Base station apparatus, terminal apparatus, and communication method

A terminal device configured to communicate with a base station device, the terminal device comprising:

• a receiver configured to
• receive, from the base station device, a configuration for an initial UpLink (UL) Band Width Part (BWP) and a configuration for an additional UL BWP via a Radio Resource Control (RRC) message, and
• receive, from the base station device, a Random Access Response (RAR) message including a RAR UL grant;
• processing circuitry configured to switch an active UL BWP between the initial UL BWP and the additional UL BWP;
• and
• a transmitter configured to transmit, to the base station device, a Physical Uplink Shared CHannel (PUSCH) in the active UL BWP,
• wherein:
• one of the initial UL BWP and the additional UL BWP is activated as the active UL BWP,
• the PUSCH is scheduled by using the RAR UL grant,
• a first field with a fixed bit size included in the RAR UL grant is used to indicate frequency resource allocation of the PUSCH,
• the processing circuitry is further configured to truncate bits from the first field or insert bits into the first field and to interpret the truncated first field or the expanded first field as a field indicating the frequency resource allocation of the PUSCH,
• in a case that the initial UL BWP is the active UL BWP, to truncate bits from the first field or to insert bits into the first field is done by using a size of the initial UL BWP, and
• in a case that the additional UL BWP is the active UL BWP, to truncate bits from the first field or to insert bits into the first field is done by using the size of the initial UL BWP.