According to the present application, a base station device is configured to manage a vertically-oriented cell and a ground cell with respective IDs used to identify each cell, to determine whether or not a counterpart terminal device is an aircraft terminal device for air-to-ground communication based on a terminal ID included in a message received therefrom, and to control communication with the counterpart terminal device such that, if the counterpart terminal device is an aircraft terminal device, the base station selects the vertically-oriented cell as a connection destination of the counterpart terminal device and transmits a connection instruction message including a cell ID of the vertically-oriented cell to the counterpart terminal device, otherwise, the base station selects the ground cell as a connection destination of the counterpart terminal device and transmits a connection instruction message including a cell ID of the ground cell to the counterpart terminal device.