Propagation Measurements Of Multi-Hop Command And Telemetry Communications System In The 169 Mhz Band For Drones

The 169 MHz band was assigned for unmanned vehicles such as robots and drones by the Ministry of Internal Affairs and Communications (MIC) in 2016 in Japan, according to the reallocation of the TV band from VHF (analog) to UHF (digital). This band is expected to have a long range and good diffraction characteristics during drone operation over a long range with obstacles such as buildings, trees, or terrains. In this paper, we present the prototype system and its propagation experiments of command and telemetry communications at 169 MHz, which is added to a multi-hop communication unit in the 920 MHz band developed previously to enhance the beyond line-of-sight (BLOS) operation performance for drones.