1. A communication system comprising:
a communication terminal device; and
a plurality of base stations configured to perform radio communication with the communication terminal device, wherein
the plurality of base stations include a master base station and a secondary base station configuring dual connectivity with respect to the communication terminal device, and
when failure occurs in a secondary cell group (SCG) used for communication between the communication terminal device and the secondary base station, the master base station acquires latest SCG configuration.
2. The communication system according to claim 1, wherein
when failure occurs in the SCG, the communication terminal device notifies the master base station of the latest SCG configuration.
3. The communication system according to claim 1, wherein
when failure occurs in the SCG, the master base station enquires of the secondary base station about the latest SCG configuration, and the secondary base station notifies the master base station of the latest SCG configuration in response to an enquiry from the master base station.
4. A base station configured to perform radio communication with a communication
terminal device, wherein
the base station operates as a master base station of dual connectivity with respect to the communication terminal device, and
when failure occurs in a secondary cell group (SCG) used for communication between the communication terminal device and a secondary base station of the dual connectivity, the base station acquires latest SCG configuration.