Retainibility

1. LTE KPI
Retainability SARR(Session Abnormal Release Rate)
eNodeB Initiated
pmErabRelAbnormalEnb , pmErabRelAbnormalEnbQci
pmErabRelAbnormalEnbArp , pmErabRelNormalEnb
pmErabRelNormalEnbQci ,pmErabRelNormalEnbArp
mErabRelNormalEnbUserInactivity , pmErabRelNormalEnbAct
pmErabRelNormalEnbActArp , pmErabRelNormalEnbActQci
pmErabRelAbnormalEnbAct , pmErabRelNormalEnbUserInactivityQci
UE Lost
pmErabRelAbnormalEnbActUeLos
(UE unreachable)
Radio Cause
Coverage issues
pmBadCovEvalReport
pmRadioTbsPwrRestricted
pmBadCovSearchEvalReport
maximumTransmissionPower
partOfSectorPower
confOutputPower
crsGain
pdschTypeBGain
Indoor coverage issue (Small cell , PICO , DOT , Hetnet)
Physical changes (Tilt , Azimuth , height of antenna)
Audit cell reselection parameters , Tune DL power related parameters (as mentioned beside)
Check if there is scope of new site
Poor DL SINR (CQI) pmRadioUeRepCqiDistr , pmRadioUeRepCqiDistr2
maximumTransmissionPower
partOfSectorPower
confOutputPower
crsGain
pdschTypeBGain
Tune related parameters (as mentioned beside) , Audit cell reselection parameters
Physical optimization (Tilt , Azimuth , height of antenna) , also Identify overshooting cells causing interference in DL
UL RSSI
pmRadioRecInterferencePwr
pmRadioRecInterferencePwrPucch
pmRadioRecInterferencePwrPrb1~100
pmSinrPucchDistr , pmSinrPuschDistr
pZeroNominalPucch
pZeroNominalPusch
Check Power control parameters , Features like IRC & UL FSS can help to reduce UL interference.
Check for Loose Connectors,Faulty Antenna(Tx & Rx antenna ports),VSWR alarms,Faulty TMA Connections/settings.
External interference (cable tv , repeaters (due to power leak issues) , airport , police communication system etc..)
HW and other causes Check HW issues , alarms , improper cabling , connector issues , DUS Board error
Handover Failure
pmErabRelAbnormalEnbActHo
(handover execution failure)
PCI confliction or confusion Audit PCI of near by sites , also check if there is overshooting cell creating conflict
Coverage issues
pmBadCovEvalReport
pmRadioTbsPwrRestricted
pmBadCovSearchEvalReport
maximumTransmissionPower
partOfSectorPower
confOutputPower
crsGain
pdschTypeBGain
Indoor coverage issue (Small cell , PICO , DOT , Hetnet)
Physical changes (Tilt , Azimuth , height of antenna)
Audit cell reselection parameters , Tune DL power related parameters (as mentioned beside)
Check if there is scope of new site
Poor DL SINR (CQI) pmRadioUeRepCqiDistr , pmRadioUeRepCqiDistr2
maximumTransmissionPower
partOfSectorPower
confOutputPower
crsGain
pdschTypeBGain
Tune related parameters (as mentioned beside) , Audit cell reselection parameters
Physical optimization (Tilt , Azimuth , height of antenna) also Identify overshooting cells causing interference in DL
UL RSSI
pmRadioRecInterferencePwr
pmRadioRecInterferencePwrPucch
pmRadioRecInterferencePwrPrb1~100
pmSinrPucchDistr , pmSinrPuschDistr
pZeroNominalPucch
pZeroNominalPusch
Check Power control parameters , Features like IRC & UL FSS can help to reduce UL interference.
Check for Loose Connectors,Faulty Antenna(Tx & Rx antenna ports),VSWR alarms,Faulty TMA Connections/settings.
External interference (cable tv , repeaters (due to power leak issues) , airport , police communication system etc..)
HW issues & Alarms
Alarms Alarm need to monitor , some alarms need to monitor are VswrOverThreshold , Serviceunavailable (S1 connection failure) , Gigabit Ethernet Link Faul
Availability
Cell down
Cell Down Auto
pmCellDowntimeAuto
pmCellDownLockAuto
eNodeB Cause
Configuration issues ensure proper configuration , especially for all new site which are integrated recently
Auto Restart
Ensure the eNodeB structure of the restart, MP、Baseband or RRU
lh all llog -l (do complete eNB health checkup)
Baseband Startup issue Baseband Trace can be used , te enable all bbmcBbOmMeSwU
Transport Cause S1 issues pmErabRelAbnormalEnbActTnFail check for alarms like Service Unavailable(S1 connection failure)
EPC Cause check for alarms like Service Unavailable(S1 connection failure) , Ip packet loss "above" SGW
Cell Down Manually
pmCellDowntimeMan
pmCellDownLockMan
Operation Cause
manually locked during network configuration issues ((eg. adding/changing/removing hardware)
manually locked during parameter change (eg. activate feature)
Sleeping Cell
pmRaAttCbra
pmRaSuccCbra
pmRaFailCbraMsg2Disc
pmRaAttCfra
pmRaSuccCfra
pmRaFailCfraMsg2Disc
pmRaAllocCfra
pmRrcConnEstabAtt
pmRrcConnSucc
Verify symtoms for sleeping cell
Catch Trace(Baseband) trace from MSG1 to MSG5 , verify symtoms for sleeping cells
Non-access issue
Configuration issue
Power setting issue Check SectorEquipmentFunction:ConfiguredOutputPower & Eutrancelltdd:partOfSectorPower
Idle mode parameter issue Check Eutrancelltdd MO cell selection and reselection parameters & 3G&2G cell reselection parameter/feature
Operation issues Cell Barred Check Cell Barred , acBarring for different scenarios
HW issues Check HW issues , alarms , improper cabling , connector issues , DUS Board error
pmErabRelAbnormalEnbActHpr
(handover preparation failure)
License issue:
pmHoPrepRejInLicConnUsers
capacityUnitConnectedUsers
gracePeriodTimeLeft
Check "licenseCapacityConnectedUsers" of Target cell
Also Graceperiod should be noticed to exceed the licensed capacity limits for a limited periodof timeOffload traffic from target cel
pmHoPrepRejInLicMob Audit licenseState,featurestate,servicestate & other paramter related to Intra freq & Inter freq HO feature
pmHoPrepRejInLicMultiErab Audit licenseState,featurestate,servicestate & other paramter related to MultiErabsPerUser feature
pmHoPrepRejInLicRlcUm Audit licenseState,featurestate,servicestate & other paramter related to RlcUm feature
Load:
pmHoPrepRejInHighLoad (MP load control)
pmHoPrepRejInOverload (procedure latency supervision)
Check these counters on target cell , Reduce no. of HO by physical opti or features (UE Level Oscillating Handover Minimization & Automated Mobility Optimization)
MP capacity of DUS is higher than DUL , to increase MP capacity DUL can be replaced by DUS
Physical changes (Tilt , Azimuth , height of antenna) to offload traffic from target cell
Offload Target cell Load by changing Layering strategy, Idle mode cellreselection, connected mode mobility & Load balancing parameters
Admission reject pmHoPrepRejInBearerAdmissionRej
dlTransNwBandwidth , ulTransNwBandwidth
zzzTemp20 , zzzTemp21 , pmRrcConnMax , pmRrcConnLevSum
Audit UE Admission Control,Bearers (SRB & DRB) Admission Control,Transport Network Admission Control & Emergency call prioritization
Physical changes (Tilt , Azimuth , height of antenna) to offload traffic from target cell
Configuration issue
Check configuration issues (especially after new site is integrated)
(check MO ExternalEUtranCellTDD,EUtranCellRelation,TermPointToENB,TermPointToMme)
(also check config para ex. Activeplmnlist,PCI , TAC , EutranFrequencyRef , IP address of TermPointToENB & MME)
Other checks
Availability
Cell down
Cell Down Auto
pmCellDowntimeAuto
pmCellDownLockAuto
eNodeB Cause
Configuration issues ensure proper configuration , especially for all new site which are integrated recently
Auto Restart
Ensure the eNodeB structure of the restart, MP、Baseband or RRU
lh all llog -l (do complete eNB health checkup)
Baseband Startup issue Baseband Trace can be used , te enable all bbmcBbOmMeSwU
Transport Cause S1 issues pmErabRelAbnormalEnbActTnFail check for alarms like Service Unavailable(S1 connection failure)
EPC Cause check for alarms like Service Unavailable(S1 connection failure) , Ip packet loss "above" SGW
Cell Down Manually
pmCellDowntimeMan
pmCellDownLockMan
Operation Cause
manually locked during network configuration issues ((eg. adding/changing/removing hardware)
manually locked during parameter change (eg. activate feature)
Sleeping Cell
pmRaAttCbra
pmRaSuccCbra
pmRaFailCbraMsg2Disc
pmRaAttCfra
pmRaSuccCfra
pmRaFailCfraMsg2Disc
pmRaAllocCfra
pmRrcConnEstabAtt
pmRrcConnSucc
Verify symtoms for sleeping cell
Catch Trace(Baseband) trace from MSG1 to MSG5 , verify symtoms for sleeping cells
Non-access issue
Configuration issue
Power setting issue Check SectorEquipmentFunction:ConfiguredOutputPower & Eutrancelltdd:partOfSectorPower
Idle mode parameter issue Check Eutrancelltdd MO cell selection and reselection parameters & 3G&2G cell reselection parameter/feature
Operation issues Cell Barred Check Cell Barred , acBarring for different scenarios
Alarms Check related alarms like Serviceunavailable (S1 connection failure,Hardware failure,GeneralHwError,GeneralSwError,Gigabit Ethernet Link Fault
MME pool If MME pool is different at source and target then HO-Preparation fail will be 100%, command "get . termpointmme" can be used to find out the MME pool IP
Target cell Target cell is prelaunch cell.(Primaryplmnreserved)
Tune HO related parameters
Intra LTE cellIndividualOffsetEUtran ; a3offset ; hysteresisA3 ; timeToTriggerA3
Inter freq LTE a5Threshold1RSRP ; a5Threshold2RSRP ; hysteresisA5 ; timeToTriggerA5 , a2TresholdRsrpPrim , ANR parameters
IRAT a2TresholdRsrpPrim ; hysteresisA2Prim ; timeToTriggerA2Prim ; b2Threshold1Rsrp ; b2Threshold2RscpUtra ; hysteresisB2 ; timeToTriggerB2
MCPC feature para a1a2SearchThresholdRsrp ; hysteresisA1A2SearchRsrp ; timeToTriggerA2Search ; a2CriticalThresholdRsrp ; hysteresisA2CriticalRsrp ; timeToTriggerA2Critical
Transport nw Issue pmErabRelAbnormalEnbActTnFail S1 or X2 interfaces DOWN (Transport Resource Unavailable) , Also check 3G collocated nodeb in term of SCTP LOSS
eNodeB Issue
pmErabRelAbnormalEnbActCd Check any planned activities , Check high temperature on DU,RU bord also Check eNodeb alarm logs , also it may be do to common transport network
HW and other causes Check HW issues , alarms , improper cabling , connector issues , DUS Board error
Other important parameters/features
Parameters RLC layer retransmissions
dlMaxRetxThreshold
ulMaxRetxThreshold
Features
Multi-Target RRC Connection Re-Establishment
Mobility Control at Poor Coverage
MME Initiated
pmErabRelMme , pmErabRelMmeArp
pmErabRelMmeAct , pmErabRelMmeHo
pmErabRelMmeActHo , pmErabRelAbnormalMmeAct
pmErabRelAbnormalMMeActQci , pmErabRelAbnormalMMeActArp
pmErabRelMmeQci
pmErabRelMmeActEutra
(Release due to Eutran generated reason)
If MME related issue is their many sites in the NW will be impacted & if Core related issues is there all sectors of site will be impacted.
If issue is in single sector then mostly it will be case of HW or radio related issues, Check HW issues , alarms , improper cabling , connector issues
Check Radio Condition (low coverage , UL_Pathloss, NOISE_PUSCH/PUCCH) (refer radio cases above) also Check Traffic Volume , also check if there is sudden spike in traffic)
Check if multi target RRC connection reestablishment feature is functioning properly.
pmErabRelMmeActUnspecified
Check is required on both Radio & core side
If MME related issue is their many sites in the NW will be impacted & if Core related issues is there all sectors of site will be impacted.
If issue is in single sector then mostly it will be case of HW or radio related issues (check following) , Check HW issues , alarms , improper cabling , connector issues
Check Radio Condition (low coverage , UL_Pathloss, NOISE_PUSCH/PUCCH) (refer radio cases above) also Check Traffic Volume , also check if there is sudden spike in traffic)
If there is no issue on eNB side , core team should troubleshoot the issue , Traces at core side can help to do RCA
pmErabRelMmeActUserInactivity Release due to long UE inactivity
Parameter
Action plan
Counters
Legend:
RETAINABILITY-L14B
EGI-Network Engineering- LRAN