A method for data transmission, a base station using the same and a user equipment (UE) using the same are proposed. The present disclosure configures at a base station at least two user equipments into a UE group for aggregate transmission by sending a control message from the base station to the at least two user equipments. Next, the base station transmits aggregated data to the UE group containing a aggregated PDU format containing a unique group identifier. Next, the base station receives a response signal from the UE group based on whether the first transmission is received or not. The base station re-transmits the aggregated data to the UE group if the first transmission is not received. After all the aggregate transmission is complete, the base station de-configures the UE group from the aggregate transmission.