In one embodiment, an apparatus, a system or a network (1) sets a discovery period for a node (2B). The discovery period is a time period in which the node (2B) sends a signal (e.g., PSS, SSS, and CRS) necessary for cell detection and radio measurement performed by a user equipment (3A) before a cell (20B), controlled by the node (2B), is to be turned on in order to send a signal (e.g., data signal) for either or both of user data reception and transmission. It is achieved, for example, that the user equipment (3A) is able to detect the signal (e.g., PSS, SSS, and CRS) for cell detection and radio measurement in the discovery period by using legacy behavior of radio measurement.