A method for enhancing Bandwidth Part (BWP) operation towards Secondary Cell (SCell) dormancy indication is proposed. A User Equipment (UE) detects a Downlink Control Information (DCI) format including an SCell dormancy indication that indicates an active BWP change for a serving cell. The UE performs BWP switching for the serving cell in response to the DCI format. The UE stops transmission or reception in the serving cell during a time duration from a slot containing a last symbol of the DCI format, wherein the time duration includes a first period of time of delay for the BWP switching and a second period of time of interruption to other active serving cells.

A method for enhancing Bandwidth Part (BWP) operation towards Secondary Cell (SCell) dormancy indication is proposed. A User Equipment (UE) detects a Downlink Control Information (DCI) format including an SCell dormancy indication that indicates an active BWP change for a serving cell. The UE performs BWP switching for the serving cell in response to the DCI format. The UE stops transmission or reception in the serving cell during a time duration from a slot containing a last symbol of the DCI format, wherein the time duration includes a first period of time of delay for the BWP switching and a second period of time of interruption to other active serving cells.

Certain aspects of the present disclosure provide techniques for configuring monitoring of downlink control information (DCI) for a source cell and a target cell during make-before-break (MBB) handover.

Certain aspects of the present disclosure provide techniques for configuring monitoring of downlink control information (DCI) for a source cell and a target cell during make-before-break (MBB) handover.

A terminal apparatus is provided. The terminal apparatus includes a receiver configured to receive a first message from a base station apparatus, and a processing unit configured to modify first data radio bearer configuration configured for the terminal apparatus, based on the first message. A first PDCP entity is reconfigured as a packet data convergence protocol (PDCP) entity for the first data radio bearer. A first secrecy key for a source and a second secrecy key for a target are configured for the first PDCP entity as secrecy keys for the first data radio bearer. In a case that the first message includes first information and second information, the second secrecy key for the target of the first PDCP entity is configured based on the second information. In a case that the first message does not include the first information, the first secrecy key for the source is applied to the second secrecy key for the target of the first PDCP entity.

A terminal apparatus is provided. The terminal apparatus includes a receiver configured to receive a first message from a base station apparatus, and a processing unit configured to modify first data radio bearer configuration configured for the terminal apparatus, based on the first message. A first PDCP entity is reconfigured as a packet data convergence protocol (PDCP) entity for the first data radio bearer. A first secrecy key for a source and a second secrecy key for a target are configured for the first PDCP entity as secrecy keys for the first data radio bearer. In a case that the first message includes first information and second information, the second secrecy key for the target of the first PDCP entity is configured based on the second information. In a case that the first message does not include the first information, the first secrecy key for the source is applied to the second secrecy key for the target of the first PDCP entity.

A terminal apparatus for communicating with a base station apparatus is provided. The terminal apparatus includes a receiver configured to receive, from the base station apparatus, a Radio Resource Control (RRC) reconfiguration message including a parameter related to first configuration, and a processing unit configured to perform configuration in accordance with the RRC reconfiguration message received. In a case that a first timer of an RRC protocol expires, a radio link failure of a source primary cell is not detected, and configuration related to Dual Active Protocol Stack (DAPS) handover is performed for the terminal apparatus, the processing unit stops all of timers configured for a Radio Link Control (RLC) entity of a Signaling Radio Bearer (SRB) in the source primary cell, resumes the SRB suspended in the source primary cell, and transmits an RRC message for notifying the base station apparatus that the DAPS handover has failed.

A terminal apparatus for communicating with a base station apparatus is provided. The terminal apparatus includes a receiver configured to receive a first message from the base station apparatus, and a processing unit configured to establish a second packet data convergence protocol (PDCP) entity with a configuration identical to a configuration of a first PDCP entity for a first signaling radio bearer, based on a fact that a first configuration is configured. The first configuration is configured based on the first message.

A terminal apparatus for communicating with a base station apparatus is provided. The terminal apparatus includes a receiver configured to receive a first message from the base station apparatus, and a processing unit configured to establish a second packet data convergence protocol (PDCP) entity with a configuration identical to a configuration of a first PDCP entity for a first signaling radio bearer, based on a fact that a first configuration is configured. The first configuration is configured based on the first message.

A terminal apparatus for communicating with a base station apparatus is provided. The terminal apparatus includes a receiver configured to receive a Radio Resource Control (RRC) reconfiguration message including a parameter related to a first configuration from the base station apparatus, and a processing unit configured to perform configuration in accordance with the RRC reconfiguration message received. In a case that a first timer of an RRC protocol expires, a radio link failure of a source primary cell is not detected, and configuration related to Dual Active Protocol Stack (DAPS) handover is performed for the terminal apparatus, the processing unit reconfigures all of state variables configured for a Radio Link Control (RLC) entity of a Signaling Radio Bearer (SRB) in the source primary cell to respective initial values, resumes the SRB suspended in the source primary cell, and transmits an RRC message for notifying the base station apparatus that the DAPS handover has failed.