A kind of method and apparatus for improving the mobility problem caused by the narrow switching range in the borderline region between the virtual subdistrict that is constructed by Multiple Small Cell Sites are provided.Virtual subdistrict (VC) includes multiple distributed base stations (DBS), and the DBS of VC collaboratively communicates with one another.Intermediate distribution formula base station (I-DBS) is located in the region of the adjacent at least two VC overlappings in multiple VC, and belongs to different VC according to time division scheme.