A wireless communication terminal that wirelessly communicates with a base wireless communication terminal, the wireless communication terminal comprising: a transceiver ; and a processor for processing a radio signal received through the transceiver or a radio signal to be transmitted through the transceiver , wherein the processor is configured to: transmit, to the base wireless communication terminal , a trigger-based physical layer protocol data unit, PPDU, using the transceiver , switch an enhanced distributed channel access, EDCA, parameter set, which is a set of parameters used for the channel access, from a first EDCA parameter set to a second EDCA parameter set based on whether the base wireless communication terminal triggers a multi-user uplink transmission participation of the wireless communication terminal , set a second EDCA parameter set timer based on whether a response to a MAC protocol data unit, MPDU, included in the trigger-based PPDU is received, when the second EDCA parameter set timer expires, terminate an application of the second EDCA parameter set, calculate a random integer value within a contention window, CW, set a backoff timer based on the random integer value, and access a channel based on the back off timer and a predetermined slot time, wherein each of the first and second EDCA parameter sets comprises a minimum value, CWmin, of the CW and a maximum value, CWmax, of the CW. a transceiver ; and a processor for processing a radio signal received through the transceiver or a radio signal to be transmitted through the transceiver , wherein the processor is configured to: transmit, to the base wireless communication terminal , a trigger-based physical layer protocol data unit, PPDU, using the transceiver , switch an enhanced distributed channel access, EDCA, parameter set, which is a set of parameters used for the channel access, from a first EDCA parameter set to a second EDCA parameter set based on whether the base wireless communication terminal triggers a multi-user uplink transmission participation of the wireless communication terminal , set a second EDCA parameter set timer based on whether a response to a MAC protocol data unit, MPDU, included in the trigger-based PPDU is received, when the second EDCA parameter set timer expires, terminate an application of the second EDCA parameter set, calculate a random integer value within a contention window, CW, set a backoff timer based on the random integer value, and access a channel based on the back off timer and a predetermined slot time, wherein each of the first and second EDCA parameter sets comprises a minimum value, CWmin, of the CW and a maximum value, CWmax, of the CW. transmit, to the base wireless communication terminal , a trigger-based physical layer protocol data unit, PPDU, using the transceiver , switch an enhanced distributed channel access, EDCA, parameter set, which is a set of parameters used for the channel access, from a first EDCA parameter set to a second EDCA parameter set based on whether the base wireless communication terminal triggers a multi-user uplink transmission participation of the wireless communication terminal , set a second EDCA parameter set timer based on whether a response to a MAC protocol data unit, MPDU, included in the trigger-based PPDU is received, when the second EDCA parameter set timer expires, terminate an application of the second EDCA parameter set, calculate a random integer value within a contention window, CW, set a backoff timer based on the random integer value, and access a channel based on the back off timer and a predetermined slot time, wherein each of the first and second EDCA parameter sets comprises a minimum value, CWmin, of the CW and a maximum value, CWmax, of the CW. <EOS>