Section: 4.3.1.3.3 Number of handover failures related with MRO
Content: This measurement provides the number of outgoing handover related events that fail related with MRO. Handover related events include normal successful handovers and all failure events by which a UE in RRC connected state changes its serving cell without following a normal handover. Different MRO failure cases are found in [12]. The measurement includes separate counters for the number of handover failures classified as “too early”, “too late” and “to wrong cell”. The measurement for the too late handover is split to subcounters indicating the threshold of the serving cell itself was not crossed and the threshold of the neighbour cell was not crossed in UE measurements before handover in case the handover is triggered by more than one threshold of the measurement report triggering events, the subcounters are only needed if more than one threshold of the measurement report triggering events is used and using single or multiple thresholds is vendor specific. CC The measurements of too early handovers, too late handovers and to wrong cell handovers are obtained respectively by accumulating the number of failure events related to handover which are identified by the eNB according to the definitions in TS 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [12]. Besides being added to the measurement of total too late handovers, each too late handover (identified by the eNB according to the definitions in TS 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [12]) is also added to the relevant subcounter indicating the threshold of the serving cell itself configured in the measurement report triggering events (see 36.331 [18]) was not crossed or the threshold of the neighbour cell configured in the measurement report triggering events was not crossed if more than one threshold triggering a measurement report is configured to the UEs for the involved neighbour relation and the following UE measurement results are available for both cells involved in the too late handover - rsrpResult of “measResultLastServCell” and - rsrpResult of the subject neighbour cell in “measResultNeighCells” in a) the “RLF report” IE in the received RRC message “UEInformationResponse” (see 36.331 [18]), in case both cells involved in the too late handover belong to the same eNB, or b) the “UE RLF Report Container” IE in the received X2 message “RLF Indication”, in case the cells involved in the too late handover belong to different eNBs. The uncrossed threshold (of the serving itself and the neighbour) is identified by comparing the UE measurement results above with the configured thresholds (adding the corresponding hysteresis, see 36.331 [18]) of the measurement report triggering events, - if the threshold of the serving cell itself was not crossed, the observed too late handover is then added to the subcounter (HO.OutFail.TooLateOwnNotCrossed) indicating the threshold of the serving cell was not crossed - if the threshold of the neighbor cell itself was not crossed, the observed too late handover is then added to the subcounter (HO.OutFail.TooLateNeighborNotCrossed) indicating the threshold of the neighbour cell was not crossed - if the thresholds of both the serving cell itself and the neighbour cell were not crossed, then this too late handover is added to both subcounters (HO.OutFail.TooLateOwnNotCrossed and HO.OutFail.TooLateNeighborNotCrossed) indicating the threshold of serving cell itself was not crossed and the threshold of the neighbour cell was not crossed - if no threshold was not crossed, then this handover is only added to the measurement of total too late handovers but not to the subcounter indicating the threshold of the serving cell itself was not crossed or the threshold of the neighbour cell was not crossed. If only one threshold triggring the measurement report is configured to the UEs for the involved neighbour relation or the UE measurements above are not available, the observed too late handover is only added to the measurement of total too late handovers but not to the subcounter indicating the threshold of the serving cell itself was not crossed or the threshold of the neighbour cell was not crossed. Each measurement is an integer value. The measurements are named HO.OutFail.TooEarly HO.OutFail.TooLate Which indicates the total number of too late handovers identified by the eNB according to the definitions in TS 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [12]. HO.OutFail.TooLateOwnNotCrossed Which indicates the number of too late handovers for which the threshold of the serving cell itself was not crossed. HO.OutFail.TooLateNeighborNotCrossed Which indicates the number of too late handovers for which the threshold of the neighbor cell was not crossed. HO.OutFail.ToWrongCell Which indicates the number of “handover to wrong cell” cases on the NR (NR AB in Annex A.13) towards the target cell (see 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [12]). It is up to the eNodeB to decide whether or not the HO parameters of this NR are problematic in the “handover to wrong cell” case. HO.OutFail.HwcReestablish Which indicates the number of “handover to wrong cell” cases on the NR (NR AC in Annex A.13) towards the cell with which the UE attempts to re-establish the radio link connection (see 36.300[ Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 ]  [12]). It is up to the eNodeB to decide whether or not the HO parameters of this NR are problematic in the “handover to wrong cell” case. EUtranRelation Valid for packet switched traffic EPS