Method performed by user equipment, and user equipment

A method performed by a user equipment comprising:

• receiving a random access response, the random access response including a timing advance command indicating an index value TA in a form of a timing advance command field of 12 bits, the timing advance command corresponding to a Timing Advanced Group (TAG), the TAG being one of multiple TAGs;
• adjusting, based on a timing advance value NTA, uplink transmission timing for the TAG with a subcarrier spacing (SCS), the timing advance value NTA being determined based on (i) the index value TA and (ii) SCS configuration μ of the SCS;
• and
• determining a value N with respect to a minimum SCS among SCSs of all configured uplink bandwidth parts (UL BWPs) for all uplink carriers in the TAG and for all configured initial UL BWPs each provided by a higher-layer parameter initialuplinkBWP, wherein
• the value N is a maximum timing advance value in milliseconds that is providable by the timing advance command field of 12 bits, and
• the adjustment to the uplink transmission timing is applied from a starting point of an uplink slot, the uplink slot being based on (a) an uplink slot in which the timing advance command is received and (b) the value N.

A base station comprising:

• processing circuitry configured to generate a random access response including a timing advance command, the timing advance command indicating an index value TA in a form of a timing advance command field of 12 bits, the timing advance command corresponding to a Timing Advanced Group (TAG), the TAG being one of multiple TAGs, (i) the index value TA and (ii) a subcarrier spacing (SCS) configuration μ of the SCS being used by a user equipment to determine a timing advance value NTA based on which the user equipment determines uplink transmission timing for the TAG with the SCS;
• and
• transmitting circuitry configured to transmit the random access response to the user equipment, wherein
• the processing circuitry is configured to generate a higher-layer parameter initialuplinkBWP based on which the user equipment determines a value N with respect to a minimum subcarrier spacing (SCS) among SCSs of all configured UL BWPs for all uplink carriers in the TAG and for all configured initial UL BWPs each provided by the higher-layer parameter,
• the transmitting circuitry is configured to transmit the higher-layer parameter to the user equipment,
• the value N is a maximum timing advance value in milliseconds that is providable by the timing advance command field of 12 bits, and
• the adjustment to the uplink transmission timing is applied from a starting point of an uplink slot, the uplink slot being based on (a) an uplink slot in which the timing advance command is received and (b) the value N.

A method performed by a base station comprising:

• generating a random access response including a timing advance command, the timing advance command indicating an index value TA in a form of a timing advance command field of 12 bits, the timing advance command corresponding to a Timing Advanced Group (TAG), the TAG being one of multiple TAGs, (i) the index value TA and (ii) a subcarrier spacing (SCS) configuration μ of the SCS being used by a user equipment to determine a timing advance value NTA based on which the user equipment determines uplink transmission timing for the TAG with the SCS;
• transmitting the random access response to the user equipment;
• generating a higher-layer parameter initialuplinkBWP based on which the user equipment determines a value N with respect to a minimum subcarrier spacing (SCS) among SCSs of all configured UL BWPs for all uplink carriers in the TAG and for all configured initial UL BWPs each provided by the higher-layer parameter;
• and
• transmitting the higher-layer parameter to the user equipment, wherein
• the value N is a maximum timing advance value in milliseconds that is providable by the timing advance command field of 12 bits, and
• the adjustment to the uplink transmission timing is applied from a starting point of an uplink slot, the uplink slot being based on (a) an uplink slot in which the timing advance command is received and (b) the value N.