The present specification provides a method and an apparatus therefor, in which, in a method for performing an integrated access and backhaul (JAB) operation performed by a node in a wireless communication system, an initial access operation is performed with another node, information about a capability supported by the node is transmitted to the other node, wherein the information about the capability is information informing about at least one timing alignment case supported by the node among a plurality of timing alignment cases, and the IAB operation is performed on the basis of the at least one timing alignment case.