Method and device for controlling service period of target wake time in wireless LAN system

1 . A method comprising:

receiving, by a station (STA) from an access point (AP), first information related to restricted target wake time (r-TWT);

receiving, by the STA from the AP, second information related to an extension of an end time of a service period (SP) of the r-TWT; and

transmitting, by the STA to the AP, third information related to whether to maintain an awake state until the end time of the extended SP,

wherein based on the third information indicating that the awake state is maintained until the end time of the extended SP, a power save (PS)-poll frame querying at least one of i) presence or absence of additional data to be received from the AP until the end time of the extended SP or ii) a size of the additional data is transmitted from the STA to the AP.

2 . The method of claim 1 , wherein:

a minimum duration in which the STA must remain awake is updated as a duration between a time at which data starts to be transmitted from the AP within the SP and the end time of the extended SP.

3 . The method of claim 1 , wherein:

the second information includes information related to extending the end time, and

the information related to extending the end time is indicated by at least one of a specific value of a more data subfield, an end of service period (EOSP) subfield, or a TWT setup command subfield.

4 . The method of claim 1 , wherein:

the second information is indicated by a field set to indicate whether to extend the end time.

5 . The method of claim 1 , wherein:

the second information corresponds to an action field of a TWT setup frame including a broadcast TWT identification (ID) identifying the r-TWT.

6 . The method of claim 1 , wherein:

the third information is indicated by a power management subfield of a frame control field.

7 . The method of claim 1 , wherein:

based on information indicating the presence of additional data to be received from the AP being received, until the end time of the extended SP, the awake state is maintained and the additional data is received from the AP.

8 . The method of claim 1 , wherein:

based on the third information indicating that the awake state is not maintained until the end time of the extended SP, after an initial end time of the SP of the r-TWT set based on the first information, the awake state is converted to a doze state.

9 . A station (STA) comprising:

at least one transceiver; and

at least one processor connected to the at least one transceiver,

wherein the at least one processor is configured to:

receive, from an access point (AP) through the at least one transceiver, first information related to restricted target wake time (r-TWT);

receive, from the AP through the at least one transceiver, second information related to an extension of an end time of a service period (SP) of the r-TWT; and

transmit, to the AP through the at least one transceiver, third information related to whether to maintain an awake state until the end time of the extended SP,

wherein based on the third information indicating that the awake state is maintained until the end time of the extended SP, a power save (PS)-poll frame querying at least one of i) presence or absence of additional data to be received from the AP until the end time of the extended SP or ii) a size of the additional data is transmitted from the STA to the AP.

10 . An access point (AP) comprising:

at least one transceiver; and

at least one processor connected to the at least one transceiver,

wherein the at least one processor is configured to:

transmit, to a station (STA) through the at least one transceiver, first information related to restricted target wake time (r-TWT);

transmit, to the STA through the at least one transceiver, second information related to an extension of an end time of a service period (SP) of the r-TWT; and

receive, from the STA through the at least one transceiver, third information related to whether to maintain an awake state until the end time of the extended SP,

wherein based on the third information indicating that the awake state is maintained until the end time of the extended SP, a power save (PS)-poll frame querying at least one of i) presence or absence of additional data to be transmitted to the STA until the end time of the extended SP or ii) a size of the additional data is received by the AP from the STA.