The present disclosure provides a method for data transmission or reception performed by a first node in a wireless communication system, the method including: performing a first data transmission or reception to or from a UE on an access link on the basis of a first timing case in an access time duration; and performing a second data transmission or reception to or from a second node or a donor base station on a backhaul link on the basis of a second timing case in a backhaul time duration, wherein downlink transmission timings over the donor base station, the first node, the second node and the UE are aligned in the first timing case, and downlink and uplink transmission timings or downlink and uplink reception timings are aligned in the first node in the second timing case.