Abstract: A method for reporting idle measurement report for secondary cell addition is provided. The method includes: receiving, by a UE during a connection release, an idle measurement configuration indicating a set of neighboring frequencies distinct from a serving frequency; performing, by the UE, an idle measurement with each frequency of the set of neighboring frequencies; reselecting, by the UE, a new serving frequency for a new serving cell; receiving, by the UE, a request to provide an idle measurement report when the UE moves to a connected mode with the new serving cell on the new serving frequency; performing, by the UE based on a CA compatibility, a filtering operation on the set of neighboring frequencies to identify frequencies that are compatible with the new serving frequency; and sending, by the UE, the idle measurement report indicating the frequencies that are compatible with the new serving frequency.