Terminal apparatus, base station apparatus, and method

A base station apparatus for communicating with a terminal apparatus, the base station apparatus comprising:

• transmission circuitry configured to transmit a Radio Resource Control (RRC) reconfiguration message including a Data Radio Bearer (DRB) configuration to the terminal apparatus;
• and
• processing circuitry configured to cause the terminal apparatus to perform processing by including the DRB configuration in the RRC reconfiguration message, wherein
• the processing comprises:
• determining whether a DRB identity included in the DRB configuration is not part of a current configuration of the terminal apparatus,
• determining whether a Service Data Adaptation Protocol (SDAP) configuration is included in the DRB configuration,
• determining whether an SDAP entity corresponding to a Protocol Data Unit (PDU) session indicated by a PDU session information element included in the SDAP configuration does not exist after determining whether the SDAP configuration is included in the DRB configuration,
• establishing the SDAP entity based on determination that the DRB identity included in the DRB configuration is not part of the current configuration of the terminal apparatus, the SDAP configuration is included in the DRB configuration, and the SDAP entity corresponding to the PDU session indicated by the PDU session information element included in the SDAP configuration does not exist after determining whether the SDAP configuration is included in the DRB configuration, and
• indicating establishment of a user-plane resource for the PDU session to an upper layer based on determination that the DRB identity included in the DRB configuration is not part of the current configuration of the terminal apparatus, the SDAP configuration is included in the DRB configuration, the SDAP entity corresponding to the PDU session indicated by the PDU session information element included in the SDAP configuration does not exist after determining whether the SDAP configuration is included in the DRB configuration, and that the SDAP entity corresponding to the PDU session indicated by the PDU information element included in the SDAP configuration does not exist before the terminal apparatus receives the RRC reconfiguration message.

A communication method used by a terminal apparatus for communicating with a base station apparatus, the communication method comprising:

• receiving a Radio Resource Control (RRC) reconfiguration message including a Data Radio Bearer (DRB) configuration from the base station apparatus;
• determining whether a DRB identity included in the DRB configuration is not part of a current configuration of the terminal apparatus,
• determining whether a Service Data Adaptation Protocol (SDAP) configuration is included in the DRB configuration,
• determining whether an SDAP entity corresponding to a Protocol Data Unit (PDU) session indicated by a PDU session information element included in the SDAP configuration does not exist after determining whether the SDAP configuration is included in the DRB configuration,
• establishing the SDAP entity based on determination that the-a DRB identity included in the DRB configuration is not part of the current configuration of the terminal apparatus, the SDAP configuration is included in the DRB configuration, and the SDAP entity corresponding to the PDU session indicated by the PDU session information element included in the SDAP configuration does not exist after determining whether the SDAP configuration is included in the DRB configuration;
• determining whether the SDAP entity corresponding to the PDU session indicated by the PDU information element included in the SDAP configuration does not exist before receiving the RRC reconfiguration message;
• and
• indicating establishment of a user-plane resource for the PDU session to an upper layer based on determination that the DRB identity included in the DRB configuration is not part of the current configuration of the terminal apparatus, the SDAP configuration is included in the DRB configuration, the SDAP entity corresponding to the PDU session indicated by the PDU session information element included in the SDAP configuration does not exist after determining whether the SDAP configuration is included in the DRB configuration, and that the SDAP configuration does not exist, and the SDAP entity corresponding to the PDU session indicated by the PDU session information element included in the SDAP configuration does not exist before receiving the RRC reconfiguration message.