To reduce data amount of identification information used for multicast data communication managed by a core network.

A core network device notifies an access network device of identification information of each service for receiving downlink multicast data. The access network device receives the identification information notified by the core network device to capture a wireless channel for a service identified by the identification information. The core network device transmits multicast data in a receivable format based on the identification information to the access network device. The access network device receives the multicast data transmitted from the core network device based on the identification information and transmits the received multicast data to a terminal via the wireless channel.