KPI (1): Low CSSR CS

Check which part of the CSSR KPI causes the low value: RRC Setup or RAB Setup or Both.

RRC Fail Counter

Problem Classification Measurement Item Sub Items

Congestion RRC.FailConnEstab.Cong

VS.RRC.Rej.ULIUBBand.Cong, VS.RRC.Rej.DLIUBBand.Cong

VS.RRC.Rej.ULPower.Cong, VS.RRC.Rej.DLPower.Cong

VS.RRC.Rej.ULCE.Cong, VS.RRC.Rej.DLCE.Cong

VS.RRC.Rej.Code.Cong

RF Problem

RRC.FailConnEstab.NoReply

VS.RRC.Rej.Redir.Dist

VS.RRC.Rej.Redir.InterRat

VS.RRC.Rej.Redir.IntraRat

VS.RRC.Rej.Redir.Service

Transmission Problem

VS.RRC.Rej.RL.Fail

VS.RRC.Rej.TNL.Fail

Analysis Process:

Transmission Problem:

Relative alarms to identify faults on the transmission path or the transmission boards of RNC/NodeB.

Congestion Problem:

1. Check the Admission Control thresholds. 2. Take appropriate measures to relieve congestion, e.g. activate LDR (Load Reshuffling),

OLC (Overload Control) algorithms, and to increase capacity.

RF Problem:

1. Check coverage in the failure points. 2. Check if most failures occur in cell border (most probably they are). 3. Check FACH power. 4. Check DL interference in the cell: is there a pilot pollution issue? 5. Check UL interference in the cell.

RAB Setup failure

Problem Classification Measurement Item Sub Items Sub Items

Congestion VS.RAB.FailEstPS.RNL VS.RAB.FailEstPS.Unsp

VS.RAB.FailEstPs.ULPower.Cong

VS.RAB.FailEstPs.Code.Cong

VS.RAB.FailEstab.PS.DLIUBBand.Cong

VS.RAB.FailEstab.PS.ULIUBBand.Cong

VS.RAB.FailEstPs.ULCE.Cong

VS.RAB.FailEstPs.DLCE.Cong

VS.RAB.FailEstPs.DLPower.Cong

RF Problem

VS.RAB.FailEstabPS.UuFail

VS.RAB.FailEstabPS.IubFail

Transmission VS.RAB.FailEstPS.TNL

Analysis Process:

Transmission Problem:

Check transmission issue on Iu-CS interface; check relative alarms and its history.

RF Problem:

Check invalid parameters

Check inter-RAT HO and if the failure point is in RNC border

Check the relative RB Setup failure counters to get more details on the failure cause.

Congestion Problem:

Check the Admission Control thresholds.

Take appropriate measures to relieve congestion, e.g. activate LDR, OLC algorithms, and to increase capacity.

Refer to 3G Capacity Optimization document

KPI (2): Low CSSR PS

Check which part of the CSSR KPI causes the low value: RRC Setup or RAB Setup or Both

RRC Fail Counter

Problem Classification Measurement Item Sub Items

Congestion RRC.FailConnEstab.Cong

VS.RRC.Rej.ULIUBBand.Cong, VS.RRC.Rej.DLIUBBand.Cong

VS.RRC.Rej.ULPower.Cong, VS.RRC.Rej.DLPower.Cong

VS.RRC.Rej.ULCE.Cong, VS.RRC.Rej.DLCE.Cong

VS.RRC.Rej.Code.Cong

RF Problem

RRC.FailConnEstab.NoReply

VS.RRC.Rej.Redir.Dist

VS.RRC.Rej.Redir.InterRat

VS.RRC.Rej.Redir.IntraRat

VS.RRC.Rej.Redir.Service

Transmission Problem

VS.RRC.Rej.RL.Fail

VS.RRC.Rej.TNL.Fail

Analysis Process:

Transmission Problem:

Relative alarms to identify faults on the transmission path or the transmission boards of RNC/NodeB.

Congestion Problem:

3. Check the Admission Control thresholds. 4. Take appropriate measures to relieve congestion, e.g. activate LDR (Load Reshuffling),

OLC (Overload Control) algorithms, and to increase capacity.

RF Problem:

6. Check coverage in the failure points. 7. Check if most failures occur in cell border (most probably they are). 8. Check FACH power. 9. Check DL interference in the cell: is there a pilot pollution issue? 10. Check UL interference in the cell.

RAB Setup failure

Problem Classification Measurement Item Sub Items Sub Items

Congestion VS.RAB.FailEstPS.RNL VS.RAB.FailEstPS.Unsp

VS.RAB.FailEstPs.ULPower.Cong

VS.RAB.FailEstPs.Code.Cong

VS.RAB.FailEstab.PS.DLIUBBand.Cong

VS.RAB.FailEstab.PS.ULIUBBand.Cong

VS.RAB.FailEstPs.ULCE.Cong

VS.RAB.FailEstPs.DLCE.Cong

VS.RAB.FailEstPs.DLPower.Cong

RF Problem

VS.RAB.FailEstabPS.UuFail

VS.RAB.FailEstabPS.IubFail

Transmission VS.RAB.FailEstPS.TNL

Analysis Process:

Transmission Problem:

Check relative alarms transmission issue on Iub interface.

RF Problem:

Check coverage in the failure points. Check if it is in cell border (most probably it is).

Congestion Problem:

Check the Admission Control thresholds. Take appropriate measures to increase capacity.

KPI(3): High DCR CS

Check the unavailability or faults at problematic sites and its neighboring sites.

Check the distribution of call drops in the network; happens in specific areas or whole area.

Check the traffic distribution in the problematic areas. Check if there was an abnormal increase of the

traffic due to some event.

Problem Classification

Abnormal Release Indicator Sub-indicator (Level 2) Note

RF Problem VS.RAB.AbnormRel.CS.RF

VS.RAB.AbnormRel.CS.RF.ULSync

VS.RAB.AbnormRel.CS.RF.UuNoReply

VS.RAB.AbnormRel.CS.RF.SRBReset

Non-RF Problem

VS.RAB.AbnormRel.CS.OM CS RAB drops due to OM intervention, e.g. cell was blocked

VS.RAB.AbnormRel.CS.Preempt CS RAB drops due to preemption

VS.RAB.AbnormRel.CS.UTRANgen

CS RAB drops due to UTRAN generated reasons; indicates hardware failure on RAN equipment; check alarms in order to identify the faulty part; repair or replace the faulty part once identified.

VS.RAB.AbnormRel.CS.OLC Released Due to congestion for Cell

VS.RAB.AbnormRel.CS.IuAAL2

CS RAB drops due to AAL2 failure; check transmission alarms to identify possible faults in the Iu-CS transmission path

Analysis Process:

DCR CD (RF Problem):

Check for missing neighbors

Check for pilot pollution (adjust physical config)

Check for UL interference. Check VS.MeanRTWP counter in order to see the value of UL

interference in the cell. If the value is higher than -97 dBm, then interference exists in the UL.

o Check internal interference:

Internal interference is usually caused by faulty connections in the antenna line.

Check thoroughly all relative connection

o Check external interference:

External interference is caused by external sources (e.g. TV/Radio stations, military

equipment, other networks equipment, etc.).

External interference will appear randomly throughout the day. Its direction will be

specific and it will affect more than one sites in the area.

Check neighboring sites to see if they face the same problem.

In case of poor coverage, adjust physical config.

KPI(4): High DCR PS

Problem Classification

Abnormal Release Indicator Sub-indicator (Level 2) Note

RF Problem VS.RAB.AbnormRel.PS.RF

VS.RAB.AbnormRel.PS.RF.SRBReset

VS.RAB.AbnormRel.PS.RF.ULSync

VS.RAB.AbnormRel.PS.RF.UuNoReply

VS.RAB.AbnormRel.PS.RF.TRBReset PS RAB drops due to RLC reset

Non-RF Problem

VS.RAB.AbnormRel.PS.OM PS RAB drops due to OM intervention, e.g. cell was blocked

VS.RAB.AbnormRel.PS.Preempt PS RAB drops due to preemption

VS.RAB.AbnormRel.PS.OLC Released Due to congestion for Cell

VS.RAB.AbnormRel.PS.GTPULoss

PS RAB drops due to GTPU failure; check transmission alarms to identify possible faults in the Iu-PS transmission path

KPI (5): Low ISHO CS

Problem Classification Failure Indicator Note

Preparation phase

VS.IRATHO.FailRelocPrepOutCS.TAlExp.GCell

TRELOCalloc expiry (the timer that waits for the RELOCATION COMMAND after the REOCATION REQUIRED expires; check if the RNC-MSC links are normal; check CN transmission parameters)

VS.IRATHO.FailRelocPrepOutCS.TgtFail.GCell

Relocation Failure in target CN/RNC or target system (check the CN configuration; check if the BSS supports the relocation)

IRATHO.FailRelocPrepOutCS.ReloNoSup Relocation not supported in target RNC or target system

IRATHO.FailRelocPrepOutCS.NoResAvail

No Resource Available (the BSC has no resources for the UE access or the 2G MSC has no information about the target cell)

IRATHO.FailRelocPrepOutCS.HigherTrafficLod Traffic load in the target cell higher than in the source cell

IRATHO.FailRelocPrepOutCS.UKnowRNC Unknown Target RNC (the LAI of the 2G target cell is not configured in the MSC)

Execution phase

IRATHO.FailOutCS.CfgUnsupp

Configuration Unsupported (the configuration assigned in the HANDOVER FROM UTRAN COMMAND is not supported by the UE; check configuration of the encryption parameters; might also be UE problem)

IRATHO.FailOutCS.PhyChFail

Physical Channel Failure (indicates poor 2G signal check the handover thresholds in both 3G and 2G configurations; check for interference in the 2G target cell)

VS.IRATHO.FailOutCS.NoReply Timeout of waiting for IU RELEASE COMMAND messages during an outgoing inter-RAT CS handover

Analysis Process:

Preparation phase

Check if the RNC-MSC links are normal

Check if theres any relocation failure

Check if relocation not supported in target RNC or target system

No Resource Available BSC has no resources for the UE access MSC has no information about the target cell Need consistency checking between 2G and 3G NDB

Congestion

Execution phase

Check if there are any missing 2G neighbors

Check the inter-RAT handover parameters

Improper settings may cause the handover not to be performed on time: events 2D/2F parameters, events 3A, 3C parameters

Check the handover thresholds in both 3G and 2G configurations

Database 2G-3G Consistency Check: Cross check 2G CFGMML with External 2G on 3G CFGMML (parameter check on 2G: MCC, MNC, LACCI, NCC, BCC, BCCH, RAC) Old database still not yet erased

Check for Interference in the 2G target cell

Check for SD and TCH blocking in the 2G target cell

KPI (6): Low ISHO PS

Problem Classification Failure Indicator Note

Preparation phase

VS.IRATHO.FailRelocPrepOutPS.TAlExp.GCell

TRELOCalloc expiry (the timer that waits for the RELOCATION COMMAND after the REOCATION REQUIRED expires; check if the RNC-MSC links are normal; check CN transmission parameters)

VS.IRATHO.FailRelocPrepOutPS.TgtFail.GCell

Relocation Failure in target CN/RNC or target system (check the CN configuration; check if the BSS supports the relocation)

IRATHO.FailRelocPrepOutPS.ReloNoSup Relocation not supported in target RNC or target system

IRATHO.FailRelocPrepOutPS.NoResAvail

No Resource Available (the BSC has no resources for the UE access or the 2G MSC has no information about the target cell)

IRATHO.FailRelocPrepOutPS.HigherTrafficLod Traffic load in the target cell higher than in the source cell

IRATHO.FailRelocPrepOutPS.UKnowRNC Unknown Target RNC (the LAI of the 2G target cell is not configured in the MSC)

Execution phase

IRATHO.FailOutPS.CfgUnsupp

Configuration Unsupported (the configuration assigned in the HANDOVER FROM UTRAN COMMAND is not supported by the UE; check configuration of the encryption parameters; might also be UE problem)

IRATHO.FailOutPS.PhyChFail

Physical Channel Failure (indicates poor 2G signal check the handover thresholds in both 3G and 2G configurations; check for interference in the 2G target cell)

VS.IRATHO.FailOutPS.NoReply Timeout of waiting for IU RELEASE COMMAND messages during an outgoing inter-RAT PS handover

Analysis Process:

Preparation phase

Check if the RNC-SGSN links are normal

Check if theres any relocation failure

Check if relocation not supported in target RNC or target system

No Resource Available BSC has no resources for the UE access MSC has no information about the target cell Need consistency checking between 2G and 3G NDB

Congestion

Execution phase

Check if there are any missing 2G neighbors

Check the inter-RAT handover parameters Improper settings may cause the handover not to be performed on time: events 2D/2F parameters, events 3A, 3C parameters Check the handover thresholds in both 3G and 2G configurations

Database 2G-3G Consistency Check Cross check 2G CFGMML with External 2G on 3G CFGMML (parameter check on 2G: MCC, MNC, LACCI, NCC, BCC, BCCH, RAC) Old database still not yet erased

Check for Interference in the 2G target cell

Check for PDCH blocking in the 2G target cell

KPI (6): Low IFHO PS

Failure Indicator Note

VS.HHO.FailInterFreqOut.CfgUnsupp

Configuration unsupported (the UE doesnt support the configuration assigned by the RNC in the PHYSICAL CHANNEL RENONFIGURATION message indicates possible UE problem however this case almost never happens in commercial networks)

VS.HHO.FailInterFreqOut.PyhChFail Physical channel failure (indicates poor coverage)

VS.HHO.FailInterFreqOut.ISR Incompatible simultaneous reconfiguration (the UE feedbacks that the HHO procedure is not compatible with other concurrent processes. This case almost never happens; it indicates defective UE)

VS.HHO.FailInterFreqOut.CellUpdt Cell update occurred (this case never happens in commercial network)

VS.HHO.FailInterFreqOut.InvCfg

Invalid configuration (some IEs in the PHYSICAL CHANNEL RENONFIGURATION message are invalid for the UE; this case almost never happens; indicates possible UE problem)

VS.HHO.FailInterFreqOut.NoReply No response on the air interface (indicates poor coverage or even a UE problem)

VS.HHO.FailInterFreqOut.PrepFail

VS.HHO.FailInterFreqOut.RLSetupFail

Analysis Process:

Optimizing Neighbor based on scenario given

Blind HO setting

Check availability/alarm on surroundings

Check if there are any missing neighbors

Check the inter-frequency handover parameters

Improper settings may cause the handover not to be performed on time

Check events 2D/2F parameters

Check events 2B, 2C parameters