Improved scanning method and apparatus in wireless lan system

A method of performing scanning at a station (STA) in a wireless local area network (WLAN) system, the method comprising:

• to an access point (AP) supporting a first channel width and a second channel width, transmitting a probe request frame in the first channel width or the second channel width;
• and
• receiving a probe response frame from the AP in response to the probe request frame,
• wherein, if the probe request frame is transmitted in the first channel width, the probe response frame is received in the first channel width, and
• wherein the probe request frame is transmitted in the second channel width, the probe response frame is received in the second channel width.

An access point (AP) apparatus for supporting scanning of a station (STA) in a wireless local area network (WLAN) system, the AP apparatus comprising:

• a transceiver;
• and
• a processor,
• wherein the AP apparatus supports a first channel width and a second channel width,
• wherein the processor is configured to receive a probe request frame from the STA using the transceiver in the first channel width or the second channel width and to transmit a probe response frame to the STA using the transceiver in response to the probe request frame,
• wherein, if the probe request frame is received in the first channel width, the probe response frame is transmitted in the first channel width, and
• wherein the probe request frame is received in the second channel width, the probe response frame is transmitted in the second channel width.

A station (STA) apparatus for performing scanning in a wireless local area network (WLAN) system, the STA apparatus comprising:

• a transceiver;
• and
• a processor,
• wherein the processor is configured to transmit, to an access point (AP) supporting a first channel width and a second channel width, a probe request frame using the transceiver in the first channel width or the second channel width and to receive a probe response frame from the AP using the transceiver in response to the probe request frame,
• wherein, if the probe request frame is transmitted in the first channel width, the probe response frame is received in the first channel width, and
• wherein the probe request frame is transmitted in the second channel width, the probe response frame is received n the second channel width.