDR technology that Kozo Keikaku Engineering has cultivated over many years. The goal of this project was to provide highly reliable services in the mmWave band that meet various combinations of communication quality requirements, for example, low latency and mMTC, eMBB and URLLC, and so on. To achieve these requirements, the University of Electro-Communications (UEC) proposed a grant-free non-orthogonal multiple access (PHLEX1) that meets the demand for low latency and multiple connections, and a coordinated multi-point for mmWave beamforming (PHLEX2) which avoids communication interruptions due to blockage. We have developed (1) advanced mmWave hybrid beamforming technology and (2) multi-RU coordinated control technology, which are the keys to realize mmWave communication systems, and (3) advanced software-based wireless physical access represented by 5G NR. As for (1), we established a hybrid beamforming technology by combining analog control and digital control using a 32-element array antenna, and constructed an RU (4 related patents registered). In (2), we established a technology to integrate and control multiple RUs with the above (1) necessary for PHLEX2 from a single DU. In addition, (3) has acquired the technology by expanding the 5G specification based on the 5G RAN open source (OAI: OpenAirInterface) and realizing PHLEX1/PHLEX2 on our mmWave system. These established technologies are one of the few demonstration base cases using actual equipments for the Beyond 5G era.

IoT-related products and services used at various segments are now requested to be used for developing smaller, more complex, and more sophisticated products in a shorter development period, and not only Western countries but also China and other Asian countries are following this trend. Companies providing these IoT related products and services are getting stronger not only at consumer segment but also other segments such as industrial equipment.

In particular, IoT devices tend to emphasize the hardware aspect, but these are not just those that incorporate firmware that realizes only basic movements with conventional ICs and components. They highly integrate more functions in fewer components to develop smaller and lower cost products. Depending on the product or service, they utilize the right communication protocol in the right place for the right person, and incorporate edge/computing incorporating AI and ML (Machine Learning) to save power and reduce communication costs. In addition, there is a need to develop products that flexibly utilize various technologies, such as the integration of global standards, and in order to provide these products and services in a timely manner, it is getting indispensable to shorten the development period in order to be competitive in the global market.

In other words, not only the development of hardware as a platform, but also the quality and development speed of firmware/software that give higher value to the hardware are getting more important than ever imagined.

At Nordic session, we will introduce Nordic's nRF Connect SDK, various accompanying software and development support tools that support your challenges for developing firmware and software targeting IoT market.

　

To realize Beyond5G/6G, various services and applications that make use of 5G wireless technology have been provided, and further development is planned.

In this presentation, we will introduce test methods for "O-RAN" and "NTN".

　

　

In fiscal year 2022, new regulations were implemented under the Civil Aeronautics Law in Japan allowing for Level 4 unmanned drone flights over manned areas for various purposes including logistics. This lifting of the ban on Level 4 flights is expected to advance the use of drones in Japan. The lecture will introduce case studies in different fields such as logistics, inspection, civil engineering, construction, and security to explain the potential of drones in the future.