Radio terminal, base station, and radio communication system configured to scramble or spread signal transmitted using line identification information related to setting of host line between base station and host node

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.