these cells that are not optimally configured to continuously improve the mobility parameters by fine tuning them until a desired result is obtained, hence improving the overall mobility performance. Detection of poor mobility performance is based on the long-term evaluation of certain mobility counters and KPIs. The operator can further specify how mobility robustness should be fine tuned by being able to configure trigger conditions and exit criteria for these triggers. Let's have a look at the types of handover failures, how they can be detected, and what actions can be taken for each of these failures. CHAPTER 2 SELF-ORGANIZING NETWORKS IN LTE DEPLOYMENT Late Handovers Late handovers often result in a radio link failure to the established connection even before a handover procedure is initiated on the source eNodeB side or the handover procedure is completed on the target eNodeB side. Often, in a late handover case, the UE tries to reestablish the radio links with the destination eNodeB upon radio link failure. A popular means to reduce or have a check on the late handover failures is to detect such RRC reestablishment messages sent across from the UE to the target eNodeB and send them across an RLF indicator to the original source eNodeB. There the source eNodeB will recognize this as a late handover and can appropriately adjust the cell individual offset (CIO) for that particular neighbor SO the percentage of late handovers is reduced for the cell pair. This mechanism is described in detail in Section 22.4.2 of TS 36.300-990. The RLF indicator message is described in Section 8.3.9 of TS 36.423-960. For cases where the source and destination cell pairs belong to the same eNodeB, there will not be any X2 messaging to pass on the RLF indicator. Instead, the MRO corrective action will be taken care of by the eNodeB internally. Figure 2-14 shows an example of how a late handover case is handled as part of the MRO solution. Cell belonging Cell belonging to eNodeB B to eNodeB A X2 AP X2 AP handover process initiat