Radio communication system, base station apparatus, radio terminal, and communication control method

A base station apparatus comprising:

• a memory;
• and
• at least one hardware processer coupled to the memory and configured to execute modules comprising a communication controller configured to control dual connectivity involving a bearer split in which a first network bearer between a radio terminal and a core network is split over the base station apparatus and a neighbor base station,
• wherein the communication controller is configured to receive, from the neighbor base station, bearer split status information about communication of the first network bearer in the neighbor base station, and to perform control of an access stratum related to the first network bearer.

A base station apparatus comprising:

• a memory;
• and
• at least one hardware processer coupled to the memory and configured to execute modules comprising a communication controller configured to control dual connectivity involving a bearer split in which a first network bearer between a radio terminal and a core network is split over the base station apparatus and a neighbor base station, wherein
• the communication controller is configured to send, to the neighbor base station, bearer split status information about communication of the first network bearer in the base station apparatus, and
• the bearer split status information triggers the neighbor base station to perform control of an access stratum related to the first network bearer.

A communication control method comprising:

• starting, by a second base station, communication of dual connectivity involving a bearer split in which a first network bearer between a radio terminal and a core network is split over a first base station and the second bases station;
• and
• transmitting, to the first base station, bearer split status information about communication of the first network bearer in the second base station,
• wherein the bearer split status information triggers the first base station to perform control of an access stratum related to the first network bearer.