The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method for user equipment according to an embodiment of the present disclosure comprises the steps of: receiving, from a base station, first information indicating activation or deactivation of at least one uplink cell of a first cell group; transmitting, to the base station, second information indicating that the first information has been received; identifying, on the basis of the first information, whether or not, from among the at least one uplink cell, a first uplink cell has been activated; and if the first uplink cell has been activated, carrying out an uplink transmission via the first uplink cell.