FMessage Too early handover detection Figure 2-15. Too early handover case is handled as a part of the MRO solution CHAPTER 2 SELF-ORGANIZING NETWORKS IN LTE DEPLOYMENT Handover to Wrong Cell Handovers often result in a radio link failure for a UE immediately after being handed over to a target cell, followed by the UE trying to reestablish the radio link connection with a cell that was not involved in the handover procedure. For example, after a successful handover from the cell belonging to eNodeB A to a cell belonging to eNodeB B, RLF happens, and the UE attempts connection reestablishment in the cell belonging to eNodeB C (as shown in Figure 2-16). In this case, eNodeB C sends an RLF indicator message to eNB B, followed by eNodeB B sending across a handover report message to eNodeB A indicating handover to the wrong cell. This mechanism is described in Section 22.4.2 of TS 36.300-990. Cell belonging Cell belonging Cell belonging to eNB B to eNB C to eNB A X2 AP X2 AP X2 AP HO completion Connection re-establ ishment Radio link failure RRCtoX2RLFmessage detection RRCtoX2RLFMessage X2 AP RL Indicato X2 AP HC report X2APtoMRORLFMess HO to wrong cell Figure 2-16. How handover to the wrong cell is handled Note that the handover report message will be sent even if eNodeB B and eNodeB C are the same and RLF indication is internal to the eNodeB. Also, if handover fails during handover from a cell in eNodeB A and the UE attempts to reestablish the connection to a cell in eNodeB C, eNodeB C will then send an RLF indicator to eNodeB A. In handover to a wrong cell, eNodeB A should note both eNodeB C and eNodeB B as handovers to the wrong cell CT (correct target) and handover to the wrong cell WT (wrong target) and adjust the corresponding cell individual offsets accordingly to reduce the rate of handover to wrong cell failure. Figure 2-16 shows an example case of how handover to the wrong cell case is handled as a part of the MRO solution. CHAPTER 2 SELF-ORGANIZING NETWORKS IN LTE DEPLOYMENT Load Balancing Clear load bala