The team of Professor Hiroshi Harada, of Kyoto University’s Graduate School of Informatics, has developed a wireless system based on the international Wi-SUN FAN standard for Internet of Things networks in the VHF band, at frequencies of 170 MHz and 220 MHz. The system is expected to allow transmissions over more than 10 kilometres.
Because these networks offer low speeds, the researchers also created their own video compression and transmission system, which groups data packets and sends the most important images at higher quality. The system reaches 600 kbit/s with a bandwidth of 400 kHz and 2400 kbit/s with 1200 kHz.
Mounted on a drone, the equipment sent live high-definition video (1280 x 720 pixels, at 10 frames per second) to a ground station during a real flight. The technology also allows the network to organise itself and relay information through several intermediate points.
The researchers point to long-range communications in disaster situations and in mountainous regions as applications.
