LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Single site verification: Network tuning: Single site verification step ensures every single site can work normally. The main target of network tuning is to ensure the coverage, control interference and clear basic handover problems. Normally network tuning is based drive test. Network parameters optimization: In network parameter optimization step, the main target is to ensure the KPI performance by field test and KPI statistics analysis. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning The different colors are used to distinguish different test routes which are overlapping in the map. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Weak coverage: Weak coverage can also decrease the QoS of service, cause call drop sometimes. Cross coverage: If the RSRP of pilot signal is very low, it is possible that UE can not camp in the cell or UE can not trigger registration. Cross coverage can generate the phenomenon of an "island". Therefore, when a call is connected to the island-shaped area far away from the eNodeB but still served by the eNodeB, and the cells adjacent to this "island" are not set to the neighboring cells of this cell during setting of cell handover parameters, call drop may occur immediately once the UE leaves this "island". When neighboring cells of cross coverage cell are configured and the coverage of the “island” is small, call drop may occurs if the UE moves fast. UE doesn’t have enough time to finish the signaling exchange with eNodeB when UE goes out of the coverage of the “island”. Lack of dominant cell: As a result of lack of dominant cell, handover occurs frequently, thus reducing system efficiency and increasing possibility of call drop. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning The figure in the slide shows the RSRP distribution of the best cell. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning The figure in the slide shows the distribution of PCI for the best cell. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning The distribution of UE transmission power reflects the distribution of uplink interference and uplink path loss. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning It can be seen from the figure in the slide that the UE transmission power is lower than 10dBm in normal situations, and will rise dramatically over 10dBm only when there is an uplink interference or coverage area edge. In comparison, a macro cell is more likely to subject to uplink coverage restriction than a micro cell. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning As shown in Figure, Over coverage is caused by the cell whose PCI is 288. Over Coverage will interfere with other cells and increase the call drop probability. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning From the figure, the cell of PCI 54 is the serving cell Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning The handover is happened from PCI 54 cell to PCI 56 cell Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning 4 cells’RSRP is familiar ,they have the same coverage at this Conner. According to the Mode3 interference between PCI 56 cell and PCI 8 cell ,and also the complex geography environment of the Conner then lead to Ping-Pong handover. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning CellIndividualOffset is used in A3 event which the algorithm is Mn+Ofn+Ocn-Hys > Ms+Ofs+Ocs+Off . CellIndividualOffset is corresponded to Ocn. IntraFreqHoA3TimeToTrig means measurement time of event A3 ,the default value of it is 320ms Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Uplink and downlink are not completely separated, poor downlink channel quality not only affects the downlink signaling demodulation. For example, incorrect PDCCH demodulation affects the scheduling of uplink signaling, resulting in uplink signaling lost. The uplink signaling lost may not only be caused by poor uplink channel quality but also poor downlink channel quality or other causes. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning All the parameters can shown in GENEX Probe which is HUAWEI drive test software. IBLER is initial BLER. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning In the signaling trace result, UE sent several measurement reports to eNodeB, but didn’t receive the handover command from eNodeB. Then call drop happened. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning To confirm the problem, we can also check the neighboring cell configuration in eNodeB. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning In eNodeB side we can see that eNodeB received several MEASUREMENT REPORT and sent RRC CONNECTION RECONFIGURATION(handover command). What’s more, eNodeB sent HANDOVER REQUEST to the target eNodeB. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning In UE side we can see that UE sent several MEASUREMENT REPORT to eNodeB, but it didn’t receive RRC CONNECTION RECONFIGURATION(handover command) from eNodeB. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning We can see that the time duration is less than 1 seconds in which the RSRP in target cell is 1dB higher than RSRP in serving cell. And then RSRP in serving cell decrease very fast. So UE can not receive handover command due to bad downlink channel quality. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Mn is the measurement result of the neighboring cell. Ofn is the frequency-specific offset for the frequency of the neighboring cell. Ocn is the cell-specific offset (that is, CIO) for the neighboring cell. Ofs is the frequency-specific offset for the serving frequency. Ocs is the cell-specific offset for the serving cell. Hys is the hysteresis for event A3. Off is the offset for event A3. Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission LTE Network Tuning Confidential Information of Huawei. No Spreading Without Permission
