Guideline

L1 Training EngineerDRIVE TEST ANALYSTConfidential L1 Training EngineerDrive Test AnalystSection 42G LOG FILES ANALYSIS Confidential Undecoded BCCHBSIC Undecode in Other SiteNo HandoverDelay HandoverPing Pong HandoverNegative HandoverOvershootingHigh OverlappingNo Dominant ServerPoor CoverageUnreasonable Serving AreaInterferenceHandover FailureHandover LossUL DropDrop CallSudden Power DropMS Power Rapid Increase

Below lists common problems which can be observed from Drive Test Log.TEMS .log file AnalysisConfidential 3Undecoded BCCHDescription:BSICs cant be decoded in 5sUsually consider 3 strongest neighborsReason:BTS clock shift, only decode same site BSICsHardware FaultyChannel interferenceNon-BCCH carrier, no dedicated spectrum for BCCH

Confidential 4Undecoded BCCH

Confidential 5BSIC Undecode in Other SiteDescription:BSIC in same site can be decoded but not for other sitesHandover can only happen in intra-site basisIt is similar to former Undecoded BCCH caseReason:BTS clocking shiftedHardware FaultyNo one monitors OMC-R alarmsConfidential 6No HandoverDescription:Neighbor BSIC is decoded and COMMON handover requirement is fulfilled but there is never a handoverReason:Missing neighborNo such neighbor in databaseIncorrect external neighborTarget cells LAC/BCCH/BSIC in add neighbor is different from realityServing cell overshoots/covers too far away

Confidential 7No Handover

Confidential 8Delay HandoverDescription:Neighbor BSIC is decoded but handover occurs in much later timeReason:All possible neighbors suffer blockingLarge averaging period settingLarge handover margin settingConfidential 9Delay Handover

Confidential 10Ping Pong HandoverDescription:Lot of handovers between cellsReason:Hardware faultUL/DL interferenceNegative handoverDifferent coverage footprint for antennas of a cell

Confidential 11Ping Pong Handover

Confidential 12Negative HandoverDescription:Serving cell hands over to a weaker neighborReason:Adjacencies parameter wrong settingConfidential 13Negative Handover

-59dBm before HO-66dBm after HOConfidential 14OvershootingDescription:Cell shoots at far distance but that location has closer cells aroundReason:Overshooting cell has small downtilt, 0 degree!Overshooting cell has too high altitudeCloser cells have overshooting as wellBSIC of closer cells cant be decodedConfidential 15Overshooting

Confidential 16High OverlappingDescription:Cells have major rxlevel difference within 5dBReason:OvershootingToo many cells in that areaPoor antenna downtiltConfidential 17High Overlapping

Over Lapping Area-65dBm-65dBm-65dBm-65dBmConfidential 18No Dominant ServerDescription:Rxlevel of best neighbors are close to that of serving cellReason:Poor antenna downtiltLack of near-by siteConfidential 19No Dominant Server

Confidential 20Poor CoverageDescription:Low rxlevel with rxqualityIn rural area, rxlevel is less than 15 (-95dBm)In city center, rxlevel is less than 35 (-85dBm)Different location has different threshold, noise level is the key pointReason:Lack of cell siteBSIC of dominant server cant be decodedDominant server has blocking or cell-barHandover problem. E.g. missing & incorrect neighbor, negative handover, no & delay handoverConfidential 21Poor Coverage

Confidential 22Unreasonable Serving AreaDescription:Coverage area of the cell is incoherent to the antenna directionReason:Wrong cable connection to antennasIncorrect record of antenna orientationCross Feeder of Antenna lines

Confidential 23InterferenceDescription:High rxlevel with low qualityReason:Channel interferenceNot using dominant serverNo handoverTurn the corner with delay handoverConfidential 24Interference

Confidential 25Handover FailureDescription:MS fails to reach target cell, so return to source cellMS sends HO FAILURE and UL-SABM to source cell and there is responseReason:Channel interferencePoor coverageExternal interference at UL, like wideband repeatorConfidential 26Handover Failure

Confidential 27Handover LossDescription:MS fails to reach target cell, but cant return to source cellMS sends HO FAILURE and UL-SABM to source cell but no responseReason:Channel interferencePoor coverageExternal interference at UL, like wideband repeatorConfidential 28Handover Loss

Confidential 29Description:BSS doesnt receive UL SACCH for link fail timesBSS stops transmitting DL powerReason:External interferenceChannel interferenceFaulty ancillary. UL path loss >>> DL path lossCross feeder in antenna line (partial cross feeder)UL Drop Confidential 30UL Drop

Confidential 31Drop CallDescription:DL case: Radio_link_timeout counter decreases to 0UL case: link_fail counter decreases to 0Reason:All cases in this presentationConfidential 32Drop Call

Confidential 33Sudden Power DropDescription:Dedicated ARFCN has significant rxlevel difference from rxlevel of BCCHReason:Cross feeder in antenna lines (partial crossfeeder)Faulty ancillary. E.g. TRX power, combiner, filter..UL and DL has different path loss due to crossfeederDue to air combining, so antennas have different coverage footprints; different alignment between 2 antennaTurn around the cornerConfidential 34Sudden Power Drop

Confidential 35MS Power Rapid Increase

UL power rapid increase from 19 to 5 suddenlyConfidential 36

Section 4.ASAMPLES OF 2G DT OPTIMIZATIONL1 Training EngineerDT Analyst

Section 42G LOG FILE ANALYSISConfidential Page 37Page 37HANDOVER DELAYED (1)

Problem Description: Late handover causing bad SQIServing Cells: GDGPROMOTORMD2 and GDGPROMOTORMD1Recommendation: Make faster handover from GDGPROMOTORMD2 to GDGPROMOTORMD1 and increase POC step sizeLog File: Sutirak_0512_13.log33. Jl. Sultan Iskandar Muda NS (Open)Confidential HANDOVER DELAYED (1)

Problem Description: SQI performance improvedServing Cells: GDGPROMOTORMD2 and GDGPROMOTORMD1Recommendation: Performance monitoringLog File: Faze_0616_09.log33. Jl. Sultan Iskandar Muda NS (Closed)Confidential HANDOVER DELAYED (2)

Problem Description: PANINOD2 Dragging call with bad SQIServing Cells: PANINOD2, PANINOD1, PANINMG/MD1Recommendation: Re-define HO parameter and make faster HO to PANINOD1 Log File: 1221_06.log4. Jl. Jend. Sudirman (NS)Confidential HANDOVER DELAYED (2)

Problem Description: PANINOD2 Dragging call with bad SQI solved faster HO between PANINOD1 & OD2Serving Cells: PANINOD2, PANINOD1, PANINMG/MD1Recommendation: Performance MonitoringLog File: 0305_02.log4. Jl. Jend. Sudirman (NS) - ClosedConfidential HANDOVER DELAYED (3)

Problem Description: Delay handover to HILTONOD2 and RATUPLZOD1dragging the callServing Cells: GRAHANIAGAOD1 and HILTONOD2Recommendation: Make faster HO to HILTONOD2 and make faster HO from RATUPLZOD1 to GRAHANIAGAOD2Log File: 0407_03.log4. Jl. Jend. Sudirman (NN) (OPEN)Confidential HANDOVER DELAYED (3)

Problem Description: SQI and handover improved after changing HO parameter on RATUPLZODServing Cells: GRAHANIAGAOD1 and HILTONOD2Recommendation: Make faster HO to HILTONOD2 and make faster HO from RATUPLZOD1 to GRAHANIAGAOD2Log File: 0413_02.log4. Jl. Jend. Sudirman (NN) - CLOSEDConfidential HANDOVER DELAYED (4)

Problem Description: SALONCRISTIEOG1 dragging the call with bad SQIServing Cells: SALONCRISTIEOG1 & BLOKMPLZOG2Recommendation: Make faster HO from SALONCRISTIEOG1 to BLOKMPLZOG2Log File: 0303_08.log2. Jl. Panglima Polim (NS)Confidential HANDOVER DELAYED (4)

Problem Update: SQI improved after neighbor auditServing Cells: SALONCRISTIEOG1, BLOKMPLZOG2 and BLOKMPLZOG1Recommendation: Performance monitoringLog File: 0331_14.log2. Jl. Panglima Polim (NS) - ClosedConfidential NO BEST SERVING/DOMINANT SERVER (5)

Problem Description: Low coverage and no best serving cell causing bad SQIServing Cells: CIDODOLMG1, POSPENGUMBENMG2, KEBONSIMPRUGMG2 and RAWASIMPRUGMG3Recommendation: Coverage adjustment from KOBONSIMPRUGMG&MD2 make as best serving cellsLog File: Febri_0512_17.log34. Jl. Kebayoran Lama NS (Open)Confidential NO BEST SERVING/DOMINANT SERVER (5)

Problem Description: SQI performance improvedServing Cells: CIDODOLMG1, POSPENGUMBENMG2, KEBONSIMPRUGMG2 and RAWASIMPRUGMG3Recommendation: Performance monitoringLog File: Faze_0616_06.log34. Jl. Kebayoran Lama NS (Closed)Confidential NO BEST SERVING/DOMINANT SERVER (6)

Problem Description: No best serving cell and poor coverageServing Cells: PETAMBURANMG/MD1, HTLPETAMBURANMG/MD3, PLNSLIPIMG/MD1, PLZSLIPIMG/MD 1&2Recommendation: Coverage adjustment from HTLPETAMBURANMG/MD3 and PLZSLIPIJAYAMG/MD2 Log File: 1222_05.log1. Jl. Brigjen Katamso Darmokusumo (TP1)Confidential NO BEST SERVING/DOMINANT SERVER (6)

Problem Description: SQI improved by arrangement coverageServing Cells: PETAMBURANMG/MD1, HTLPETAMBURANMG/MD3, PLNSLIPIMG/MD1, PLZSLIPIMG/MD 1&2Recommendation: Performance monitoring Log File: 0126_03.log1. Jl. Brigjen Katamso Darmokusumo (TP1) (CLOSED)Confidential

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