Since 5G began its rollout in 2018 or 2019, fifth-generation wireless networks have spread across the globe to cover hundreds of millions of users. But while it offers lower latency than precursor networks, 5G also requires more base stations. To avoid installing unsightly equipment on more and more shared spaces, Japanese companies are developing transparent glass antennas that allow windows to serve as base stations that can be shared by several carriers.

Because 5G networks include spectrum comprising higher frequencies than 4G, base stations for 5G networks serve a smaller coverage footprint. Which means more base stations are needed compared to 4G. Due to a lack of installation spots and the high cost of rolling out 5G networks, carriers in Japan have been sharing mobile infrastructure.

Last month the Tokyo-based communications company JTower announced the deployment of the new glass antenna, created in part by glassmaker AGC (one of the world’s largest) and the mobile carrier NTT Docomo. The first was installed on a window in Tokyo’s Shinjuku district.

The product is “the world’s first antenna that turns a window into a base station that can be attached to a building window inside and turn the outdoors into a service area without spoiling the cityscape or the exterior appearance of the building,” says Shota Ochiai, a marketing manager at AGC.

NTT Docomo reports that it uses transparent conductive materials as the basis for its antenna, sandwiching the conductive material along with a transparent resin, the kind used in laminated windshields, in between two sheets of glass.

“I don’t think the idea for using transparent conductive materials as an antenna existed before,” said AGC’s Kentaro Oka in a company statement. “The durability of the antenna was significantly increased by placing the conductive materials between glass.”

The transparent antenna can be engineered according to the thickness of the glass to reduce the attenuation and reflection of the radio signals being absorbed and emitted by the window-sized device. “The glass antenna uses our proprietary technology to smooth out the disruption in the direction of radio waves when they pass through a window,” says Ochia.

A brief history of the window antenna

Branded WAVEANTENNA, the antenna is installed on the interior surface of windows. Apart perhaps from its cabling, the WAVEANTENNA is an otherwise inconspicuous piece of equipment that is often tucked out of sight, placed near the top or otherwise at the edges of a window.

It is compatible with frequencies in the 5G Sub6 band—meaning signals that are less than 6 gigahertz (GHz). Sub6 antennas represent critical portions of a 5G deployment, as their lower frequency ranges penetrate barriers like walls and buildings better than the substantially higher-bandwidth millimeter-wave portions of the 5G spectrum.

An earlier version of the product was launched in 2020, while a version that could handle sharing by multiple cell networks was introduced last year, according to AGC. The company says its antenna is optimized for frequencies between 3.7 and 4.5 GHz bands, which still allows for substantial bandwidth—albeit not comparable with what an ideal millimeter-wave 5G deployment could reach. (Millimeter waves can deliver typically between 10 and 50 GHz of bandwidth.)

The glass antenna can help expand 5G coverage as infrastructure sharing will become more important to carriers, AGC says. Besides increasing the number of locations for base stations, the device makes it easier to select the appropriate installation height, according to Ochiai.

AGC has also applied 5G glass antennas to automobiles, where they can help reduce dropped signals. The company reports that users include Halo.Car, an on-demand EV rental service in Las Vegas that relies on high-speed networks for remote drivers to deliver cars to customers.

Telecom engineers and researchers face several challenges when it comes to testing their 5G and 6G prototypes. One is finding a testbed where they can run experiments with their new hardware and software.

The experimentation platforms, which resemble real-world conditions, can be pricey. Some have a time limit. Others may be used only by specific companies or for testing certain technologies.

The new IEEE 5G/6G Innovation Testbed has eliminated many of those barriers. Built by IEEE, the platform is for those who want to try out their 5G enhancements, run trials of future 6G functions, or test updates for converged networks. Users may test and retest as many times as they want at no additional cost.

Telecom operators can use the new virtual testbed, as can application developers, researchers, educators, and vendors from any industry.

“The IEEE 5G/6G Innovation Testbed creates an environment where industry can break new ground and work together to develop the next generation of technology innovations,” says Anwer Al-Dulaimi, cochair of the IEEE 5G/6G Innovation Testbed working group. Al-Dulaimi, an IEEE senior member, is a senior strategy manager of connectivity and Industry 4.0 for Veltris, in Toronto.

The testbed was launched this year with support from AT&T, Exfo, Eurecom, Veltris, VMWare, and Tech Mahindra.

The subscription-based testbed is available only to organizations. Customers receive their own private, secure session of the testing platform in the cloud along with the ability to add new users.

A variety of architectures and experiments

The platform eliminates the need for customers to travel to a location and connect to physical hardware, Al-Dulaimi says. That’s because its digital hub is based in the cloud, allowing companies, research facilities, and organizations to access it. The testbed allows customers to upload their own software components for testing.

“IEEE 5G/6G Innovation Testbed provides a unique platform for the service providers, and various vertical industries—including defense, homeland security, agriculture, and automotive—to experiment various use cases that can take advantage of advanced 5G technologies like ultra low latency, machine-to-machine type communications and massive broadband to help solve their pain points,” says IEEE Fellow Ashutosh Dutta, who is a cochair of the working group. Dutta works as chief 5G strategist at the Johns Hopkins University Applied Physics Laboratory, in Laurel, Md. He also heads the university’s Doctor of Engineering program.

“The IEEE 5G/6G Innovation Testbed creates an environment where industry can break new ground and work together to develop the next generation of technology innovations.”

The collaborative, secure, cloud-based platform also can emulate a 5G end-to-end network within the 3rd Generation Partnership Program (3GPP), which defines cellular communications standards.

“Companies can use the platform for testing, but they can also use the environment as a virtual hands-on showcase of new products, services, and network functions,” Dutta says.

In addition to the cloud-based end-to-end environment, the testbed supports other architectures including multiaccess edge computing for reduced latency, physical layer testing via 5G access points and phones installed at IEEE, and Open RAN (radio access network) environments where wireless radio functionality is disaggregated to allow for better flexibility in mixing hardware and software components.

A variety of experiments can be conducted, Al-Dulaimi says, including:

• Voice and video call emulation.
• Authentication and encryption impact evaluation across different 5G platforms.
• Network slicing.
• Denial-of-service attacks and interoperability and overload incidents.
• Verifying the functionality, compatibility, and interoperability of products.
• Assessing conformity of networks, components, and products.

The testbed group plans to release a new graphical user interface soon, as well as a test orchestration tool that contains hundreds of plug-and-play test cases to help customers quickly determine if their prototypes are working as intended across a variety of standards and scenarios. In addition to basic “sanity testing,” it includes tools to measure a proposed product’s real-time performance.

The proofs of concept—lessons learned from experiments—will help advance existing standards and create new ones, Dutta says, and they will expedite the deployment of 5G and 6G technologies.

The IEEE 5G/6G testbed is an asset that can be used by the academics, researchers, and R&D labs, he says, to help “close the gap between theory and practice. Students across the world can take advantage of this testbed to get hands-on experience as part of their course curriculum.”

Partnership with major telecom companies

The IEEE 5G/6G Innovation Testbed recently joined the Acceleration of Compatibility and Commercialization for Open RAN Deployments project. A public-private consortium, ACCORD includes AT&T, Verizon, Virginia Tech and the University of Texas at Dallas. The group is funded by the U.S. Department of Commerce’s National Telecommunications and Information Administration, whose programs and policymaking efforts focus on expanding broadband Internet access and adoption throughout the country.

“The 3GPP-compliant end-to-end 5G network is built with a suite of open-source modules, allowing companies to customize the network architecture and tailor their testbed environment according to their needs,” Al-Dulaimi says.

The testbed was made possible with a grant from the IEEE New Initiatives Committee, which funds potential IEEE services, products, and other creations that could significantly benefit members, the public, customers, or the technical community.

To get a free trial of the testbed, complete this form.

Watch this short demonstration of how the IEEE 5G/6G Innovation Testbed works. youtube

The field of wireless communication is constantly evolving, and engineers need to be aware of the latest improvements and requirements. To address their needs, the IEEE Communications Society is offering two exclusive training programs for individuals and technical teams.

The online Intensive Wireless Communications and Advanced Topics in Wireless course series are taught by experts in real time. Through lectures that include practical use cases and case studies, participants acquire knowledge that can be applied in the workplace. During the interactive, live courses, learners have the opportunity to engage directly with industry expert instructors and get answers to their questions in real time.

Recordings of the courses are available to facilitate group discussions of the materials and deepen understanding of concepts. Copies of the instructors’ slides are shared with participants, providing an ongoing resource for future reference.

The benefits of training as a team

“A team taking the courses together can benefit from discussing examples from the lectures and the practice questions,” instructor Alan Bensky says. “Attendees can also help each other better understand more difficult topics.” Bensky, who has more than 30 years of industry experience, teaches the Intensive Wireless Communications series.

Panteleimon Balis, an Advanced Topics in Wireless instructor, says taking the courses together as a team “fosters an aligned development of knowledge that enhances communication and collaboration within the team, leading to more effective problem-solving and decision-making.” Balis is a radio access network specialist who provides training on mobile and wireless communications technologies.

“The collective development of skill sets enables the team to apply the assimilated knowledge to real-world projects, driving innovation and efficiency within the organization,” he says. “Ultimately, attending these courses as a team not only strengthens individual competencies but also reinforces team cohesion and performance, benefiting the organization as a whole.”

Practical use cases to apply on the job

The following topics are covered in the Intensive Wireless Communications course, which is scheduled to be held in September and October:

• Fundamentals of wireless communication.
• Network and service architecture.
• Cellular networks.
• Noncellular wireless systems.

Several practical use cases are shared in the courses. Bensky notes, for example, that those working on Wi-Fi devices or network deployment likely will find the section on IEEE 802.11 especially useful because it covers the capabilities of the different amendments, particularly regarding data rate calculation and presentation of achievable rates.

“Attending these courses as a team not only strengthens individual competencies but also reinforces team cohesion and performance, benefiting the organization as a whole.” —Panteleimon Balis

The Advanced Topics in Wireless series, taught in October and November, includes these classes:

• 5G RAN and Core Network: Architecture, Technology Enablers, and Implementation Aspects.
• O-RAN: Disrupting the Radio Access Network through Openness and Innovation.
• Machine Type Communications in 5G and Beyond.

The inclusion of use cases, Balis says, brings significant value to the learning experience and helps with bridging the gap between theory and practice. In the O-RAN (open radio access network) module, for example, case studies analyze the pros and cons of early deployments in Japan and the United States.

As noted by the IEEE Standards Association, the key concept of O-RAN is opening the protocols and interfaces among the various building blocks—radios, hardware, and software—in the RAN.

The Advanced Topics in Wireless courses are scheduled to begin after the Intensive Wireless Communications series concludes.

More details about courses are available online, where you can learn how to offer the series to your team.

Skies over Tokyo are thick with air traffic these days amid an influx of international tourists. But one plane recently helped revive the dream of airborne Internet access for all. Researchers in Japan announced on 28 May that they have successfully tested 5G communications equipment in the 38 gigahertz band from an altitude of 4 kilometers.

The experiment was aimed at developing an aerial relay backhaul with millimeter-wave band links between ground stations and a simulated High-Altitude Platform Station (HAPS), a radio station aboard an uncrewed aircraft that stays aloft in the stratosphere for extended periods of time. A Cessna flying out of Chofu Airfield in western Tokyo was outfitted with a 38 GHz 5G base station and core network device, and three ground stations were equipped with lens antennas with automatic tracking.

With the Cessna as a relay station, the setup enabled communication between one ground station connected to the 5G terrestrial network and a terrestrial base station connected to a user terminal, according to a consortium of Japanese companies and the National Institute of Information and Communications Technology.

“We developed technology that enables communication using 5G [New Radio] by correctly directing 38 GHz beams toward three ground stations while adapting to the flight attitude, speed, direction, position, altitude, etc. during aircraft rotation,” said Shinichi Tanaka, a manager in broadcaster SKY Perfect JSAT’s Space Business Division. “We confirmed that the onboard system, designed for the stratosphere, has adequate communication and tracking performance even under the flight speed and attitude fluctuations of a Cessna aircraft, which are more severe than those of HAPS.”

The sharpest beam width of the ground station antenna is 0.8 degrees, and the trial demonstrated a tracking method that always captures the Cessna in this angular range, Tanaka added.

A Cessna [top left] carried a 38 GHz antenna [top right] during a flight, functioning as a 5G base station for receivers on the ground [bottom right]. The plane was able to connect to multiple ground stations at once [illustration, bottom left].NTT Docomo

Millimeter wave bands, such as the 38 GHz band, have the highest data capacity for 5G and are suited for crowded venues such as stadiums and shopping centers. When used outdoors, however, the signals can be attenuated by rain and other moisture in the atmosphere. To counter this, the consortium successfully tested an algorithm that automatically switches between multiple ground stations to compensate for moisture-weakened signals.

Unlike Google’s failed Loon effort, which focused on providing direct communication to user terminals, the HAPS trial is aimed at creating backhaul lines for base stations. Led by Japan’s Ministry of Internal Affairs and Communications, the experiment is designed to deliver high-speed, high-capacity communications both for the development of 5G and 6G networks as well as emergency response. The latter is critical in disaster-prone Japan—in January, communication lines around the Noto Peninsula on the Sea of Japan were severed following a magnitude-7 earthquake that caused over 1,500 casualties.

“This is the world’s first successful 5G communication experiment via the sky using the Q-band frequency,” said Hinata Kohara, a researcher with mobile carrier NTT Docomo’s 6G Network Innovation Department. “In addition, the use of 5G communication base stations and core network equipment on the aircraft for communication among multiple ground stations enables flexible and fast route switching of the ground [gateway] station for a feeder link, and is robust against propagation characteristics such as rainfall. Another key feature is the use of a full digital beamforming method for beam control, which uses multiple independent beams to improve frequency utilization efficiency.”

Doppler shift compensation was a challenge in the experiment, Kohara said, adding that the researchers will conduct further tests to find a solution with the aim of commercializing a HAPS service in 2026. Aside from SKY Perfect JSAT and NTT Docomo, the consortium includes Panasonic Holdings, known for its electronics equipment.

The HAPS push comes as NTT Docomo announced it has led another consortium in a $100 million investment in Airbus’ AALTO HAPS, operator of the Zephyr fixed-wing uncrewed aerial vehicle. The solar-powered wing can be used for 5G direct-to-device communications or Earth observation, and has set records including 64 days of stratospheric flight. According to Airbus, it has a reach of “up to 250 terrestrial towers in difficult mountainous terrain.” Docomo said the investment is aimed at commercializing Zephyr services in Japan, including coverage of rural areas and disaster zones, and around the world in 2026.