A small cell receives a dedicated synchronization signal Preamble sent through a first message by a user equipment UE in an idle state. The dedicated Preamble is allocated when the UE accesses a network for the first time. The small cell according to the dedicated Preamble queries whether a first signaling radio bearer SRB 1 and/or a second signaling radio bearer SRB2 of the UE are/is stored. If stored, the small cell replies in a second message to the UE that indication information that the SRB 1 and/or the SRB2 between the small cell and the UE do/does not need to be re-established or modified. An uplink radio resource control RRC message sent through a dedicated control channel DCCH by the UE is received.