Researcher
研究者名
Harada, Hiroshi
Overview
A research group led by Professor Hiroshi Harada of the Graduate School of Informatics at Kyoto University has developed a wireless communication system compliant with the international wireless communication standard "Wi-SUN FAN" for VHF-band (170 MHz and 220 MHz bands) narrowband IoT communication systems (hereinafter "VHF-IoT"), for which the Information and Communications Council of the Ministry of Internal Affairs and Communications issued a partial report in December 2025. The developed system is expected to achieve long-distance transmission over more than 10 km. The group also developed a highly efficient video compression and transmission system capable of transmitting video at the limited data rates available with VHF-IoT. By installing these systems on a drone, the group successfully demonstrated wireless transmission of live HD (1,280 × 720 pixels) camera video at 10 fps from a drone in actual flight.
Key points
- Developed a wireless communication system compliant with the international wireless communication standard Wi-SUN FAN, which uses OFDM, for VHF-IoT in the 170 MHz and 220 MHz bands, which are well suited to long-distance communication. The system achieves high-speed transmission at 600 kbit/s with an occupied bandwidth of 400 kHz and 2,400 kbit/s with an occupied bandwidth of 1,200 kHz.
- Successfully transmitted live HD (1,280 × 720 pixels) camera video at 10 fps from a drone in flight using an occupied bandwidth of 400 kHz.
- In addition to highly efficient video compression, developed packet aggregation for efficiently transmitting multiple video packets and proprietary communication control technology for transmitting important video frames with high quality and efficiency, thereby achieving stable live video transmission even at limited data rates.
- Applied Wi-SUN FAN, which supports autonomous network formation and multi-stage multi-hop communication, to the VHF band and demonstrated live video transmission from a drone in flight to a ground station, with a view to deployment for wide-area communications during disasters and in mountainous areas.
