Method for accessing wireless medium in wireless local area network and wireless device using the same

A first wireless device using a method for accessing a wireless medium in a wireless local area network (LAN) system, the first wireless device comprising:

• a transceiver for transmitting and receiving a radio signal;
• and
• a processor operatively coupled to the transceiver, wherein the processor is configured for:
• receiving from a second wireless device operating an access point (AP) a packet including identification information related to a receiving device which solicits a response frame,
• wherein the identification information is included in a physical layer (PHY) header of the packet,
• wherein the packet includes a broadcast frame including duration information related to a first duration to defer access to the wireless medium;
• determining whether the first wireless device is the receiving device based on the identification information;
• and
• when the first wireless device is the receiving device based on the determination, setting a network allocation vector (NAV) during a second duration,
• wherein the second duration is related to a length of time that a transmission time required for transmitting the response frame is excluded from the first duration.