Abstract: The present invention discloses a channel access method, apparatus and system, which can avoid signals at adjacent frequency bands interfere with each other. The method includes: monitoring, by a station STA, a channel state of a channel, wherein the channel comprises at least two sub-channels; sending, when it is monitored that the channel is in an idle state, a request to send a frame to an access point AP via at least one sub-channel in the channel; and if an access response frame fed back by the AP is received and the access response frame comprises identification information and channel resource allocation information of the station, determining that channel access succeeds, wherein the identification information and the channel resource allocation information of the station are used for indicating a channel resource allocated to the station for data transmission by the AP.

Abstract: Embodiments of the present invention provide a method and a device for accessing a channel. The method includes: receiving a contention request frame transmitted by a first transmitting end device on M sub-carriers, where the M sub-carriers at least have two inconsecutive sub-carriers, and the contention request frame is modulated onto the M sub-carriers; according to the contention request frame, acquiring channel state information about the first transmitting end device respectively on the M sub-carriers, and determining channel state information about the first transmitting end device respectively on N sub-carriers, where the N sub-carriers are obtained by dividing all or a part of a system available frequency band, the N sub-carriers include the M sub-carriers, both N and M are positive integers, N>M and M>1; and performing allocation of a transmission sub-channel according to the channel state information about the first transmitting end device respectively on the N sub-carriers.