Apparatus for channel access in WLAN system and operating method of the apparatus

1 . An operating method of an access point (AP) multi-link device (MLD), the operating method comprising:

based on at least one non-AP MLD and at least one single link device (SLD) attempting channel access through a first link of the AP MLD, identifying a contention window of the at least one non-AP MLD, based on a ratio of, with respect to the first link, an idle time of the at least one non-AP MLD to an idle time of the at least one SLD; and

transmitting a beacon frame comprising information about the contention window to the at least one non-AP MLD.

2 . The operating method of claim 1 , wherein the identifying the contention window comprises:

quantifying channel utilization of the first link;

quantifying a channel use time of the at least one non-AP MLD; and

estimating the idle time of the at least one non-AP MLD, based on the channel utilization and the channel use time.

3 . The operating method of claim 2 , wherein the identifying the contention window comprises estimating an idle time of the at least one SLD, based on an idle time of the AP MLD.

4 . The operating method of claim 1 , wherein the idle time of the at least one non-AP MLD is less than the idle time of the at least one SLD, and

wherein the first link comprises a non-simultaneous transmit and receive (NSTR) link.

5 . The operating method of claim 1 , further comprising identifying an updated contention window of the at least one non-AP MLD, based on a period of one of a multiple of a transmission period of the beacon frame.

6 . The operating method of claim 1 , wherein the information about the contention window is indicated by an enhanced distribution channel access (EDCA) parameter set of the beacon frame, and

wherein the EDCA parameter set comprises a quality of service (QoS) Info field and an Update EDCA Info field.

7 . The operating method of claim 6 , further comprising transmitting the beacon frame to the at least one SLD,

wherein the QoS Info field comprises information about a second contention window of the at least one SLD.

8 . The operating method of claim 7 , wherein the QoS Info field comprises an EDCA Parameter Set Update Counter subfield indicating 0.

9 . The operating method of claim 6 , further comprising identifying whether to update an EDCA parameter of the at least one non-AP MLD, based on the Update EDCA Info field,

wherein the Update EDCA Info field comprises the information about the contention window.

10 . The operating method of claim 1 , wherein the beacon frame further comprises a basic service set (BSS) load element indicating channel utilization information.

11 . An access point (AP) multi-link device (MLD) comprising:

a transceiver; and

a processor configured to:

based on at least one non-AP MLD and at least one single link device (SLD) attempting channel access through a first link of the AP MLD, identify a contention window of the at least one non-AP MLD, based on a ratio of, with respect to the first link, an idle time of the at least one non-AP MLD to an idle time of the at least one SLD; and

control the transceiver to transmit a beacon frame comprising information about the contention window to the at least one non-AP MLD.

12 . The AP MLD of claim 11 , wherein the processor is configured to:

quantify channel utilization of the first link,

quantify a channel use time of the at least one non-AP MLD, and

estimate the idle time of the at least one non-AP MLD, based on the channel utilization and the channel use time.

13 . The AP MLD of claim 11 , wherein the processor is further configured to estimate the idle time of the at least one SLD, based on an idle time of the AP MLD.

14 . The AP MLD of claim 11 , wherein the idle time of the at least one non-AP MLD is less than the idle time of the at least one SLD, and

wherein the first link comprises a non-simultaneous transmit and receive (NSTR) link.

15 . The AP MLD of claim 11 , wherein the processor is configured to identify an updated contention window of the at least one non-AP MLD, based on a period of one of a multiple of a transmission period of the beacon frame.

16 . The AP MLD of claim 11 , wherein the processor is configured to control the transceiver to transmit the beacon frame to the at least one SLD,

wherein the information about the contention window is indicated by an enhanced distribution channel access (EDCA) parameter set of the beacon frame,

wherein the EDCA parameter set comprises a quality of service (QoS) Info field and an Update EDCA Info field,

wherein the QoS Info field comprises information about a second contention window of the at least one SLD and an EDCA Parameter Set Update Counter subfield, and the EDCA Parameter Set Update Counter subfield is 0,

wherein whether to update an EDCA parameter of the at least one non-AP MLD is identified based on the Update EDCA Info field, and

wherein the Update EDCA Info field comprises the information about the contention window.