One disclosure of the specification provides a method performed by UE. The method comprises the steps of: receiving a synchronization signal from a network; on the basis of the UE being connected to a base station via an NTN satellite, receiving, from the network, system information related to an NTN; transmitting a RACH to the network; receiving a RA response message from the network; receiving measurement information from the network, wherein the measurement information includes information regarding a measurement point in time for measurement by the UE; determining, on the basis of orbit information of a target satellite, a measurable point in time when an elevation angle of the target satellite exceeds a threshold value; on the basis of the measurement point in time being earlier than the measurable point in time, transmitting a failure message to the network; and carrying out measurement at the measurable point in time.