The present invention discloses a user equipment that communicates with a base station in a first communication system, includes a transmitter configured to transmit to the base station an indication to report a co-existence problem experienced by the user equipment and assistance information for a co-existence working mode in which the user equipment performs a first communication with the base station and performs a second communication with an apparatus in a second communication system; a receiver configured to receive from the base station configuration information that include information of a co-existence working mode allowed to be utilized by the user equipment and information that indicates whether the user equipment can deny an uplink transmission of the first communication system and a message; and a processor configured to configure the co-existence working mode according to the configuration information.