ease of the RRC connections is initiated by the E-UTRAN. The procedure may be used to redirect the UE to another frequency or Radio Access Technology (RAT). In certain cases, the UE may discontinue RRC connection, i.e., it may move to RRC_IDLE without notifying the E-UTRAN. In RRC_CONNECTED, the network controls UE mobility, i.e., the network decides when the UE must move to another cell, which may be on another frequency or RAT. For network controlled mobility in the RRC_CONNECTED state, handover is the only procedure that is defined. The network triggers the handover procedure, based on radio conditions or load. The network may configure the UE to perform measurement reporting including the configuration of measurement gaps. The network may also initiate handover without having received measurement reports from the UE. Before sending the handover message to the UE, the source eNB prepares one or more target cells. The target eNB generates the message used to perform the handover, including the AS-configuration to be used in the target cell. The source eNB transparently forwards the handover message/information received from the target to the UE. The source eNB may initiate data forwarding for some of the user data RBs. After receiving the handover message, the UE attempts to access the target cell at the first available Random Access Channel (RACH) opportunity according to random access resource selection procedure for asynchronous handover. When allocating a dedicated preamble for random access in the target cell, the E-UTRA ensures it is available from the first RACH opportunity the UE may utilize. On successful completion of the handover, the UE sends a message to confirm the handover. Following successful completion of handover, the PDCP SDUs may be re-transmitted in the target cell. This only applies for user data RBs using RLC-AM mode. Furthermore, the Sequence Number (SN) and the Hyper-Frame Number (HFN) are reset, except for user data RBs using RLC-AM mode for which both SN and HFN may continue. For a l