Radio communication system

A radio communication system comprising:

• a user equipment;
• a base station configured to perform radio communication with the user equipment;
• a first management apparatus configured to be communicatively connected to the base station and manage the user equipment according to a first radio access technology (RAT);
• and
• a second management apparatus configured to be communicatively connected to the base station and manage the user equipment according to a second RAT different from the first RAT,
• wherein the base station includes
• a communication control unit that controls radio communication with the user equipment, and
• a location registration information transmission unit that transmits first location registration information of the first management apparatus and second location registration information of the second management apparatus, and
• wherein the user equipment includes
• a location registration information acquisition unit that acquires the first location registration information and the second location registration information from the base station,
• a location registration information management unit that retains location registration information,
• a location registration necessity determination unit that determines that location registration in the first or second management apparatus is necessary based on the retained location registration information and the location registration information corresponding to the management apparatus managing the user equipment between the acquired first location registration information and second location registration information, and
• a location registration processing unit that performs location registration in the first or second management apparatus when it is determined that the location registration in the first or second management apparatus is necessary.