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On March 18, 2021, SoftBank Corp. (TOKYO: 9434) and Nikon Corporation jointly held a press conference to unveil a new technology they developed for optical wireless communications. With the successful demonstration of their “tracking optical wireless communication technology,” both companies marked a world first.
A new communication technology focused on light
(From left) SoftBank’s Hironobu Tamba, Vice President and Head of the IT-OT Innovation Division, and Nikon’s Yuichi Shibazaki, Corporate Vice President and General Manager of Next Generation Project Division, at the press conference.
Wireless communications use radio waves in frequency bands allocated to each telecommunications carrier. However, while there are a limited number of frequency bands available, demand for high-volume communications is on the increase.
Hironobu Tamba, Head of SoftBank’s IT-OT Innovation Division, Hironobu Tamba, elaborated. “In preparation for the 6G era, R&D for communications technologies that use infrared and sub-millimeter waves is gathering momentum. In our exploration of new areas to provide more sustainable communications with higher added value, we chose to focus on light. I’m not saying that light will replace radio waves, but we expect the future will see light and radio waves supplementing each other to realize telecommunications that meet diverse needs.”
Stressing the new technology’s potential, Tamba said, “A new dynamic will be introduced to the world of telecommunications, as the prevailing wisdom in radio-wave communications evolves and takes on the form of optical wireless communications.” Optical wireless communications are expected to ensure secure, low-latency, high-volume communications. If successfully put to practical use, the technology could be used for various applications that require stable communications, including autonomous driving, drones, and home-delivery robots. It could also be used in underwater and underground environments.
Features of optical wireless communications
Radio waves tend to interfere with each other in different frequency bands, thereby generating noise. On the other hand, light has properties different from those of radio waves, and the two are capable of co-existing without interfering with each other. However, another property light has is “rectilinear propagation,” and this has significantly hampered expansion of its use in applications until now.
- Benefits of optical wireless communications
Optical wireless communications will not interfere with existing radio-wave communications. Light enables wireless communications without interference from radio waves in the atmosphere. Additionally, as optical wireless communications are more secure, instead of using radio waves, light can be utilized in specific areas of communication where security is a priority.
- Issues facing optical wireless communications
Light travels in a straight line. Because of this characteristic, optical wireless communications are susceptible to disruption if the position or direction of either the transmitter or receiver fluctuates in the slightest. This makes it difficult for optical wireless communications to be used between two moving objects.
In order to exploit the potential of optical wireless communications further, tracking technology must be integrated to supplement application in communication devices.
- Benefits of optical wireless communications
Optical wireless communications will not interfere with existing radio-wave communications.Light enables wireless communications without interference from radio waves in the atmosphere. Additionally, as optical wireless communications are more secure, instead of using radio waves, light can be utilized in specific areas of communication where security is a priority. - Issues facing optical wireless communications
Light travels in a straight line. Because of this characteristic, optical wireless communications are susceptible to disruption if the position or direction of either the transmitter or receiver fluctuates in the slightest. This makes it difficult for optical wireless communications to be used between two moving objects.
In order to exploit the potential of optical wireless communications further, tracking technology must be integrated to supplement application in communication devices.
Nikon chosen as partner owing to its expertise in optical wireless communications
Tamba then explained how the latest joint experiment developed. “Despite the potential of optical wireless communications, we needed a tracking technology to resolve the issues caused by the ‘rectilinear propagation’ of light. To that end, we focused on combining two elemental technologies, namely ‘image recognition’ and ‘gimbal.’ In 2019, we successfully proved the principles of a short-distance tracking technology and obtained patents. We thought that this technology could be applied for purposes other than telecommunications. In order to speed up the process of applying this technology for practical use, we decided to collaborate in joint experiments with Nikon, a company that has a competitive edge in optical applications and image recognition technologies.”
Two elemental technologies used for tracking optic wireless communication technology
- Image recognition
This technology enables the recognition of objects with a field-of-vison equivalent to that of human eyes, thereby allowing large volumes of information to be processed. It also enables the identification of other communication providers, and the detection of people and obstacles. - Gimbal
A gimbal permits rotation of an object about an axis and can therefore move in a wide area. Additionally, it does not restrict the size or type of object that can be mounted, so it can be easily used for other applications where optical wireless communication equipment is not mounted.
It is believed that tracking technology can be utilized in various ways. For example, it may reduce the time required for preparing mobile base station vehicles for wireless relays. It is also anticipated the technology can be applied to provide mobile base stations with backhaul. In terms of wireless power supply, which is essential for realizing smart cities, pinpoint power supply for remote stationary or moving objects will be made possible. Furthermore, when broadcasting soccer matches, by combining a fixed camera showing the entire pitch and a gimbal-mounted camera, image recognition technology enables the up-close tracking of a given player. The technology has vast potential.
Tracking technology is similar to human eye movement
Subsequently, Nikon’s Yuichi Shibazaki, Corporate Vice President and General Manager of Next Generation Project Division provided an explanation of the tracking optical wireless communication equipment. While Nikon is well-recognized as a camera manufacturer, the company’s business domains also span healthcare, precision machinery, and industrial devices and digital solutions in addition to images. These businesses are based on technologies that utilize optical and precision technologies, which are also technologies used for the tracking wireless communication described here.
Shibazaki explained how the communication system works. “You can see that this demonstration robot has a shape like that of a human face. In the middle of the equivalent of a human forehead, is an optical wireless communication module provided by SoftBank. Underneath it, there is a camera that serves as an eye, albeit only one. Using the camera, the robot recognizes the image of another robot and tracks it. The robot’s visual sensing function precisely controls its parts from the neck up, and when the two robots face each other, communication is maintained. That’s how it works. Imagine that the two robots are emitting beams from their foreheads to understand each other using telepathy. In this experiment, Nikon’s existing product, ‘Laser Radar’ spatial distance measuring equipment, was applied, saving us a great deal of time in development.”
There are two major technologies used in the system. One is a target recognition technology that utilizes AI image processing to detect a target from the background. High levels of recognition rates are ensured through the learning of a number of patterns, including background reflections such as wiring and structures, background brightness, distance, and focus. Additionally, the iconic yellow board invented after a trial-and-error process helped to improve recognition rates further thanks to a unique target design.
The other is a precision tracking technology. Simply aligning the two cameras’ axes is not enough to make the wireless communication modules located above them to face each other. Therefore, the camera axes are controlled according to the other robot’s position. Shibazaki expressed his strong belief in the technology’s potential, commenting, “Successful target recognition was achieved with two robots placed 100m apart, a maximum distance for the specifications of the communication equipment used. I’m confident that this technology will lay the foundation for the achievement of 1 (km)/1G (bps) in the future.”
R&D continues to meet more sophisticated requirements
Closing the event, the two speakers touched on their companies’ efforts to effectively demonstrate technologies that mount optical wireless communication devices on mobile objects despite the various difficulties they have faced so far. “This technology is still in its infancy. With the aim of achieving practical use in several years’ time, we’ll identify targets for business applications while examining various use cases. We’re committed to increasing speed and reducing size and cost to meet different requirements” they said.
(Original article posted on March 25, 2021)
by SoftBank News Editors
