Method and apparatus for transmitting frame in wireless lan

An AP(access point) transmitting a frame in a wireless LAN, comprising:

• a RF(radio frequency) unit being configured to transmit or receive radio signals;
• and
• a processor being operatively connected to the RF unit,
• wherein the processor is configured:
• to transmit a RTS(request to send) frame for medium protection to a first STA(station) group,
• to sequentially receive CTS(clear to send) frames from each of multiple STAs being included in a second STA set as a response to the RTS frame, and
• to respectively transmit each of multiple PPDUs (physical layer protocol data unit) to each of the multiple STAs through each of multiple subbands for each of the multiple STAs within an overlapping time resource, and
• wherein the second STA set is included in the first STA set.

A method for transmitting a frame in a wireless LAN, comprising:

• transmitting, by an AP(access point), a RTS(request to send) frame for medium protection to a first STA(station) group;
• receiving, by the AP, CTS(clear to send) frames from each of multiple STAs being included in a second STA set as a response to the RTS frame within an overlapping time resource and an overlapping frequency resource, wherein the second STA set is included in the first STA set;
• and
• respectively transmitting, by the AP, each of multiple PPDUs (physical layer protocol data unit) to each of the multiple STAs included in the first STA set through each of multiple subbands for each of the multiple STAs included in the first STA set within an overlapping time resource,
• wherein a RA(receiver address) field of the RTS frame comprises identification information respective to each of the multiple STAs included in the first STA set.

An AP(access point) transmitting a frame in a wireless LAN, comprising:

• a RF(radio frequency) unit being configured to transmit or receive radio signals;
• and
• a processor being operatively connected to the RF unit,
• wherein the processor is configured:
• to transmit a RTS(request to send) frame for medium protection to a first STA(station) group,
• to receive CTS(clear to send) frames from each of multiple STAs being included in a second STA set as a response to the RTS frame within an overlapping time resource and an overlapping frequency resource, and
• to respectively transmit each of multiple PPDUs (physical layer protocol data unit) to each of the multiple STAs included in the first STA set through each of multiple subbands for each of the multiple STAs included in the first STA set within an overlapping time resource,
• wherein a RA(receiver address) field of the RTS frame comprises identification information respective to each of the multiple STAs included in the first STA set, and
• wherein the second STA set is included in the first STA set.