A communication method performed by a user equipment in a mobile communication system that provides a multicast/broadcast service (MBS), includes receiving, from a base station, a radio resource control (RRC) Release message that causes the user equipment to transition to an RRC inactive state, the RRC Release message including configuration information used for reception of a multicast session in the RRC inactive state, checking whether the multicast session has been activated, and suspending execution of predetermined processing to start reception of the multicast session when the multicast session has not been activated.