A mobile communication system according to an exemplary aspect of the invention is a mobile communication system which includes eNBs (Evolved Universal Terrestrial Radio Access Network (E-UTRAN) NodeBs) and a core network apparatus, wherein the core network apparatus is provided as a Network Time Protocol (NTP) server and supplies clocks to the eNBs which are NTP clients; and the core network apparatus includes: an acquisition unit for acquiring transmission link delay information between the core network apparatus and each of the eNBs by periodically performing synchronization processing to each of the eNBs; a determination unit for determining a time of transmission based on the transmission link delay information acquired by the acquisition unit; and a unit for copying Multimedia Broadcast Multicast Service (MBMS) data as many as the eNBs, adding time information determined by the determination unit to each of copied MBMS data and transmitting the MBMS data to each of the eNBs.