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Optimization LTE

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ACCESSIBILITY
o IDLE
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Reference signal is used to measure quality
Cell Selection
♦ QRxLevMin -128 to -110 to discourage camping QRxLevMinOffset 0 to 2 will
discourage camping,
♦ Qqualmin -22 to 18 to discourage camping
♦ Pcompensation max(PEMAX –PPowerClass, 0), pMaxServingCell, pMaxGeran
− PMAX (max UE power)
− Criteria for camping of Less power UEs is hard, pMaxServingCell 1000
Srxlev = Qrxlevmeas – (Qrxlevmin + Qrxlevminoffset) - Pcompensation
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Reselection
♦ Start Reselection
− SIntraSearch 29*2=-58dBm to 31 will encourage reselection
− sNonIntraSearch 2 to 5 will discourage IRAT reselection,
-114+5*2=-104dBm
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TcrMaxConnMode (mobility calc) T_CRMAX_30S to T_CRMAX_60S will
discourage reselection but increase precision, celResTiF, sIntrasearch,
sNonIntrsearch
High mobility scaling QHystSfHigh DB0_Q_HYST_SF_HIGH(0dB) to
DB_2_Q_HYST_SF_HIGH will discourage reselection, qRxlevminoffset 0
to 2
− TreselectionRAT increase to decrease reselection, treSelection 7s
♦ Reselection Decision
− IdleQhyst1s (current cell) 4 to 2 will discourage sticking to current cell qHyst,
qHyst 4
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Cell offset qOffsetCellEUtran, qOffsetCell, qOffCell, interTResEut,
qRxLevMinInterF, offsetFreq 2 to 0
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CellReselPriority 0 to 2 for high priority, cellReselectionPriority 5 to 3
discourage reselection, threshXHighHrpd, tReselectionEutra 2 to 4,
tReselectionEutraSfHigh 3 to 2
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NcellReselectionHigh 16 to 10  UE enters high mobility state earlier
threshXHigh, threshXLow, tReselectionEutraSfHigh, threshServingLow 62,
sPrioritySearch1,
interFrqThrH, tResEutSF, eutResTiFHM, celResTiFHM, cellReSelPrio 3 to
0 will discourage, mobStateParamNCelChgHgh, mobStateParamTEval,
qRxLevMinOffset 0 to 2dB, q-RxLevMin, spStResPars, qHystSfHigh,
tReselEutr, timeToTriggerSfMedium, tResUtra, tResUtraSF, utrResTiFHM
Qrxlevmeas
Rs = Qmeas,s + QHyst
Rn = Qmeas,n - Qoffset
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Tevaluation 30 to 60s, tEvaluation 240
• T320
ATTACH T3410 (UE), T3450 (eNodeB)
System Information Messages SIB1(Access/Message scheduling,
reselection),SIB2(UE timers,common/shared channel, UL RBs),SIB3(intra-freq reselect)
systemInformationBlock3,SIB4(Intra neigh),SIB5 (inter-freq neigh), SIB6(Reselect to
WCDMA),SIB-7(Reslect to GSM),SIB8(Reselect to CDMA)
• Sib3Period RF16 to RF32 less resources used but delay in access,
maxCrSibDl, si4Periodicity
CellRadius
RRC setup success rate (service)
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pZeroNominalPucch -117
RB=SRB+DRB
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SRB0 is for RRC messages transmitted over the Common Control Channel CCCH
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SRB1 is transmitted over the Dedicated Control Channel DCCH. RRC connection
establishment is Signaling Radio Bearer-1. Theis is for NSN and RRC
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SRB2: bearing NAS signaling and transmitted over the DCCH, srbSchedWeightDl. This is for
NAS and RRC of high priority
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DRB bears data maximum of eight DRBs per UE with eNodeB
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T302 4 to 6 s, timer b/w retries for RRC connection establishment
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tlnactivityTimer
Causes emergency highPriorityAccess Mobile terminating Mobile Originating Signaling and mo-Data.
RRC failures L.RRC.ReEst.ReconfFail.Rej L.RRC.ReEst.HoFail.Rej, RA measurement(Random Access
failures), PDCP discards, s1RetryTimer 30 to 40,
• T300-5, T301, 200 to 300 ms, N310, N311
• T310 indicates physical failure 200 to 300
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T3410 UE timer supervises attach request
T3417, T3421 or T3430 retransmission timers
T3421 UE timer supervises detach procedure
RRC Setup Success Rate (Signaling)
PRACH (SIB2)
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T311 10000 to 150000 ms, RRC reestablishment
T3446
T3460 supervises authentication request.NAS timer
T3470 sueprvises identity request. NAS timer
prach-ConfigurationIndex, Max Preambles, contention/non contention (specified RACH), Power
ramping step DB0 to DB2, Preamble initial received target power DBM_104 to DBM_100, RA retries,
PreambInitRcvTargetPwr DBM_120(-120dBm) to DBM_92(-92dBm)  performace of cell at the cost
of interference on others, RachAlgoSwitch, maxCrRa4Dl, PRACH cyclic shift, prachFreqOff,
prachPwrRamp, preambTxMax, raContResoT, raMsgPoffGrB, raNondedPreamb, raPowRampSetup,
raRespWinSize, rootSeqIndex, ulpcIniPrePwr, ulpcRarespTpc, RACH density
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Early contention resolution can improve the Access success rate
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accessBarringTime s32  T303
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numberOfPRBsForDynamicallyScheduledPUSCHForRACHRegion, maxHARQmsg3Tx,
maxRACHTransmitPower, pRACHPreambleDetectorThreshold, pRACHpowerSetting,
prachFrequencyOffset, preambleInitialReceivedTargetPower, preambleTransMax,
preambleTransmitPowerStepSize, adaptiveMsg3PowerControlEnable,
sctpAccessAssociationMaxRetrans, sctpAccessEstablishmentMaxRetries
RA (Random Access) update for service request, location update, and paging. RACH is provided to UE.
o Contention (preamble collision) initial RRC connection establishment, RRC connection
reestablishment, uplink data arrival
o Non Contention (preambles allocated) handover, downlink data arrival
o BackOffSwitch adjust the back off time dynamically to relieve load on RACH
o RACH process influences the call setup delay, handover delay, data resuming delay, call setup
success rate and handover success rate.
o AcBarringFactorForCall P95(95%) to 80 will discourage access
ATTACH
o Incorrect LAC at MSC, TAC at MME
• T3412 TAC update
• T3414 UE attach with NAS
• S1_implicitDetachTimer
• S1_MobileReachableTimer
o SON
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RACH load (call arrival rate, HO rate, tracking area update, traffic pattern)
Interference on PUSCH channel
Paramaters that can be controlled are PRACH configuration index, RACH preamble split,
RACH backoff parameter value, PRACH transmission power control parameters
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FACH
PAGING
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Discarded Paging Messages over the Uu Interface, pagingDiscardTimer 3 to 5s, T3413, ,
DefaultPagingCycle or DRX cycle rf128 to fr64  shorter paging cycle. AS (UE & eNodeB) RRC service
request, location update, and paging, maxCrPgDl, maxNumRrc, pagingNb, raCrntiReuseT,
modificationPeriodCoeff 2, rrcConnReestActive 0 to 1  RRC success, cellRange 15 to 10Km  success,
coverageIndicator, nrOfRrcConnectedReserved, dlGbrAdmThresh,
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T=defaultpagingcycle 1T to 1/2T  less paging time, high paging traffic, fewer groups, more UEs in a group,
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nB T to 1/4T fewer and larger groups, less paging capacity
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T=defaultpagingcycle 1T to 2T  more paging time, low paging traffic, more groups, less UEs in a group,
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Nb  ONET (1T) to TWOT(2T) more paging capacity
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maxNoOfPagingRecords3 to 5 more UEs in a paging message
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Single paging message can accommodate a maximum of 16 paging records. Small TA  more LAC updates
and chances of missing paging message increase
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pagingForceMCSmin -1 to 2 min MCS scheme
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NAS (UE & MME) procedure consists of attach, detach, tracking area (TA) update, service request, and
extended service request.
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RRC connection reestablishment caused by handover failure, RRC reconfiguration failure, or radio link failure
downlink data arrival. uplink data arrival.
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initial coding is set by parameter
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CCCH
o SRB-0
o RRC(SRB-1) over DCCH Connection Request (Over CCCH from UE to eNodeB) UE
context/SRB1 allocation  RRC Connection Setup (eNodeB to UE)  RRC Connection Setup
Complete (UE to eNodeB)  Initial UE Message (eNodeB to MME)  Initial Context Setup message
(MME to eNodeB)  Security Mode command (eNodeB to UE)RRC Connection Reconfiguration
message(eNodeB to UE) RRC Connection Reconfiguration Complete message (UE to eNodeB)
o RRC(SRB-2) for ERABover DCCH,
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Signaling Link Release RRC Release UeInactiveTimer 1800 to 2000s, load rebalancing
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ERAB Setup Success Rate (VoIP)
ERAB Setup Success Rate (All)
o E-RAB establishment = Signaling Radio Bearer-2 (SRB2) establishment and Data Radio Bearer (DRB)
establishment. ERAB=RB(Um)-S1(S1)
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Radio Network Unavailability Rate
9 Radio Bearers RadioBeare rs _QCI _ 1 (highest) to 9
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RRC reconfiguration establishment, modification and Release of RBs
o SRB2 Inititial Context Setup Request (MME to eNodeB)  RRC connection reconfiguration
(enodeB to UE) RRC connection reconfiguration complete (UE to eNodeB) Intial context setup
(eNodeB to MME) ERAB setup request (MME to eNodeB)  RRC reconfiguration (enodeB to UE)
 RRC reconfiguration complete (UE to eNodeB)  ERAB setup response (eNodeB to MME)
o DRB ERAB modify request (MME to eNodeB)  RRC connection Reconfiguration (eNodeB to UE)
 RRC Reconfiguration complete(UE to eNodeB) ERAB modify response(eNodeB to MME). 8
DRB max.
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csFallbackPrio, s1RetryTimer, CS Fall-Back feature, GoldServiceArpThd 5 to 8  access, Qci1HoThd 90
to 95  access, NewGoldServiceOffset 10 to 5  access to gold at the cost of silver/copper,
a2TimeToTriggerRedirect, ocAcProbFac, acBarSig, sigAcProbFac, addAUeRrHo, qRxLevMinUtra
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RAC is based on No. of RRCs and active users, maxNumActDrb
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RRM, Dynamic Resource Allocation = Scheduling, resources modified are PRBs, Power, PDCCH/PUCCH
Resources, TX rank, baseband power, UlBasebandCapacity DlBasebandCapacity
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isRrcReEstablishmentAllowed
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Channels
o Downlink Control Channels
 PCFICH (no of symbols in PDCCH depending upon signaling), maxNrSymPdcch,
 PDCCH (scheduling, Downlink control info-DCI, MIMO mode, precoding, modulation, SIB,
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paging, broadcast, RACH response)
♦ DCI-0 uplink scheduling, RB group assignment, UL grant
♦ DCI-1 modulation, TPC, coding, RB assignment
♦ Resource allocation type-0
♦ Resource allocation type-1
♦ Resource allocation type-2 Resource indication Value-RIV (like pointer)
♦ DCI-2 downlink shared channel assignments in case of closed loop spatial Mux
♦ DCI-2A downlink shared channel assignments in case of open loop spatial Mux
♦ DCI-3 TPC
♦ CQI request
♦ cFI 1 to 2  increase in no. of PDCCH symbols, dynamicCFIEnabled
♦ initial coding is based on control data volume
PHICH ack/nack
PBCH MIB 40 ms, pBCHPowerOffset, initial coding is set by parameter
PSS & SSS symbol and frame timing as well as cell identities
RS reference signals for cell recognition, channel estimation, path loss estimation, and
handover measurement. soundRsEnabled. srsBandwidth, srsHoppingBw, srsPwrOffset,
nbrSRSperTTI
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PCI 504 = 168 (secondary x 3 (primary group)
PDSCH for downlink data, deliver RA-RNTI,TA, uplink grant, contention response by eNB,
Pb 0 to 3 & ReferenceSignalPwr 182 to 200 (20dBm)  high coverage/capacity but
interference on others, PDSCH power boosting, initial coding is set by parameter
Paging initial coding is set by parameter
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o Uplink channels
o PUCCH ack/nack, channel quality indication (CQI) reports, precoding matrix information (PMI)
and rank indication (RI) for MIMO, and scheduling requests (SR). Control info is ent on this
channel if PUSCH is not assigned to UE, pucchSize, pZeroNominalPucch, noOfPucchSrUsers,
dynamicPUCCHEnabled
o PUSCH data, freq hopping can be used, Intra-frame or Inter frame hopping, type 1 or 2 hopping
demodulation reference signal is used for channel estimation sounding reference signal provides
uplink channel quality CQI 16 values representing modulation scheme and coding format,
pZeroNominalPusch -103 (power), HoppingMode HoppingOffset,
cqiReportingModeAperiodic
o PRACH Preambles, initial access, handover, UL sync and UL SCH resource requests. initial
coding is set by parameter, NCS(prachCs)
o DRS Demodulation reference signals for channel estimation
o Sounding reference signals (SRS) are used to control frequency-dependent scheduling by the
eNodeB and PSrsOffsetDeltaMcsDisable -30 to -15 increase power of SRS. Estimate channel
quality, transmitted where there is no user data
Measurement messages are sent
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POWER CONTROL
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o FPC Fractional Power Control, applicable on Cell-specific reference signal, PBCH. estimation, and
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handover measurement.
Commands are sent through DCI
Reference signal power -57, PCFICH power -3175, PBCH power -3174, Synchronization signals
power, -3173, DBCH power -3172, Paging power -3171, Rach respond power
-3170, Prs Power -3169
SINR target and CQI, Downlik ICIC, scheduling affect power control
ICIC SON can change parameters HII, OI and DL TX Power indicator. ICIC changes scheduling strategies on
serving and neighbor cells
CellDlpcPdschPa (enable PC or even power distribution)
partOfRadioPower 100, confOutputPower 20 to 40, confOutputPower, maximumTransmissionPower,
rlfailureT, noutsyncInd, MinpwrRL, MinpwrMa, qRxLevMinInterF, dFpucchF1, dlPathlossChg,
dlpcMimoComp, enablePcPdcch, p0NomPucch, p0NomPusch, pMax, pMaxIntraF, pMaxOwnCell,
rxPowerScaling, tpcStepSize, ulpcAccuEnable, ulpcAlpha, ulpcEnable, ulpcIniPrePwr,
ulpcLowlevCch, ulpcPucchEn, ulpcReadPeriod, ulpcUplevCch, ulpcUpqualCch, pMaxUtra,
networkSignallingValue NS_01 (UE power attenuation)
Power Control of Signals
ReferenceSignalPwr 182(18dBm), offset of Sync signal SchPwr 0, PbchPwr -600(-3dB), PcfichPwr
-600(-3dB), They affect the coverage. The cell-specific reference signal is used for cell recognition,
channel estimation, path loss, Scaling factor Pb 1 to 3 (01,2,3) High Power of Reference signal but
at the cost of PDSCH, CellUlpcDedic, referenceSignalPower
PRACH PreambInitRcvTargetPwr DBM_104(-104dBm) to -102 , PwrRampingStep DB2 to DB4,
retries, Increase in Power  more interference but good accessibility, FilterRsrp
PDCCH Carrying RACH Response, Paging Messages, SIBs. RaRespPwr, PagingPwr -3171,
DbchPwr, They affect accessibility. Increase in Power  more interference but good accessibility.
PDCCH (RRC or SD)PC is dynamic w.r.t SIR targets and Static based on PdcchPwrDedi larger
value  less drops but less UEs accommodated, throughput and accessibility is affected,
PdcchBndPcSw is the switch for dynamic PC. maxNrSymPdcch,
PHICH carries HARQ and affects throughput. PC is dynamic w.r.t SIR targets and Static based on
PhichPcOff, PhichResource 1 to 2  more control resources. SINRRS(based on CQI) ≤SINRTarget then
increased power
PDSCH Increase Pb and Pa to increase power of PDSCH. PaCenterUe PA_0, PPDSCH_A, PO_PDSCH,
pDCCHPowerOffsetSymbol1, paOffsetPdsch, pDCCHPowerControlMaxPowerDecrease
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In Dynamic scheduling: CQI, transmission block, GBR, AMBR are considered to arrive at Pa
value
 In Semi-persistent scheduling: BLER target is considered
 ICIC informs if user is at the centre or edge
PUSCH (UE) affects throughput ,PCMAX, Alpha (0.4 to 0.8) good for cell edge users but not of system
performance, P0NominalPUSCH -67 to -58 large value  throughput of the cell increases but
network decreases, DeltaMcsEnabled 0 to 1  MCS value affects power control and throughput
increases
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Dynamic
♦ SINR based
♦ PH, RBs,
♦ RBs and OI of neighbor
 Semi persistent
♦ BLER
PUCCH (UE) affects throughput. The PUCCH carries the ACK/NACK information, CQIs, and
schedule request (SR) information related to downlink data. DeltaFPUCCHFormat1,
PucchAlgoSwitch, P0NominalPUCCH -105 to -100 increases throughput but decreases network
throughput
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primarySyncSignalPowerOffset
o SRS for uplink channel estimation and uplink timing, PSRS OFFSET, low power  low performance
o maximumTransmissionPower, confOutputPower, sectorPower, pMaxInterF,
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RaRspPwr PchPwr DbchPwr SchPwr PbchPwr PcfichPwr PrsPwr
o PaPcOff
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Open loop PC is based on path loss, broadcasted/RRC parameters
o Closed Loop PC is based on UL level and quality measurements, CELL_PWR_RED
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LOAD CONTROL
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T320
RacAlgoSwitch enable admission and load control algo, MlbAlgoSwitch load balancing algo
ulAccGbrAdmThresh
loadTargetForOCNS RB based
loadTargetForOCNSonPDCCH Power based
Load Monitoring
 Resource Limitation Indications
♦ Downlink power limitation indication
♦ PUCCH resource limitation indication
♦ Sounding resource limitation indication PUSCH
♦ Transport resource limitation indication
♦ Cell Congestion AqmAlgoSwitch (queueing at the cost of integrity)
 PRB usage, QoS satisfaction rate of GBR services, and resource limitation, DlRbHighThd 95
to 90 to encourage load control
♦ UlRbHighThd 95 to 90  Load control
 QOS Satisfaction Rate, based on QCI, admission based on QOS
Admission Control
 Check UE capability
 Resource prediction or QoS satisfaction rate of Admitted services or check no. of PRBs
♦ Resource: Allocation and Retention Priority (ARP), SRB for location updates and
detach, GoldUserArpThd 5 to 4 will increase priority, MaxNonGbrBearerNum 3000 to
4000 will enhance admission. By limiting the number of PRBs used by GBR
services, admission control increases the admission success rate
♦ QoS: admission threshold for new gold services is QcixHoThd plus
NewGoldUserOffset.
 Service preemption and Redirection, PreemptionArpThd 5(ARP value) to 3 to encourage
preemption
 MaxNonGBRBearerNum 3000 to 4000  admission
 GbrRbUseHighProportion, dlAccGbrAdmThresh
Load Balancing
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Intra-Frequency CIO(for connected mode), Qoffset in idle mode, Increase CIO and decrease
Qoffset
 IntraFreqMlbThd 60 to 50 for traffic shifting, LoadOffset 8 to 5,Neighbor with the lowest load
is considered or in A category
♦ Auto adjust CIO(for connected mode), Qoffset in idle mode
♦ CIO decrease to discourage HO to neighbor
 InterFreqMlbThd 60 to 55
 InterRatMlbThd 75 to 70 unidirectional only, based on UE attributes, service attributes, load
factors, and system performance.
 LoadExchangePrd 10s to 8 load control, imLoadBalancingActive,
threshServingLowHystMin, threshXHighHystMin
Congestion Control
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Preemption of GBR services with low energy efficiency rate (EER)
♦ PreemptionArpThd 5 to 3  congestion relief
GBR service rate downsizing
♦ CopperGbrCongProportion 90% to reduction 80 reduction  congestion relief
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Qci1CongThd 65 + CongRelOffset 20 < Qci1HoThd 90 to 85  congestion relief?
QcixHoThd is small overall QoS satisfaction rate of the admitted services is low but the
admission of incoming handovers is easy and drop rate may increase.
Energy efficiency rate (EER) depend upon data amount, PRB used, Downlink Power. More
data with less power  efficiency
♦ if ARP is >= LdcMeaArpThd 10 to 5  EER is calculated
♦ LdcMeaArpThd 10 to 13  congestion relief but drops increase
RETAINBILITY-CDR
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Call Drop Rate (VoIP)
Service Drop Rate (All)
Radio Network Unavailability Rate
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pZeroNominalPusch
RAB Failures ERAB relase causes (normal,abnormal,HO, congestion, unavailability), ERAB modification
causes, CQI measurement, MAC traffic retransmissions, no of users/edge users,PDCP discards/packet loss,
UE context releases, Check RACH and power parameters
Raw counters, Traces, Layer3, DT, PM events for diagnosis,
CSFallBackBlindHoCfg
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CQI 0 to 15, MCS 0 to 31, QC1 to QC9, RANK 1 to 4
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T310 indicates physical failure 200 to 300
UeInactiveTimer 1800 to 2000s
T321
Interference
o IRC works at physical layer  MIMO
o ICIC works at MAC layer, adjust center CCU and edge CEU UE loading
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dlInterferenceManagementActive switch, noOfRxAntennas, tHODataFwdReordering 50 to 100 ms
o tInactivityTimer, a5B2MobilityTimer, s1RetryTimer, tHODataFwdReordering, cellRange 15 to 10Km
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 low drops, coverageIndicator, ulInterferenceManagementActive, pMaxServingCell
MIMO
o Fading=Variance in SINR, 6dB gain with 4 antennas, adjust antenna weights to either minimize
interference gain (MRC) – white Noise or maximize signal gain (IRC) – colored interference, Closed
loop for slow moving and open loop for fast moving
E-RAB Release Service, handover, actRedirect, taTimerMargin, addAUeRrHo, dlTargetBler, p0NomPusch,
riEnable, riPerOffset, taMaxOffset, taTimer, ulamcSwitchPer, qQualMinUtra, qRxLevMinUtra
DeltaPreambleMsg3 4 to 6, DeltaFPUCCHFormat2a DELTAF2(2dB), P0NominalPUCCH
The definition of an abnormal release is that there shall be buffered data to be transmitted at the time of
release release of the E-RAB had a negative impact on the end-user.
o Voice release, normalized to releases
o PS releases, normalized to session time
♦ tlnactivityTimer
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T301
tTimeAlignmentTimer (Timer for TA UL sync)
T3411 failure in NAS signaling
T3410 failure in NAS signaling
T3430 failure in NAS signaling
T3417 failure in NAS signaling
T3440
groupHoppingEnabled, isRrcReEstablishmentAllowed, isS1EnhancementsAllowed,
isTrafficBasedContextReleaseAllowed, vswrUrgentThreshold 20 to 15  early trigger of alarm,
minimumCQIForFSS, connTimer, hARQMaxTimer, initialMCSIndexForBearerSetup, mIMOMode,
sctpAccessPathMaxRetrans
Closed Loop PC is based on UL level and quality measurements, CELL_PWR_RED, upper and lower
thresholds
MOBILITY
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General Causes
o Path imbalance, connectors, hardware, antenna tilt, serving/neighbor config, discontinuous coverage,
parameter settings, interference, cell degraded, PCI collisions,unavailabilities, check equipment
health,
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T304 supervises the Intra-LTE HO
Events
o A1(stop Inter-freq/Inter-RAT meas due to good quality), A2(start Inter-fre/Inter-RAT meas due to
good quality) RRC Connection Release with Redirect, A3(start intra-freq HO due to good neighbor)
better cell HO, A4(start inter-freq HO due to good neighbor, B1 (start inter-RAT HO due to good
neighbor), A5 coverage HO
 a3offset (serving) 30 to 40  discourage HO, timeToTriggerA3 40 to 64, hysteresisA2Sec
(neighbor) 10 to 20, hysteresisPm, reportAmountA2Prim 1 to 2  discourage A2,
reportAmountA3, reportIntervalA2Prim MS120 to MS240, reportQuantityA2Prim,
timeAndPhaseSynchCritical, x2BlackList, x2retryTimerStart, reportIntervalPm MS_480 to
MS_640, removeNcellTime 1 to 2 min, b1ThresholdEcNoUtra, hysteresisA3 3dB,
timeToTriggerA3 320 ms, filterCoefficientEUtraRsrp 4, tHODataFwdReordering 300 to 400
ms
UE Level Oscillating Handover Minimization feature
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SON
o AnrSwitch, MroSwitch, TpeSwitch
o Power Control
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Reference signal power -57, PCFICH power -3175, PBCH power -3174, Synchronization signals
power, -3173, DBCH power -3172, Paging power -3171, Rach respond power, -3170, Prs Power
-3169
o Neighbor-ANR
 maxReportCellsPm, measurementPriority, cellAddRankLimitEutran, isRemoveAllowed,
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cellAddRsrpOffsetEutran, cellAddRsrpThresholdEutran, removeNrelTime, ctrlMode,
maxMeasInterFreqEUtra, filterCoefficientEUtraRsrq, dlInterferenceManagementActive,
anrUesThreshInterFMax, minBestCellHoAttempts 1, x2BlackList, anrIntraFreqState, ANR
add cell threshold(%),Fast ANR PCI report amount, FastAnrRsrpThd, Fast ANR checking
period, covTriggerdBlindHoAllowed
 ANR is suggested for early phases
 anrEnable, isBlindPsHoToUtraFddAllowed
 Event triggered, Detection of missing neighboring, PCI collisions and abnormal neighboring
cell coverage
♦ NRTCellHOStatNum no of HOs with N and ANR DelCellThd 60 to 50% 
discourage deletion, HOSR with N, FastAnrRprtAmount,
 Drawbacks, HO delayed, data delay
 Periodic or Fast, detects only missing neighbor, FastAnrRprtInterval 2048 ms to 1024 ms will
speed up the ANR high speed, FastAnrIntraRatMeasUeNum 5 to 7 will improve HOSR.
Periodic measurements increase power and decrease throughput. FastAnrRsrpThd -102
to -90  make ANR tough URBAN
 Manual configure black and white list, intrFrBCList, intraEnbPrio, statusRepReq, A3 offsets,
a3ReportInterval, a3TimeToTrigger, addAUeRrHo, addAUeTcHo, cqiPerNp, dlsUsePartPrb,
maxNumAUeHo, p0NomPusch, p0UePusch, pMax, taMaxOffset, threshold1
 CsfbHoUtranTimeToTrig,
HO Parameter-MRO minimizes HO failures, service drops, Early/Drag/Ping-pong by adjusting
CIO. Enable during initial phase, MRO (Mobility Robust Optimization) feature optimizes the handover
parameters automatically. Deals premature handover, delayed handover, and ping-pong handover. It
changes the CIO, NcellOptThd, PingpongTimeThd, PingpongRatioThd 10 to 5 % (to encourage
MRO), MRO optimization period(min), Ncell optimization threshold(%)
 CIO, PingpongTimeThd 5 to 3, PingpongRatioThd 5 to 3  SON or MRO
 OptPeriod 1440 to 1300, OptParaThd 70 to 80% HOSR SON
♦ Ealry Hos>Delayed Hos  decrease CIO of neighbor
2. Detect early or late HO
o IRAT HO a2ThresholdRsrpPrim, a2ThresholdRsrpSec, b2Threshold1Rsrp,
Uemeasurementsactive, triggerQuantityA2Sec, hysteresisA2Prim, timeToTriggerA2Prim,
isForcedDrxForCsFallbackAllowed no to yes, isX2LoadIndicationAllowed,
threshold2EutraRsrq 8 (-7,-6.5) to 9 (-10,-9.5)  discourage A5, tReselectionEUTRAN,
maxTimeAllowedForCsfbMobilityAttempt
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o a3offset 30 to 35  discourage A3 or adding Intra freq neighbor, a1ThresholdRsrqPm
o pMaxGer, qRxLevMinGer
KPIs handover success rate, call drop rate, and ping-pong handover rate are set per QCI.
RACH-PDCCH
CIO decrease to discourage HO to neighbor. Intra-Frequency CIO(for connected mode), Qoffset in idle mode
LTE system uses hard handovers
RRC = connected mode, HO Types, Coverage, Load, service based,
Measurements gaps=compressed mode, frequency-specific offset 0 to 2 encourages HO
PBGT HO minBestCellHoAttempts, qOffsetFreq
Event-Triggered Periodical Reporting Hysteresis, time-to-trigger, filtering coefficient for L3-
EutranFilterCoeffRSRP FC0 to FC2 will delay HO, reporting configuration.
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Intra-frequency Handover Out Success Rate
o
o
o
Cell group ID is critical
In load based, CIO is changed automatically
A3 Mn + Ofn + Ocn – Hys > Ms + Ofs + Ocs + Off (IntraFreqHoA3Offset)

o
MeaBandwidth MBW-50 MBW-60, QoffsetFreq, IntraFreqHoA3Offset 2 to 4 will discourage
HO, IntraFreqHoA3Hyst 2 to 4(2dB), IntraFreqHoA3TimeToTrig 40 to 60 ms,
IntraFreqHoA3TrigQuan, IntraRATHoMaxRprtCell 4 to 6, IntraFreqHoRprtInterval 240 to
480ms, EutranFilterCoeffRSRP FC6 to FC8, IntraRATHoRprtAmount r2 to r4
 High values for cells with large signal fading variance
CellIndividualOffset (Auto) dB-0 to dB-2 will encourage HO

Ocs less value will discourage HO
Ocn (connected mode) high will encourage HO
Retry and Penalty
Handover failure  cell selection procedure  RRC connection re-establishment

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Measurement Gaps
GapPatternType
 GAP measurement pattern1 Tperiod 40ms, TGAP 6ms
 GAP measurement pattern2 Tperiod 80ms, TGAP 6ms
RRC connection re-establishment towards the selected cell only
Blind HO In the case of a load-based or service-based handover, the eNodeB may select a target cell in the
absence of the measurement information, in order to reduce the delay
o
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Inter-frequency Handover Out Success Rate
o A2 Ms + Hys < Thresh
 InterFreqHoA1A2Hyst 4 to 6(3dB), InterFreqHoA2ThdRSRQ -24(-12dB) to -28(-14dB),
o A4 Mn + Ofn (QoffsetFreq) + Ocn – Hys > Thresh
 QoffsetFreq 0 to 3 , InterFreqHoA4Hyst 4 to 6
 InterFreqHoA1ThdRSRQ -20 to -22, InterFreqLoadBasedHoA4ThdRSRP -103 to -105
 Timer304 GEAN IRAT timer
Load Based
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Based on frequency capability of UEs, ARPs, and resource usage
Handover In Success Rate
Inter-RAT Handover Out Success Rate (LTE to CDMA)
Inter-RAT Handover Out Success Rate (LTE to WCDMA)
o InterRatHoA2ThdRSRQ -20 to -22, InterRatHoA1ThdRSRQ -20 to -18,
InterRATHoUtranB1ThdEcN0 -20 to -16, LdSvBasedHoGeranB1Thd -98 to -94,
UtranFilterCoeffRSCP FC0 to FC2, InterRatHoRprtAmount, InterRatHoGeranRprtInterval
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T311 10000 to 150000 ms
Inter-RAT Handover Out Success Rate (LTE to GSM)
o
GeranFilterCoeff FC0 to FC2
T304 ms4000 to ms8000
redirectionInfoRefPrio1, OffsetFreq, ThreshXHigh, ThreshXLow, PciConflictAlmSwitch
o
tMobilityFromEutraCCO
o
o
INTEGRITY
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ulChBw, redBwMaxRbDl 10 to 15 PRBs Maximum number of PRBs assigned in downlink,
tPeriodicBsr 20 to 60s.
Throughput depends upon
o Channel environment (e.g. stationary or mobile, speed) and fading conditions.
o Reception conditions impaired by traffic load levels, and by interference between the cells, in short by
the user's SINR.
o Network layout, type of antenna.
o Position of users in the cell (implies e.g. path loss and fading).
o Restriction of user data rates (e.g. by terminal category)
o Link sharing weights (Quality of Service (QoS) configuration)
o Backhaul capacity
o Troubleshoot Throughput
 Check alarms
 Check UE capability
 Check AMBR of user service
 Check parameters like dlChannelBandwidth/ redBwMaxRbDl noOfUsedTxAntennas,
pZeroNominalPucch, noOfUsedTxAntennas
 Check Licenses 64-QAM
 Check Radio IE CQI, MCS, PRBs, Transmission mode,RI, HARQ, RLC retransmisssions,
CFI, buffer status, PHR, rxPowerReport, TTI scheduling, RLC discards, tStatusProhibit
 Check reports from L1 to MAC
 Check UE variables, ARP,buffer status, PHR report of UE, interference, pZeroNominalPusch
of neighbours/serving, Max PRBs allowed
 Check PDCCH, if CCE are occupied by donwlink grants than UL grants cannot be scheduled
 QoS profile QCI, priority bit, AMBR, ARP
 Transport Network
1. GE link counters (packet delays, errors, re-trans),SCTP, synch, IpInterface
2. Use wireshark (throughput result and signalling analysis)
Service Downlink Average Throughput
Service Uplink Average Throughput
AQM (automated queue management)-discard large data volume, relieves queue congestion, reduce
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transmission delay
ROHC (Robust Header Compression)
Traffic Volume, no of RBs, MCS coding, usage of PRB (Physical resource blocks), MAC retransmission, no
of users/edge users
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CQI 0 to 15, MCS 0 to 31, QC1 (highest) to QC9, RANK 1 to 4, modulation scheme
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RRM, Dynamic Resource Allocation = Scheduling, resources modified are PRBs, Power, PDCCH/PUCCH
Resources, TX rank, baseband power, UlBasebandCapacity DlBasebandCapacity
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Common Low Data Rate Issues: TCP/UPD/IP Config, transport network, cable swaps, pmIfInOctetsLink1Hi,
CRC errors, RxPower at eNB, GINR on DL, TA, sync
•
isLargePdcpSduAllowed, maxNbOfCallCapacityLicensing, sRPeriodicity 10 to 5ms,
numberOfPRBsForDynamicallyScheduledPUSCHForCentralRegion 16 to 20,
srsBandwidthConfiguration, dlBasicSchedulingMode, dlResourceAllocationType,
dlSchedulerMode, expectedNumberOfUEPerTTIForDLRR, maxNumberOfRBsPerUE,
nbrUserThrFDS, maximumFSSUsers, operationalMode, pmcMaxResultStringBlockSize,
mIMOMode
•
Reducing Low CINR impact
o Resource Block Group Assignments
o Frequency Selective Scheduling
o Inter-Cell Interference Coordination (ICIC)
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KPITYPE (alarm)
Power is distributed along subcarriers, high bandwidth  less power  less coverage
NAS authentication, service request, connection setup
MimoAdaptiveParaCfg (Transmission mode fixed 3/adaptive), ECGI, PCI, scheduling recources, LBBP
(baseband resources), Qam64Enabled, RachAlgoSwitch, AqmAlgoSwitch (queueing at the cost of integrity),
BfAlgoSwitch beamforming algo, DlSchSwitch, DlschStrategy (DLSCH_PRI_TYPE_RR(RR) to
DLSCH_PRI_TYPE_MAX_CI(MAX C/I)), UlSchSwitch, BtServiceWeight, PdcchSymNumSwitch,
MaxReportCellNum, measBdw, dlTrmBw, ulTrmBw, drbPrioDl, packLoss, resType, ulsBSD, ulsPrio, prio,
resType, raLargeMcsUl, PucchRS, dSrTransMax, deltaPreMsg3, deltaTfEnabled, dl64QamEnable,
dlCellPwrRed, dlChBw, dlMimoMode, dlRBM, harqMaxTrDl, hopBwPusch, hopModePusch, iniMcsDl,
iniPrbsUl, maxBitrateDl, maxNumAUeHo, maxNumUeDl, mbrSelector, mimoOlCqiThD, minBitrateDl, pMax,
redBwEnDl, redBwMaxRbDl, redBwRpaEnUl, riEnable, ulChBw, ulTargetBler, ulamcEdgFugEn,
ulamcSwitchPer, ulatbEnable, trafficType, rtoMax, qQualMinUtra, qRxLevMinUtra, proportional fair
scheduler, Preamble format affects UL throughput, Traffic Marking (transport), PRB, PDSCH power boosting
More users service fair  bit rate,
Less users  resource fair
spatial multiplexing and transmit diversity
Adaptive Transmission bandwidth ulatbEventPer
preamble sequence subset  uplink resources
MIMO featureStateDualAntDlPerfPkg, noOfTxAntennas
The resources managed by the downlink scheduler are downlink Physical Resource Blocks, downlink power,
PDCCH capacity and base-band processing capability. The resources managed by the uplink scheduler are
block resources for PUSCH, PDCCH, PHICH and base-band processing capacity.
100 simultaneous UEs, 8 DRBs max per User, licenseCapacityConnectedUsers,
licenseCapacityDlBbCapacity,, number of OFDM symbols for PDCCH
PUCCH Overdimensioning feature for Rural sites
DRX introduces extra delay to scheduling EnterDrxSwitch, DrxInactivityTimer, DrxReTxTimer,
ShortDrxCycle, FddEnterDrxThd, TrmSwitch, DiscardTimer, UeMaxRetxThreshold,
ENodeBMaxRetxThreshold, UlschPriorityFactor, DlMinGbr, PreAllocationWeight, PrioritisedBitRate,
LogicalChannelPriority, SriPeriod, UlschPriorityFactor, defPagCyc
noOfPucchSrUsers 50, nrOfSymbolsPdcch 1, allowedMeasBandwidth, channelBandwidth,
noOfPucchSrUsers, noOfRxAntennas, priority, pucchOverdimensioning 0, schedulingStrategy (round robin to
strict priority), ulChannelBandwidth, ulMinBitRate, pdb, dscp, dlMinBitRate, resourceAllocationStrategy,
dlChannelBandwidth, dlTransNwBandwidth, dlFrequencyAllocationProportion, ulTransNwBandwidth,
dlMaxRetxThreshold, mtu, tPollRetransmitDl, rlcMode, dlPollPDU, tReorderingDl, ulMaxRetxThreshold,
ulPollPDU, dlMaxHARQTx, priority bit
o Poor Uplink P0NominalPUSCH -67 to -58 uplink thorughput at the cost of network performance
o Increase PreambInitRcvTargetPwr, PwrRampingStep improved accessibility and throughput
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PLANNING
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LINK BUDGET TX Diversity of MIMO, Adaptive array gain, occupied sub-carrier bandwidth, RX diversity
Gain, Maximal Ratio Combining (MRC Gain)-requires two antennas and software in UE, HARQ Gains
Propagation Models Hata upto 1Ghz, Cost-Hata 2Ghz, Greenstien 2 Ghz, Ray Tracing (Dense Urban).
Propagation related parameters mean frequency dependent parameters, LTE is interference limited, System
gain, also known as the maximum allowable pathloss, use fixed interference/load margin or Monte Carlo
simulation
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LTE network poses also similar effects such as network breathing due to UL interference and cell range
dependency upon user data rate. PRACH planning is done in LTE. COST model is used by Nokia. Low Tx
power for small bandwidth, high Tx power for large bandwidth.
Ray Trace model for URBAN with vectors provided
LTE network poses also similar effects such as network breathing due to UL interference and cell range
dependency upon user data rate
DL load as % of total capacity, UL load in terms of interference margin
MAPL  Signal Strength threshold of Coverage based planning
Best server areas should be contiguous and should not be fragmented.
F 5 to 20Mhz  RSRP reduce and RSRQ increases with RSSI being constant
SON
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Self Healing, Optimization, configuration
Coverage and capacity optimization
MimoAdaptiveSwitch
DefDopplerLevel affects all KPIs
Energy Savings
Load generator ailgActive, dlPrbLoadLevel, trafficModelPrb
Interference Reduction, Interference Rejection Combining (IRC)
Beamforming
Automated Configuration of Physical Cell Identity
Mobility robustness optimisation
Mobility Load balancing optimisation
Random Access Channel Optimisation
Automatic Neighbour Relation Function
ROHC compression feature
CounterCheckTimer, CounterCheckTimer
Inter-cell Interference Coordination over X2 interface, ReportInterval, MaxReportCellNum, ReportAmount,
TriggerQuantity, Hysteresis, TimeToTrigger, A3Offset
· neighbour cell list optimization
· interference control
· handover parameter optimization
· Quality of Service related parameter optimization
· load balancing
· RACH load optimization
· optimization of home base stations
Adaptive Transmission bandwidth
FTP and HTTP are sensitive to end-to-end delay
Access Stratum b/w UE and eNodeB via RRC
– RRC idle
– RRC connected
Non Access Stratum procedure consists of attach, detach, tracking area update, service request, and
extended service request.
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EMM-DEREGISTERED:
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EMM-REGISTERED: MME establishes and stores the UE context
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ECM-IDLE:
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ECM-CONNECTED: S1 connection is established,
3GPP causes ref 24.301
Random Access Radio Network Temporary Identifier (RA-RNTI)
Subscriber/Cell/Interface/Cell traffic/terminal/traces
ROHC (Robust header compression)
PORTS and TRACE rbsUeTraceEventStreamingPort streamPortPmUeTrace streamStatusPmCellTrace
streamStatusPmUeTrace
Internet Protocol
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A class Subnet mask 255.0.0.0/8, less networks (inter) but more Host (intra)
B class Subnet mask 255.255.0.0/16
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C class Subnet mask 255.255.255.0/24, 255=network address, 0=host address, more networks (inter) but
less Hosts (intra)
Default gateway (eNodeB IP address): 169.254.1.10
Ping command, tracert, sniffer capture, show route
SCTP is use for signaling e.g NBAP
X2 and S1 are using GPRS Tunneling Protocol for User data (GTP-U) to transfer the user plane traffic.
ICMP reports erros of IP e.g ping, arp
The process of finding the new next hop after the network changes is called convergence
169.254.x.x IP addresses are self-assigned when your computer can't get an address any other way. It's an
almost sure sign of a problem
The Domain Name System (DNS) is used by RBSs to translate host names of other nodes (for example
RBSs, MMEs, synchronization servers) to IP addresses
Registered State
o PDN,TAU update
– IDLE state
o No NAS signaling b/w UE and network
– CONNECTED state:
o RRC b/w UE and eNodeB
o S1 b/w UE and MME
Ericsson tools
– CCR, Nexplorer, Auto-integration, TRUC, LTE troubleshooting WIKI, Moshell/BB/RU commands,
– Moshell, ITK,FlowFox,LTEDecoder,TeRouter/TeViewer,Multimon,uetrace,Japy,scheduling_parser,CDA
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Web,Hammerhead Web,LTELogTool,TET.pl,decode,LTE Trace Tools, UE Trace Recording (UETR)
Cell Trace Recording (CTR), mtd-signal trace
COMMAND LINE MP, RU, Moshell, RRU, BB, AMOS, BCM
TRACES CPP, baseband LPP, MTD, RDR, RRT, RBS, UE, T&E, HiCap, UE, Cell, CEX, NSD
LTE torubleshooting wiki
DUMP configuration report, Dumpcap (network traffic)
SYSTEM CRASH DUMPS baseband core, Post Mortem.
LOGS alarm, availability, HW, audit, trace&error, autointegration, board error, event, system, upgrade trace,
security, exceptions, trace-error, dump network traffic
EVENTS RB&UE Trace, EHB, exceptions
Ericsson Network IQ Reports
COLI, NCLI,OSS-RC, MicroCPP, ANR, equinox
PM-initiated UE Measurements
Layer 3 and S1/X2 (Flowfox, LTEDecoder, scripts), LTELogtool
LLDM for data rate diagnosis
Cell Traces are streamed using TCP while UE Traces are streamed using UDP, Iperf, TCP Optimizer,
Filezilla (FTP), VLC (Streaming/media), Neoload (Web browsing), wireshark, Element Manager,
AMOS,Netpersec(realtime thorughput), Iperf(inject TCP/UDP packets)
Iperf generates TCP/UDP traffic
Netpersec monitor thorughput
MMR = Channel Feedback Report (CFR)
Nethawk, wireshark (open source), TCP dump, Agilent
Cell Trace files .ROP
– te e all Ft_RRC_ASN
– te e all Ft_S1AP_ASN
– te e all Ft_X2AP_ASN
– te e all Ft_LTE_EXCEPTION
– te e all LTE_EXCEPTION
– te e all CELL_CONFIG
– te e all Ft_RRC_CONN_SETUP
– te e all Ft_ANR_COMMON
ENIQ ericssons’ tool like Optima
Moshell commands
– Teviewer
to view trace commands
– Te
enable trace
– Pset
UETR trace
–
Diff
for parameter audit of RNC.zip
Moshell rnc7
– momd . power|pwr
//list power control parameters
– set
primarycpichpower
– pmr
get specific KPI
– pmom
get counter
– lgx, lgo
alarm
– inv
check licenses
– KO
UE capability
– Te e
get QCI, AMBR, ARP values
COLI commands are for trouble shooting
L12 features, RoHC, 4-way receive diversity, service based HO, System info-9 tunneling, preempt low priority
users, oscillating HO minimization
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NSN tools
– TTI Trace, Emil, LTE browser, BTS-Log, RF Unit console, Memory Dumper
KPIs
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Delay
Delay Variation
Latency, throughput, packet drop, Packet Loss
Availability
Service Access time is a Latency KPI
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Event A1:
Serving becomes better than absolute threshold;
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Event A2:
Serving becomes worse than absolute threshold;
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Event A3:
Neighbor becomes amount of offset better than serving;
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Event A4:
Neighbor becomes better than absolute threshold; Inter-Freq
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Event A5:
Serving becomes worse than absolute threshold1 AND Neighbor becomes better
than another absolute threshold2.
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Event B1
Inter-RAT neighbor becomes better than threshold
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Event B2
threshold
Inter-RAT neighbor becomes better than threshold and serving becomes worse than
•
The RRCConnectionReconfiguration message is the command to modify an RRC connection. It may
convey information for measurement configuration, mobility control, radio resource configuration
(including RBs, MAC main configuration and physical channel configuration) including any
associated dedicated NAS information and security configuration.
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PDCP: integrity protection and ciphering;
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RLC: reliable and in-sequence transfer of information
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RSSI = wideband power= noise + serving cell power + interference power
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RSRP (dBm)= RSSI (dBm) -10*log (12*N), high BW  less RSRP
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
Value 00 (-140) to 97 (-44), step 1

Independent of load
RSRQ = N x RSRP / RSSI, high BW

Value 00 (-19.5) to Value 34 (-3), step .5

Dependent on load
•
RSRQ -3 to -19, RSRP -140 to -44
o
RSRQ=RSRP/(RSSI/N) = RSRP*N/(IN_n + ρ*12*N*Psc) and
o
SINR=S/(IN_m)
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SNR -15 to 40
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CINR=RSRQ
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UE estimates SINR based on the Power Spectral Density of the downlink RS and PSD offset
between PDSCH and RS. The SINR is Channel Quality Indicator (CQI).
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UE will report lower CQI values when using MIMO as opposed to SIMO in same RF environment
(SINR), UE will typically use lower Modulation/MCS
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CQI 0 to 15, MCS 0 to 28
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CINR -25 to 40dB
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RSRP -150 to -30
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RSSI -120 to 0
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UE PRACH TX Power -10 to 23 dBm
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RSRQ 0 to -40
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BLER 0 to 100% tolerable till 10%
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FER 0 to 100%
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UE categories 1(low) to highest(5)
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Transmission modes Mode 1 to 9 (highest), open/closed loop, antenna ports, MIMO (tm3) vs. TxD
(tm2) vs. SIMO (tm1)
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GINR Gain to interference and Noise Ratio
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A UE is said to be ‘in session’ if any data on a DRB (UL or DL) has been transferred during the last
100 ms
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PHR (power headroom report).
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PSD  SINR CQI Channel Feedback Report (CFR) transport format. RI i suded with MIMO
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link quality (SINR, BLER, HARQ OPP) MCS and coding rate TBS
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eNodeB Hardware
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D2U V2 (1 uCCM + 3 eCEM)
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TRDU (remote-radio-heads comprising of amplifiers and filters), 40W Tx power
DT Performance Metrics
• Air Interface
o UE Tx power
o RSSI
o SINR
o BLER
o Retransmission statistics (HARQ and RLC)
o Transport Format
o Number of resource blocks (DL/UL)
o Channel rank statistics
o MIMO mode (Tx diversity or Spatial Multiplexing)
o Serving sector
o Location (GPS)
o UE Velocity
• Throughput
o Individual user throughput and aggregated sector throughput
o UDP individual user throughput and aggregated sector throughput
o TCP individual user throughput and aggregated sector throughput
o User statistics (peak rates, average rates, standard deviations)
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Latency
o U-plane latency
o Connection set up times
o Handover interruption time within the same site and across different sites
Open loop PC is based on path loss, broadcasted/RRC parameters
Closed Loop PC is based on UL level and quality measurements
The power per subcarrier will be higher in smaller bandwidths  downlink coverage will be higher for
smaller bandwidths than for larger ones
Downlink AMC/fast AMC, SINR CQI  modulation and coding scheme, per TTI, scheduling,
Uplink AMC/ slow AMC, SRS, BLER  modulation and coding scheme, scheduling, Emergency
Downgrade, Fast Upgrade’
Current BLER and Target BLER CQI offset
PESQ 4 (best) to 1(worst)
SFN=system frame numer, 10ms, 0 to 1024
Sub-frame number, 1ms, 0 to 9
Paging Occasion = System and sub frame number
SFNmode 4  40 ms
THE UE reads P-SS and S-SS every 5ms to stay in synch. If UE successfully detected Cell ID/PCI, it
means UE successfully completed the time-sync.
Network not detected but signal bars are there RACH error
There are 64 PRACH sequences. Same PRACH preamble from multiple UE reaches the NW at the
same time. This kind of PRACH collision is called "Contention"
Preamble format 0-4
Precoding matrix 0-3. Related to MIMO
PDCCH format 0-3
Failure to decode SIB2 by the UE, will affect PRACH process
PMI precoding matrix indication, (codebook index,no.of layers) Table 6.3.4.2.3-2, 36.211, reported in
case of TM=4
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Transmission mode 1-7
PDCCH format 0(1)-3(8 CCEs)
T is the DRX cycle or defaultPagingCycle
QCI 1(Highest) to 9(Lowest)
RRC Connection Reconfiguration for measurement configuration, handover/mobility control, radio
resource configuration (RBs, MAC, physical channel), dedicated NAS information and security
configuration
RACH procedure initial access, handover, RRC recon estb, Sync loss in RRC connected mode
RBs/BW 25/5Mhz, 50/10, 75/15, 100/20
RRS Re-estb after UE tirggered RF failure, HO failure, RRC re-config failure
For RSRP: RSRP based threshold for event evaluation. The actual value is IE value – 140 dBm.
For RSRQ: RSRQ based threshold for event evaluation. The actual value is (IE value – 40)/2 dB.
RSRQ_00 = RSRQ < -19.5, RSRQ_34= -3 ≤ RSRQ 36.133
PH Power headroom , is defined as the difference between the nominal UE maximum transmit power
and the estimated power for PUSCH transmission PH_0= -23 ≤ PH < -22 & PH_62 = 39 ≤ PH < 40.
Low value index means UE has limited power. To transmit more PRBs, more power is required
EMM = EPS mobility management, timers ref: 10.2, 24.301
ESM = EPS session management, bearer assignment, timers ref: 10.3, 24.301
TA 0,1(156m) ,………1282 (200km)
RRC function SIB, RRC, connection, handover, paging, security message, NAS messages,
selection/reselection
CFI no. of scheduling bits, (number of OFDM symbols for PDCCH) vs. MCS vs. % scheduling HARQ
TM Transmission mode 1-7, 7.2.3-0 36.213
CQI 0 to 15, MCS 0 to 31, QC1 to QC9, RANK 1 to 4
♦
WCQI, wide-band CQI reported periodically
♦ SCQI, sub-band CQI, reported aperiodically on request from enodeb, 1(worst) to
7(best)
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RI Rank indicator, UE reports that info has been decoded from how many antennas, 2/4 layer spatial
multiplexing 7.2.3-1 36.213,
Assignable bits means the amount of data in the downlink buffer available for the scheduler to
schedule for this UE.
RLC DISCARDs will trigger TCP congestion control and lower throughput
BSR buffer status report 0(0KB) to 64 (15KB), power headroom report
Interference power > -104dBm
Link adaptation considers PHR, recived power of UE and UL interference power
QoS profile QCI, priority bit, AMBR, ARP
DSCP differentiated servise code point. QCI is mapped to DSCP
GTPU, GPRS tunneling protocol
DCI Downlink scheduling control indicator, channel coding formats, which resource block carries
your data, power control, transport format,HARQ, L1 signaling, DCI format 1, 1A, 1B, 1C, 1D, 2 or 2A
UCI Uplink scheduling control indicator, it contains, SR, Ack/Nack, CQI. Transmistted in PUSCH is
there is data and on PUCCH otherwise.
Resource Indication Value (RIV),that informs the device which RB to use and which start offset to
apply.
Hopping bits are
 Type1 00,01,10, follows one pattern only
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Type2 11 random based on subband, offset and mirror function. Unique to the cell
PDCCH format 0(low capacity) to 3(high signaling capacity)
DL Scheduling of RBs is determined TYPE & DCI format
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TYPE 0 to 2
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DCI format 0,1A,1B,1C,2,3,3A
RB assignment is carried in RIV (resource indication value)
RB= 1 slot x 12 carriers, resource block
RGB = 4 RBs or 48 carriers
If 20Mhz, 100 RBs and 25 RGBs
RGB subset 0,1,2,3
1 RE = 1 carrier x symbol
I REG=4 RE
e.g. 1CCE = 9 REGs or 36 REs, 72 bits if REG-8bits
1, 2, 4 or 8 CCE(s) (1 CCE = 9 REGs = 9*4 REs = 72 bits
Aggregation Level - a group of 'L' CCEs. (L can be 1,2,4,8)
In order to get the assigned RB resources (and the location) in PDSCH, DCI bits and format TYPE
has to be decoded
29 MSC schemes sector capacity is approximated by the harmonic mean of the MPR distribution
LTE smart antenna arrays focuses the beam towards the user
ARP allocation and retention priority. This determines if bearer can be dropped if congestions occurs,
or it cause other bearers to be dropped
C-RNTI, P-RNTI (Paging UE identifier), RA-RNTI(RACH), SI-RNTI(System information)
TPC 0(-6dB) to 7(8dB)  DCI format0/3
PUSCH channel TPC 0(-4dB) to 3(4dB)  DCI format0/3 + TPC-PUSCH-C-RNTI
PUCCH channel TPC 0(-1dB) to 3(3dB)  DCI format0/3 + TPC-PUSCH-C-RNTI
PDSCH Power is determined in the following manner
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If RS is not present in the RB of PDSCH, offset from RS power is defined by Pa, which is UE
specific offset. Pa is signaled by higher layers and is changes every 1ms, values are -6 to 3
dB.
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If RS is present then Pb and antennaPortsCount together will determine the offset. It is cell
specific and changes only when there is change in system message e.g if
antennaPortsCount=1 and Pb=2 then Offset = -2.218
Tranmist diversity same stream sent on diff antennas
Spatial diversity means diff stream on diff antennas
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Cyclic Delay Diversity (CDD) Addition of antenna specific cyclic shifts
Fast Power control is per slot
Pcmax = min(p-Max,Pumax), Pcmax is max UE power
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p-Max 23 dBm
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PuMax
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additionalSpectrumEmission =1 them MPR =0dB
RIV resource indication values indicates the starting position and number of RBs assigned. It is given
in DCI-0
Assigned PRBs in layer3
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MPR (max power reduction) table 6.2.4-1 36.101
In order to save signaling bits on the downlink control channel (physical downlink control
channel, PDCCH), these two parameters are not explicitly signaled. Instead, a resource
indication value (RIV) is derived which is signaled in the downlink control information on the
PDCCH.
Alpha range 0,0.4,0.5,0.6,0.7,0.8,0.9,1.0. It is used as path loss compensation factor as a trade-off
between total uplink capacity and cell edge-data rate. Higher value will be good for cell edge user but
not for the overall capacity due to high uplink power
Short and Long DRX cycles are configured to trade off battery saving and latency
PBR prioritized bit rate
timeAlignmentTimer
RBG a group of radio bearer with similar QoS requirements
SRS uplink scheduling, BSR, PHR. SRS is uplink counterpart of CQI report for downlink scheduling
Cylic shifts and sub-carrier offsets and used to define transmission combs for UEs or in other words
schedule reference signals of UE, cell edge user cannot use
srs-BandwidthConfig range 0(high bw) to 7 (Low bw)
srs-Bandwidth range 0 (whole band) to 3 narrowest band
Scheduling techniques
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In dynamic scheduling, the resources are distributed in 1 ms intervals. Quick link adaptation
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In persistent scheduling, longer transmission period is allocated for user with the one grant.
Poor link adaptation, fixed resources TB
RB Power is the power of 1 RB
TX Power is the power of all assigned RBs
TTI is subframe=1msec
A cyclic shift in the time domain (post IFFT in the OFDM modulation) is equivalent to a phase rotation
in the frequency domain (pre-IFFT in the OFDM modulation).
Common SRS is also called Cell Specific SRS and Dedicated SRS is also called UE Specific SRS.
MAC CE, MAC control info
1 PDCCH = 8 DCIs
PDCCH
 Carries common control info RACH response, Broadcast, SIB, paging, UL TPC
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Dedicated control info
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Uplink scheduling information (DCI format 0)
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Downlink scheduling information (DCI format 1/1A/1B/2/2A)
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PUSCH/PUCCH TPC commands (DCI format 3/3A)
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CASES
• Difference betwwen RRC or RAB congestion
• PRACH, not observable from TEMS. Check RF conditions, RACH parameters
• T304 Intra-LTE Hanodver failure
• TAC/LAC update
• CFI no. of scheduling bits, (number of OFDM symbols for PDCCH) vs. MCS vs. % scheduling
HARQ, CFI= 3 for 1.4, 3 and 5 MHz system bandwidths and CFI= 2 for 10, 15 and 20 MHz system
bandwidths
• Throughput was low because of low BSR and PHR
• No PHR left in the UE
Questions?
• Sounding reports
• SRS
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MAC layer
o MACContentionTimer
o TATimerLength
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