Disclosed is a sensing apparatus for sensing movement by using a measurement value, which represents a channel state, measured using a WLAN signal. The sensing apparatus comprises a memory; and a processor. The processor obtains a standard deviation of the magnitude of the measurement value during a predetermined number of measurements or within a predetermined time interval, and obtains a characteristic value of a sensing algorithm on the basis of the obtained standard deviation, and the sensing algorithm is an algorithm trained on the basis of a correlation between a value obtained on the basis of the magnitude of the measurement value and whether or not movement occurs around devices exchanging the wireless LAN signal.

Disclosed is a server for receiving information detected from an access point (AP) detecting movement by using a wireless LAN signal. The server comprise a memory and a processor. The processor receives, from the AP, an identifier of a basic service set (BSS) operated by the AP, receives, from a user application, an identifier of a BSS coupled with a station in which the user application operates, pairs the AP and the user of the user application if the identifier of the BSS received from the AP is the same as the identifier received from the user application, and transmits, to the user application, information about the result of detecting the movement received from the AP.

The method comprises the steps of receiving channel information from a first access point (AP) through a network (wherein the channel information includes a link metric measured on the basis of a communication signal with a second AP, and the first AP is provided in a first subway cabin and the second AP is provided in a second subway cabin that is adjacent to the first subway cabin); calculating the congestion level of the first subway cabin or the second subway cabin on the basis of the received channel information (wherein the congestion level indicates the level related to the number of passengers present in the subway cabin); and providing the calculated congestion level of the subway cabin to a user terminal.

A method for client steering in a multiple access point (AP) network is performed by a controller and comprises the steps of receiving, from one or more APs, pieces of related information for the client steering; on the basis of the pieces of information, determining a particular candidate BSS for the client steering from among a plurality of BSSs; and transmitting a request message for the client steering to an AP operating the particular candidate BSS.