A radio terminal includes a radio reception device that receives line identification information related to a setting of a host line between a base station and a host node, and a radio signal from the base station, when a radio line between the radio terminal and the base station is disconnected, and the host line used by the radio terminal to communicate via the base station is maintained, a control device that scrambles or spreads a signal to be transmitted to another communication device or the base station, using the line identification information, and a radio transmission device that transmits the scrambled or spread signal to the base station.