A research group led by Professor Hiroshi Harada of the Graduate School of Informatics at Kyoto University has developed a wireless system compatible with the VHF band (220 MHz band) for narrowband IoT (Internet of Things) communication systems, partially based on recommendations issued by the Information and Communications Council of the Ministry of Internal Affairs and Communications in December 2025. The developed system is based on the Wi-SUN system, which complies with the international standard "IEEE 802.15.4 SUN" and has a proven track record in applications such as smart meters. Using this system, the research group successfully demonstrated long-distance video transmission over approximately 34 km while utilizing a narrow channel bandwidth of only 400 kHz. Based on these demonstration results, the technology is expected to enable new applications involving video transmission in airspace, maritime environments, and outer space, where coverage by conventional mobile communication systems has traditionally been difficult.
Key points
- Developed a narrowband IoT wireless system operating in the VHF band (220 MHz band), for which technical specifications were established in December 2025, based on the Wi-SUN system compliant with the international standard "IEEE 802.15.4 SUN", which has a proven track record in applications such as smart meters
- Enabled wireless transmission of high-definition video over a narrow 400 kHz channel bandwidth through the use of highly efficient video compression technology
- Successfully demonstrated long-distance wireless video transmission between locations approximately 34 km apart
