A method includes monitoring, based on a first reference signal (RS), a downlink control channel in a control resource set (coreset). The method further includes receiving a control command indicating that a group of one or more second RSs is transmitted by a base station in a direction in which listen-before-talk (LBT) was performed. in response to the group of the one or more second RSs does not comprise the first RS, the method includes stopping monitoring the downlink control channel in the coreset.