A method and a user equipment (UE) for network attachment are disclosed. The method includes receiving first status information associated with one or more remote radio units (RRUs) for supporting the small cell from the one or more RRUs, receiving second status information associated with one or more macro cells from one or more macro eNBs for supporting the macro cell, selecting an RRU and macro eNB, which the UE wants to attach, among the one or RRUs based on the first status information and the second status information, and simultaneously transmitting an attach request message for requesting network attachment from the selected RRU and macro eNB to the selected RRU and macro eNB.