A highly robust communication system capable of stably realizing a three-dimensionalized network over a wide area can be provided, in which a propagation delay is low, a simultaneous connection with a large number of terminals in a wide-range area and a high-speed communication can be performed, and a system capacity per unit area is large, in radio communications with terminal apparatuses including devices for the IoT, in mobile communications of the fifth generation or the like. The communication system comprises a plurality of radio relay for relaying a radio communication between a terrestrial base station and a terminal apparatus. The plurality of radio relay stations include a plurality of first radio relay stations capable of communicating with each other, each first radio relay station being provided in a floating object controlled to be located in a floating airspace with an altitude less than or equal to 100 [km] by an autonomous control or an external control, and a second radio relay station for relaying a communication between the plurality of first radio relay stations and the terrestrial base station, the second radio relay station being provided in a floating object moored on the ground or the sea so as to be located in a floating airspace with an altitude less than or equal to 100 [km].
展开▼