a base station , includes : a transmitter , configured to transmit a first coexistent interference frequency set configured for ue to a target base station , when the ue is handed over from a source base station to the target base station ; wherein coexistence interference on each frequency in the first coexistence interference frequency set is to be evaluated by the ue when the ue is in a cell of the source base station , and the evaluation results indicate that whether there exists coexistent interference on each frequency in the first coexistent interference frequency set .