A method for spatial reuse operation performed by a station, STA, in a wireless local area network, WLAN, system, wherein the STA is according to IEEE 802.11ax standard, the method comprising: receiving a WLAN frame according to a legacy IEEE 802.11 standard through a wireless medium; determining whether a received signal strength of the WLAN frame exceeds a second clear channel assessment, CCA, level; the method being characterized by further comprising: when the received signal strength of the WLAN frame is above the second CCA level, determining whether the received WLAN frame is from a basic service set, BSS, of the STA; determining the status of the wireless medium as busy, when the received WLAN frame is from the BSS, and when the received signal strength of the WLAN frame is above the second CCA level; and when the received WLAN frame is not from the BSS, determining whether the received signal strength exceeds a first CCA level and setting the status of the wireless medium as idle and transmitting a signal using the wireless medium, when the received WLAN frame is not from the BSS, and when the received signal strength of the WLAN frame is below the first CCA level, wherein the first CCA level is a CCA level according to the IEEE 802.11ax standard, wherein the second CCA level is a CCA level according to a legacy IEEE 802.11 standard, and wherein the first CCA level is higher than the second CCA level. receiving a WLAN frame according to a legacy IEEE 802.11 standard through a wireless medium; determining whether a received signal strength of the WLAN frame exceeds a second clear channel assessment, CCA, level; the method being characterized by further comprising: when the received signal strength of the WLAN frame is above the second CCA level, determining whether the received WLAN frame is from a basic service set, BSS, of the STA; determining the status of the wireless medium as busy, when the received WLAN frame is from the BSS, and when the received signal strength of the WLAN frame is above the second CCA level; and when the received WLAN frame is not from the BSS, determining whether the received signal strength exceeds a first CCA level and setting the status of the wireless medium as idle and transmitting a signal using the wireless medium, when the received WLAN frame is not from the BSS, and when the received signal strength of the WLAN frame is below the first CCA level, wherein the first CCA level is a CCA level according to the IEEE 802.11ax standard, wherein the second CCA level is a CCA level according to a legacy IEEE 802.11 standard, and wherein the first CCA level is higher than the second CCA level. when the received signal strength of the WLAN frame is above the second CCA level, determining whether the received WLAN frame is from a basic service set, BSS, of the STA; determining the status of the wireless medium as busy, when the received WLAN frame is from the BSS, and when the received signal strength of the WLAN frame is above the second CCA level; and when the received WLAN frame is not from the BSS, determining whether the received signal strength exceeds a first CCA level and setting the status of the wireless medium as idle and transmitting a signal using the wireless medium, when the received WLAN frame is not from the BSS, and when the received signal strength of the WLAN frame is below the first CCA level, wherein the first CCA level is a CCA level according to the IEEE 802.11ax standard, wherein the second CCA level is a CCA level according to a legacy IEEE 802.11 standard, and wherein the first CCA level is higher than the second CCA level. <EOS>