Method for transmitting data in wireless communication system and apparatus therefor
A method for performing, by a station (STA) apparatus, uplink (UL) multi-user (MU) transmission in a wireless communication system according to an embodiment of the present invention includes performing carrier sensing on a channel, receiving a trigger frame including information for UL MU transmission and a carrier sense indicator indicating whether a result of the carrier sensing is to be reflected from an access point (AP), and transmitting an UL MU frame through the channel based on the information for UL MU transmission. The UL MU frame is transmitted through the channel based on a result of the carrier sensing if the carrier sense indicator indicates the reflection of a result of the carrier sensing. The UL MU frame is transmitted through the channel regardless of a result of the carries sensing if the carrier sense indicator does not indicate the reflection of a result of the carrier sensing.
1. A method for receiving, by a access point (AP) apparatus, uplink (UL) multi-user (MU) transmission in a wireless communication system, the method comprising:
transmitting a trigger frame including information for the UL MU transmission and an indicator indicating whether or not to execute carrier sensing; and
receiving a UL MU frame in response to the trigger frame,
wherein the UL MU frame is transmitted based on a result of the carrier sensing on the specific channel executed by a station(STA), when the indicator indicates the carrier sensing, and is transmitted without the carrier sensing when the indicator indicated not executing the carrier sensing;
wherein the UL MU frame is transmitted through the specific channel, when the specific channel is considered idle as a result of considering both a channel clear assessment (CCA) and a network allocation vector (NAV) and is not transmitted through the specific channel, when the specific channel is considered busy as the result of considering both the CCA and the NAV,
wherein the NAV indicates idle when the NAV count value is nonzero but a non-bandwidth signaling transmitter address (TA) of the trigger frame is same as an address of a transmission opportunity(TXOP) holder, and
wherein the CCA indicates idle when a detected energy level through energy detection does not exceed a threshold and the CCA indicates busy when the detected energy level through the energy detection exceeds the threshold.
2. The method of claim 1 , wherein the carrier sensing is executed by performing energy detection to check CCA during a short interframe space (SIFS) after receiving the trigger frame.
3. The method of claim 1 , wherein the specific channel corresponds to a channel allocated to the STA.
4. The method of claim 1 , wherein the specific channel is considered idle when both the CCA and the NAV indicate idle, and wherein the specific channel is considered busy when at least one of the CCA or the NAV indicates busy.
5. The method of claim 4 , wherein the NAV indicates idle when a NAV count value is zero.
6. The method of claim 1 ,
wherein the UL MU frame is transmitted without considering the NAV, when the AP transmitting the trigger frame is a transmission opportunity (TXOP) holder setting the NAV of the STA.
7. The method of claim 6 , wherein the carrier sensing is executed by performing energy detection to check CCA during a short interframe space (SIFS) after receiving the trigger frame.
8. The method of claim 6 , wherein the specific channel corresponds to a channel allocated to the STA.
9. The method of claim 8 , wherein the NAV indicates idle when a NAV count value is zero.
10. The method of claim 6 ,
wherein the specific channel is considered idle when both the CCA and the NAV indicate idle, and
wherein the specific channel is considered busy when at least one of the CCA or the NAV indicates busy.
11. The method of claim 6 ,
wherein the UL MU frame is transmitted without considering the NAV, when the AP transmitting the trigger frame is a transmission opportunity (TXOP) holder setting the NAV of the STA.
12. An access point(AP) performing uplink (UL) multi-user (MU) reception in a wireless communication system, the AP comprising:
a radio frequency(RF) unit configured to transmit/receive radio signals; and
a processor configured to control the RF unit,
wherein the processor is configured to:
transmit a trigger frame including information for the UL MU transmission and an indicator indicating whether or not to execute carrier sensing, and
receive a UL MU frame in response to the trigger frame,
wherein the UL MU frame is transmitted based on a result of the carrier sensing on the specific channel executed by a station(STA), when the indicator indicates the carrier sensing, and is transmitted without the carrier sensing when the indicator indicated not executing the carrier sensing;
wherein the UL MU frame is transmitted through the specific channel, when the specific channel is considered idle as a result of considering both a channel clear assessment (CCA) and a network allocation vector (NAV) and is not transmitted through the specific channel, when the specific channel is considered busy as the result of considering both the CCA and the NAV,
wherein the NAV indicates idle when the NAV count value is nonzero but a non-bandwidth signaling transmitter address (TA) of the trigger frame is same as an address of a transmission opportunity(TXOP) holder, and
wherein the CCA indicates idle when a detected energy level through energy detection does not exceed a threshold and the CCA indicates busy when the detected energy level through the energy detection exceeds the threshold.