Active scanning method in wireless LAN system

1. A method by a station for performing active scanning, the method comprising:

transmitting, over a first channel width corresponding to multiple of a second channel width, a probe request frame; and

receiving, over the first channel width, a probe response frame corresponding to the probe request frame from an access point,

wherein the probe response frame includes information on a primary channel of the access point,

wherein the first channel width includes a plurality of channels, and each of channels has the second channel width, and wherein the first channel width is greater than the second channel width, and

wherein the information on the primary channel indicates which the second channel width is the primary channel among the plurality of channels included in the first channel width.

2. The method of claim 1 , wherein the information on the primary channel being information on location of the primary channel.

3. A method by an access point for responding to active scanning, the method comprising:

receiving, over a first channel width corresponding to multiple of a second channel width, a probe request frame; and

generating, over the first channel width, a probe response frame in response to the probe request frame,

wherein the probe response frame includes information on a primary channel of the access point,

wherein the first channel width includes a plurality of channels, and each of channels has the second channel width, and wherein the first channel width is greater than the second channel width, and

wherein the information on the primary channel indicates which the second channel width is the primary channel among the plurality of channels included in the first channel width.

4. The method of claim 3 , wherein the information on the primary channel being information on location of the primary channel.

5. A station for performing active scanning, the station comprising:

a transceiver; and

a processor,

wherein the processor is configured to:

transmit, using the transceiver, over a first channel width corresponding to multiple of a second channel width, a probe request frame; and

receive, using the transceiver, over the first channel width, a probe response frame corresponding to the probe request frame from an access point,

wherein the probe response frames include information on a primary channel of the access point,

wherein the first channel width includes a plurality of channels, and each of channels has the second channel width, and wherein the first channel width is greater than the second channel width, and

wherein the information on the primary channel indicates which the second channel width is the primary channel among the plurality of channels included in the first channel width.

6. An access point for responding to active scanning, the access point comprising:

a transceiver; and

a processor,

wherein the processor is configured to:

receive, using the transceiver, over a first channel width corresponding to multiple of a second channel width, a probe request frame; and

generate, using the transceiver, over the first channel width, a probe response frame in response to the probe request frame,

wherein the probe response frame includes information on a primary channel of the access point,

wherein the first channel width includes a plurality of channels, and each of channels has the second channel width, and wherein the first channel width is greater than the second channel width, and

wherein the information on the primary channel indicates which the second channel width is the primary channel among the plurality of channels included in the first channel width.