LTE Planning and Optimization

RF optimization and trouble shootingNetwork deployment phase, tuningAfter commercial launch, optimization, KPI target and trouble shooting

What can do by driver test analysisRF coverageRF qualityAir interface signal analysis, UuParameter setting, SC, neighbour list, power setting

ToolsData collection toolLog file analysis toolTogether with OSS trace, UETR, CTR, etc. for deep analysisDriver Test Workshop1RF Optimization and Trouble Shootingby driver test1RF related issues and reasons

Poor CoveragePoor CPICH RSCP and/or CPICH Ec/No, not suitable for a proper connectionBad Radio EnvironmentBest Server is Missing, Interference, Pilot PollutionPoor uplink coverage insufficient UE Tx powerCongestionNo more available radio resources, RBS reaches the maximum Power in DL.Poor dominance best cell changes too frequently resulting in too many SHO eventsDriver Test Workshop2Dropped and Blocked Call Analysis 2RF related issues and reasons, continued

Missing NeighboursBetter cell that is not declared as a neighbour Fast change of RF conditions e.g. turning a cornerNot RadioRadio conditions are good Equipment FaultTEMS Investigation/UE Blocking or Freezing and/or SW is crashingDriver Test Workshop3Dropped and Blocked Call Analysis 3RSCP & Ec/Io decreases before drop for both scanner and UE, check for coverage problemsBefore the drop, the Ec/Io (and RSCP) decreases for UE only, scanner shows no decrease, the following considerations are useful:Soft handover errors, Best server of UE is not the same as that of scannerMissing neighbors, UE camps on a new cell after the drop, the new cell is not in the neighbor list of previous cell.Can check: does the UE measure this neighbor?Driver Test Workshop4Dropped Call Analysis Steps 4Dominate cell, Are there too many and too fast changes of best server making difficult for UE to perform measurements and SHO in time

Check UE Tx power, increase to max before the dropping call while Ec/Io level remains good?Dropped due to uplink coverage limitation, If the Tx power increase is gradual and UE is far from site.UE may not very far from site if the increase is sudden, check the uplink load - If the uplink load is high, it may be caused by traffic(checking statistics), or site fault - If uplink load is not high, problem could be due to possible power control failure.

Driver Test Workshop5Dropped Call Analysis Steps, Cont. 5Signals before the dropped call shall be analyzed if the above checking can not find the reasons

If the dropped call is not RF related and the RF conditions at the location of the drop appear to be good, no further work is needed as part of the RF Optimization.

Recording the location of the drop for future analysis

Driver Test Workshop6Dropped Call Analysis Steps, Cont. 6Driver Test Workshop7Dropped call, Poor Coverage61888 (SC = 205)62096 (SC = 293)

RSCP=-127dBm Ec/No=-32dBDriver Test Workshop8Dropped, Bad Radio Environment

Driver Test Workshop9Dropped call, Missing neighbour61888 (SC = 205)62096 (SC = 293)

Cell 248Cell 464Driver Test Workshop10Dropped, Congestion

Driver Test Workshop11Dropped, Not Radio

Driver Test Workshop12Blocked call, Bad Radio condition49046 (SC = 387)48007 (SC = 451)

12Driver Test Workshop13Blocked call, missing neighbours

49046 (SC = 387)48007 (SC = 451)13Driver Test Workshop14Blocked, Resources Unavailable

14Driver Test Workshop15Blocked call, Equipment Fault (UE)49046 (SC = 387)48007 (SC = 451)

15Driver Test Workshop16Blocked, Not allowed PLMN

Driver Test Workshop17Blocked, Unanswered RRC requests