A communication method according to an embodiment comprises: generating, by a base station, authentication information to be used for authentication processing between a WLAN apparatus and a radio terminal; transmitting, by the base station, a WT ADDITION REQUEST to the WLAN apparatus on the Xw interface, wherein the WT ADDITION REQUEST includes the authentication information and a WLAN media access control (MAC) address of the radio terminal; receiving, by the WLAN apparatus, the WT ADDITION REQUEST from the base station on the Xw interface; transmitting, by the base station, an Radio Resource Control (RRC) message including information for deriving the authentication information, to the radio terminal; receiving, by the radio terminal, the RRC message from the base station; deriving, by the radio terminal, the authentication information based on the information included in the RRC message; and performing, by the radio terminal, the authentication processing by using the authentication information.