Method and device for configuring spatial reuse field in wireless LAN system

1. A method in a wireless local area network (WLAN) system, the method comprising:

receiving, by a receiving station (STA), a trigger frame from a transmitting STA; and

transmitting, by the receiving STA, a Trigger Based Physical Protocol Data Unit (TB PPDU) through a preset frequency band to the transmitting STA,

wherein the trigger frame includes a common information field and a special user information field,

wherein the common information field includes first to fourth spatial reuse fields,

wherein the special user information field includes fifth and sixth spatial reuse fields,

wherein when the preset frequency band is a 20 MHz band, the first to fourth spatial reuse fields are set to a value of the fifth spatial reuse field,

wherein when the preset frequency band is a 40 MHz band, the first and third spatial reuse fields are set to a value of the fifth spatial reuse field, and the second and fourth spatial reuse fields are set to a value of the sixth spatial reuse field,

wherein when the preset frequency band is an 80 MHz band, the first and second spatial reuse fields are set to a value of the fifth spatial reuse field, and the third and fourth spatial reuse fields are set to a value of the sixth spatial reuse field,

wherein when the preset frequency band is a 160 MHz band, the first and second spatial reuse fields are set to a value of the fifth spatial reuse field, and the third and fourth spatial reuse fields are set to a value of the sixth spatial reuse field, and

wherein when the preset frequency band is a 320 MHz band, the first to fourth spatial reuse fields are set to a smaller value among the values of the fifth and sixth spatial reuse fields.

2. The method of claim 1 , wherein when the preset frequency band is the 20 MHz band, the values of the first to fourth spatial reuse fields are spatial reuse values for the 20 MHz band.

3. The method of claim 1 , wherein when the preset frequency band is the MHz band, the values of the first and third spatial reuse fields are spatial reuse values for a first 20 MHz subchannel having a low frequency in the 40 MHz band, and the values of the second and fourth spatial reuse fields are spatial reuse values for a second 20 MHz subchannel having a high frequency in the 40 MHz band.

4. The method of claim 3 , wherein when the TB PPDU is transmitted in a 2.4 GHz band, the spatial reuse value for the second 20 MHz subchannel is set equal to the spatial reuse value for the first 20 MHz subchannel,

wherein the spatial reuse value for the first 20 MHz subchannel is a value used to calculate transmit power accessible by an Overlapping Basic Service Set (OBSS) High Efficiency (HE) STA for the first 20 MHz subchannel,

wherein the spatial reuse value for the second 20 MHz subchannel is a value used to calculate transmit power accessible by the OBSS HE STA for the second 20 MHz subchannel.

5. The method of claim 1 , wherein when the preset frequency band is the MHz band, the value of the first spatial reuse field is a spatial reuse value for the lowest first 20 MHz subchannel in the 80 MHz band, the value of the second spatial reuse field is a spatial reuse value for a second 20 MHz subchannel that is second lowest in the 80 MHz band, the value of the third spatial reuse field is a spatial reuse value for a third 20 MHz subchannel that is second highest in the 80 MHz band, and the value of the fourth spatial reuse field is a spatial reuse value for the fourth 20 MHz subchannel that is the highest in the MHz band.

6. The method of claim 1 , wherein when the preset frequency band is the 160 MHz band, the value of the first spatial reuse field is a spatial reuse value for the lowest first 40 MHz subchannel in the 160 MHz band, the value of the second spatial reuse field is a spatial reuse value for a second 40 MHz subchannel that is second lowest in the 160 MHz band, the value of the third spatial reuse field is a spatial reuse value for a third 40 MHz subchannel that is second highest in the 160 MHz band, and the value of the fourth spatial reuse field is a spatial reuse value for the fourth 40 MHz subchannel that is the highest in the 160 MHz band.

7. The method of claim 1 , wherein when the preset frequency band is the 320 MHz band, the value of the first spatial reuse field is a spatial reuse value representing a first 40 MHz subchannel having the lowest frequency within each 160 MHz channel of the 320 MHz band, the value of the second spatial reuse field is a spatial reuse value representing a second 40 MHz subchannel having a second lowest frequency within each 160 MHz channel of the 320 MHz band, the value of the third spatial reuse field is a spatial reuse value representing a third 40 MHz subchannel having a second highest frequency within each 160 MHz channel of the 320 MHz band, and the value of the fourth spatial reuse field is a spatial reuse value representing a fourth 40 MHz subchannel having the highest frequency within each 160 MHz channel of the 320 MHz band.

8. The method of claim 1 , wherein the common information field includes a first bandwidth field, and the special user information field includes a second bandwidth field;

wherein a bandwidth of the preset frequency band is set based on the first and second bandwidth fields.

9. The method of claim 1 , wherein the TB PPDU includes a Universal-Signal (U-SIG) field,

wherein the U-SIG field includes seventh and eighth spatial reuse fields,

wherein the seventh spatial reuse field is configured by duplicating the fifth spatial reuse field,

wherein the eighth spatial reuse field is configured by duplicating the sixth spatial reuse field.

10. The method of claim 9 , wherein values of the seventh and eighth spatial reuse fields are normalized values for each 20 MHz subchannel.

11. A receiving station (STA) in a wireless local area network (WLAN) system, the receiving STA comprising:

a memory;

a transceiver; and

a processor being operatively connected to the memory and the transceiver,

wherein the processor is configured to:

receive a trigger frame from a transmitting STA; and

transmit a Trigger Based Physical Protocol Data Unit (TB PPDU) through a preset frequency band to the transmitting STA,

wherein the trigger frame includes a common information field and a special user information field,

wherein the common information field includes first to fourth spatial reuse fields,

wherein the special user information field includes fifth and sixth spatial reuse fields,

wherein when the preset frequency band is a 20 MHz band, the first to fourth spatial reuse fields are set to a value of the fifth spatial reuse field,

wherein when the preset frequency band is a 40 MHz band, the first and third spatial reuse fields are set to a value of the fifth spatial reuse field, and the second and fourth spatial reuse fields are set to a value of the sixth spatial reuse field,

wherein when the preset frequency band is an 80 MHz band, the first and second spatial reuse fields are set to a value of the fifth spatial reuse field, and the third and fourth spatial reuse fields are set to a value of the sixth spatial reuse field,

wherein when the preset frequency band is a 160 MHz band, the first and second spatial reuse fields are set to a value of the fifth spatial reuse field, and the third and fourth spatial reuse fields are set to a value of the sixth spatial reuse field, and

wherein when the preset frequency band is a 320 MHz band, the first to fourth spatial reuse fields are set to a smaller value among the values of the fifth and sixth spatial reuse fields.

12. A method in a wireless local area network (WLAN) system, the method comprising:

transmitting, by a transmitting station (STA), a trigger frame to a receiving STA; and

receiving, by the transmitting STA, a Trigger Based Physical Protocol Data Unit (TB PPDU) from the receiving STA through a preset frequency band,

wherein the trigger frame includes a common information field and a special user information field,

wherein the common information field includes first to fourth spatial reuse fields,

wherein the special user information field includes fifth and sixth spatial reuse fields,

wherein when the preset frequency band is a 20 MHz band, the first to fourth spatial reuse fields are set to a value of the fifth spatial reuse field,

wherein when the preset frequency band is a 40 MHz band, the first and third spatial reuse fields are set to a value of the fifth spatial reuse field, and the second and fourth spatial reuse fields are set to a value of the sixth spatial reuse field,

wherein when the preset frequency band is an 80 MHz band, the first and second spatial reuse fields are set to a value of the fifth spatial reuse field, and the third and fourth spatial reuse fields are set to a value of the sixth spatial reuse field,

wherein when the preset frequency band is a 160 MHz band, the first and second spatial reuse fields are set to a value of the fifth spatial reuse field, and the third and fourth spatial reuse fields are set to a value of the sixth spatial reuse field, and

wherein when the preset frequency band is a 320 MHz band, the first to fourth spatial reuse fields are set to a smaller value among the values of the fifth and sixth spatial reuse fields.

13. The method of claim 12 , wherein when the preset frequency band is the MHz band, the values of the first to fourth spatial reuse fields are spatial reuse values for the 20 MHz band.

14. The method of claim 12 , wherein when the preset frequency band is the MHz band, the values of the first and third spatial reuse fields are spatial reuse values for a first 20 MHz subchannel having a low frequency in the 40 MHz band, and the values of the second and fourth spatial reuse fields are spatial reuse values for a second 20 MHz subchannel having a high frequency in the 40 MHz band.

15. The method of claim 12 , wherein when the preset frequency band is the MHz band, the value of the first spatial reuse field is a spatial reuse value for the lowest first 20 MHz subchannel in the 80 MHz band, the value of the second spatial reuse field is a spatial reuse value for a second 20 MHz subchannel that is second lowest in the 80 MHz band, the value of the third spatial reuse field is a spatial reuse value for a third 20 MHz subchannel that is second highest in the 80 MHz band, and the value of the fourth spatial reuse field is a spatial reuse value for the fourth 20 MHz subchannel that is the highest in the 80 MHz band.