Communication system, base station device and communication terminal device

A base station device configured to perform radio communication with a communication terminal device, wherein

• the base station device operates as a secondary base station device configuring at least one bearer for the communication terminal device with a master base station device,
• when the base station device detects generation of downlink data for the communication terminal device being in an RRC_INACTIVE state, the base station device notifies the master base station device of the generation of the downlink data,
• when the master base station device receives the notification about the generation of the downlink data, the master base station device transmits paging to the communication terminal device, and
• the paging includes at least one of
• information about connection between the communication terminal device and the master base station device, and
• information about connection between the communication terminal device and the base station device.

A base station device configured to perform radio communication with a communication terminal device, wherein

• the base station device operates as a master base station device configuring at least one bearer for the communication terminal device with a secondary base station device,
• when the secondary base station device detects generation of downlink data for the communication terminal device being in an RRC_INACTIVE state, the secondary base station device notifies the base station device of the generation of the downlink data,
• when the base station device receives the notification about the generation of the downlink data, the base station device transmits paging to the communication terminal device, and
• the paging includes at least one of
• information about connection between the communication terminal device and the base station device, and
• information about connection between the communication terminal device and the secondary base station device.

A communication terminal device configured to perform radio communication with a plurality of base station devices, wherein

• the plurality of base station devices include a master base station device and a secondary base station device that are configured to provide at least one bearer for the communication terminal device,
• when the secondary base station device detects generation of downlink data for the communication terminal device being in an RRC_INACTIVE state, the secondary base station device notifies the master base station device of the generation of the downlink data,
• when the master base station device receives the notification about the generation of the downlink data, the master base station device transmits paging to the communication terminal device, and
• when the communication terminal device receives the paging, the communication terminal device transmits a request for restoration to an RRC_CONNECTED state to the master base station device,
• the paging including at least one of
• information about connection between the communication terminal device and the master base station device, and
• information about connection between the communication terminal device and the secondary base station device.