A paging signal transmission method according to the present invention includes: notifying, from a radio base station (eNB) to a mobile station (UE), a discontinuous reception interval and a total number of the groups, the discontinuous reception interval representing an interval at which discontinuous reception of the paging signal (PCH) is performed; determining, at the mobile station (UE), a timing for receiving the paging signal on the basis of the notified discontinuous reception interval and the notified total number of the groups; receiving, at the mobile station (UE), the paging signal transmitted from the radio base station (eNB), at the determined timing; and performing, at the mobile station (UE), incoming call processing, when the received paging signal is a paging signal addressed to the mobile station (UE).