Terminal apparatus, base station apparatus, communication method, and integrated circuit

A base station apparatus, comprising:

• generation circuitry configured to generate an RRC reconfiguration message including a Data Radio Bearer (DRB) configuration, wherein the DRB configuration includes configuration information indicating whether or not a Service Data Adaptation Protocol (SDAP) function is configured, the SDAP function includes QoS Flow Identifier (QFI) to the DRB mapping, and the QFI is QoS information of 5G Core (5GC);
• and
• transmitting circuitry configured to transmit the RRC reconfiguration message to a terminal apparatus, wherein
• the RRC reconfiguration message including the DRB configuration causes the terminal apparatus to determine, in accordance with the DRB configuration, whether to configure the SDAP function.

A method performed by a base station apparatus, the method comprising:

• generating an RRC reconfiguration message including a Data Radio Bearer (DRB) configuration, wherein the DRB configuration includes configuration information indicating whether or not a Service Data Adaptation Protocol (SDAP) function is configured, the SDAP function includes QoS Flow Identifier (QFI) to the DRB mapping, and the QFI is QoS information of 5G Core (5GC);
• and
• transmitting the RRC reconfiguration message to a terminal apparatus, wherein
• the RRC reconfiguration message including the DRB configuration causes the terminal apparatus to determine, in accordance with the DRB configuration, whether to configure the SDAP function.