Terminal apparatus, base station apparatus, and communication method

1. A terminal apparatus comprising:

reception circuitry configured to receive a message including first information, second information, and third information, the first information being for setting a first set of downlink bandwidth parts (BWPs) for a primary cell, the second information indicating a first downlink BWP to be activated among the first set of downlink BWPs, and the third information being for setting a second set of downlink BWPs for a secondary cell; and

medium access control layer processing circuitry configured to:

deactivate a second downlink BWP that has been activated in the primary cell, and activate the first downlink BWP,

wherein the reception circuitry is configured to receive an activation/deactivation Medium Access Control (MAC) Control Element (CE) indicating activation of the secondary cell;

the medium access control layer processing circuitry is configured to:

activate a third BWP in the second set of downlink BWPs in a case that the activation/deactivation MAC CE is received and the secondary cell has not been activated, and

not to activate the third downlink BWP in a case that the activation/deactivation MAC CE is received, and the secondary cell and a fourth downlink BWP of the secondary cell have been activated before the activation/deactivation MAC CE is received; and

the third downlink BWP is different from the fourth downlink BWP.

2. A base station apparatus comprising:

transmission circuitry configured to transmit, to a terminal apparatus, a message including first information, second information, and third information, the first information being for setting a first set of downlink bandwidth parts (BWPs) for a primary cell, the second information indicating a first downlink BWP among the first set of downlink BWPs, and the third information being for setting a second set of downlink BWPs for a secondary cell; and

medium access control layer processing circuitry configured to cause the terminal apparatus to:

deactivate a second downlink BWP that has been activated in the primary cell, and activate the first downlink BWP,

wherein the transmission circuitry is configured to transmit an activation/deactivation Medium Access Control (MAC) Control Element (CE) indicating activation of the secondary cell to the terminal apparatus;

the medium access control layer processing circuitry is configured to control a downlink BWP to be activated in the second set of downlink BWPs by transmitting the activation/deactivation MAC CE;

a third downlink BWP in the second set of downlink BWPs is activated by the terminal apparatus in a case that the terminal apparatus receives the activation/deactivation MAC CE and the secondary cell has not been activated;

the third downlink BWP in the second set of downlink BWPs is not activated by the terminal apparatus in a case that the terminal apparatus receives the activation/deactivation MAC CE, and the secondary cell and a fourth downlink BWP of the secondary cell have been activated before the activation/deactivation MAC CE is receive; and

the third downlink BWP is different from the fourth downlink BWP.

3. A communication method used for a terminal apparatus, the communication method comprising:

receiving a message including first information, second information, and third information, the first information being for setting a first set of downlink bandwidth parts (BWPs) for a primary cell, the second information indicating a first downlink BWP to be activated among the first set of downlink BWPs, and the third information being for setting a second set of downlink BWPs;

deactivating a second downlink BWP that has been activated in the primary cell;

activating the first downlink BWP;

receiving an activation/deactivation Medium Access Control (MAC) Control Element (CE) indicating activation of the secondary cell;

activating a third downlink BWP in the second set of downlink BWPs in a case that the activation/deactivation MAC CE is received and the secondary cell has not been activated; and

not activating the third downlink BWP in a case that the activation/deactivation MAC CE is received, and the secondary cell and a fourth downlink BWP of the secondary cell have been activated before the activation/deactivation MAC CE is received, wherein

the third downlink BWP is different from the fourth downlink BWP.

4. A communication method used for a base station apparatus, the communication method comprising:

transmitting, to a terminal apparatus, a message including first information, second information, and third information, the first information being for setting a first set of downlink bandwidth parts (BWPs) for a primary cell, the second information indicating a first downlink BWP to be activated among the set of downlink BWPs, and the third information being for setting a second set of downlink BWPs for a secondary cell;

causing the terminal apparatus to deactivate a second downlink BWP which has been activated in the primary cell, and activate the first downlink BWP;

transmitting an activation/deactivation Medium Access Control (MAC) Control Element (CE) indicating activation of the secondary cell to the terminal apparatus; and

controlling a downlink bandwidth part (BWP) to be activated in multiple downlink BWPs included in the secondary cell by transmitting the activation/deactivation MAC CE, wherein

a third downlink BWP in the second set of downlink BWPs is activated by the terminal apparatus in a case that the terminal apparatus receives the activation/deactivation MAC CE and the secondary cell has not been activated,

the third downlink BWP in the second set of downlink BWPs is not activated by the terminal apparatus in a case that the terminal apparatus receives the activation/deactivation MAC CE, and the secondary cell and a fourth downlink BWP of the secondary cell have been activated before the activation/deactivation MAC CE is received, and

the third downlink BWP is different from the fourth downlink BWP.