MixNewsDotCom: LTE Optimization

Configuration	(FDD)Frame Type 1	(TDD) Frame Type 2
Frame Length	10 ms	10 ms
Subframes per Frame	10	10
Subframe Length (ms)	1	1
Slots per Subframe	2	2
Symbols/Slot, normal CP	7	7
Symbols/Slot, extended CP	6	6

What is Difference between MIB and SIB?

MIB and SIM are two types of System Information (SI) that is broadcasted in the serving are of particular cell. SI is carried by the logical channel BCCH, which in turn is carried by either of the transport channels BCH or DL-SCH.
Master information Block (MIB): is a static part of SI and contain information like number of antennas, system bandwidth,PHICH configuration, transmitted power and scheduling information on how the SIBs are scheduled together with other data on DL-SCH. MIB is transmitted on the BBCH–> PBCH with periodicity of every 40 ms.
System Information Block (SIB): is a dynamic part of SI. It carry relevant information for the UE, which helps UE to access a cell, perform cell re-selection, information related to INTRA-frequency, INTER-frequency and INTER-RAT cell selections. It is mapped on DL-SCH –>PDSCH with periodicity of every 80 ms, 160ms or 320ms for SIB1,SIB2 and SIB3 respectively.

How many types of SIBs are available in LTE?

There are 13 types of SIBs for LTE.
What does SIB1/SIB2/ … /SIB13 do?
Each SIB carry information related to specific tasks.

SIB-1	Carries Cell access related parameters like cell ID, MCC, MNC, TAC, scheduling of other SIBs
SIB-2	Carries Common and shared channel configuration, RACH related configuration are present; RRC, uplink power control, preamble power ramping, uplink Cyclic Prefix Length, sub-frame hopping, uplink EARFCN
SIB-3	Parameters required for intra-frequency, inter-frequency and I-RAT cell re-selections
SIB-4	Information regarding INTRA-frequency neighboring cells (E-UTRA) carries serving cell and neighbor cell frequencies required for cell reselection as well handover
SIB-5	Information regarding INTER-frequency neighboring cells (E-UTRA); carries E-UTRA LTE frequencies, other neighbor cell frequencies from other RATs.
SIB-6	Information for re-selection to INTER-RAT (UTRAN cells)
SIB-7	Information for re-selection to INTER-RAT (GERAN cells)
SIB-8	Information for re-selection to INTER-RAT (CDMA2000)
SIB-9	Information related to Home eNodeB (FEMTOCELL)
SIB-10	ETWS (Earthquake and Tsunami Warning System) information (Primary notification)
SIB-11	ETWS (Earthquake and Tsunami Warning System) information (Secondary notification)
SIB-12	Commercial Mobile Alert Service (CMAS) information.
SIB-13	Contains the information required to acquire the MBMS control information associated with one or more MBSFN areas.

On which channels SIBs are transmitted?

BCCH–> DL-SCH–> PDSCH.

Which SIBs are essential?

In LTE, for a UE to access the eNB, at the most minimum 2 SIBs are required (SIB1 and SIB2). Information regarding SIB2-SIB13 are carried in SI messages and are included in schedulingInfoList which is part of SIB1.

Why we need SIB19?

SIB 19 is needed when UE is coming back from 3G to 4G. LTE priority should be set high in 3G. SIB19 carries the absolute priority of the serving UMTS cell, the absolute priorities of the LTE frequencies, and the cell reselection thresholds.

How can we calculate LTE DL/UL throughput?

Note: Please see tables in Q.1 and Q.3 for relevant info provided in below answer.

Lets’ assume we have 20 MHz channel bandwidth.
we need to calculate the resource elements in a subframe for this band i.e.

12subcarriers x 7 OFDMA symbols x 100 resource blocks x 2 slots= 16800 REs per subframe.

Assume we have 64 QAM modulation and no coding, one modulation symbol will carry 6 bits.

16800 modulation symbols x 6 bits / modulation symbol = 100800 bits.
So, the data rate is 100800 bits / 1 ms = 100.8 Mbps.

With 4×4 MIMO, the peak data rate goes up to 100.8 Mbps x 4 = 403 Mbps.
Estimate about 25% overhead e.g. PDCCH, reference signal, sync signals, PBCH, and some We get 403 Mbps x 0.75 = 302 Mbps.

What is SON & how does it work in LTE?

Self-configuring, self-optimizing wireless networks is not a new concept but as the mobilenetworks are evolving towards 4G LTE networks, introduction of self configuring and self optimizing mechanisms is needed to minimize operational efforts. A self optimizing functionwould increase network performance and quality reacting to dynamic processes in the network.This would minimize the life cycle cost of running a network by eliminating manualconfiguration of equipment at the time of deployment, right through to dynamically optimizingradio network performance during operation. Ultimately it will reduce the unit cost and retailprice of wireless data services.See Self-configuring and self-optimizing Networksin LTE for details.

How does Timing Advance (TA) works in LTE?

In LTE, when UE wish to establish RRC connection with eNB, it transmits a Random AccessPreamble, eNB estimates the transmission timing of the terminal based on this. Now eNBtransmits a Random Access Response which consists of timing advance command, based onthat UE adjusts the terminal transmit timing.The timing advance is initiated from E-UTRAN with MAC message that implies and adjustmentof the timing advance.See Timing Advance (TA) in LTE for further details.

How does LTE UE positioning works in E-UTRAN?

UE Positioning function is required to provide the mechanisms to support or assist thecalculation of the geographical position of a UE. UE position knowledge can be used, forexample, in support of Radio Resource Management functions, as well as location-basedservices for operators, subscribers, and third-party service providers.See LTE UE positioning in E-UTRAN for more details.

How does Location Service (LCS) work in LTE network?

In the LCS architecture, an Evolved SMLC is directly attached to the MME. The objectives of thisevolution is to support location of an IMS emergency call, avoid impacts to a location sessiondue to an inter-eNodeB handover, make use of an Evolved and support Mobile originatedlocation request (MO-LR) and mobile terminated location request MT-LR services.Release 9 LCS solution introduces new interfaces in the EPC:

SLg between the GMLC and the MME

SLs between the E-SMLC and the MME

Diameter-based SLh between the HSS and the HGMLC

How does Lawful Interception works in LTE Evolved Packet System?

3GPP Evolved Packet System (EPS) provides IP based services. Hence, EPS is responsible only forIP layer interception of Content of Communication (CC) data. In addition to CC data, the LawfulInterception (LI) solution for EPS offers generation of Intercept Related Information (IRI) records from respective control plane (signalling) messages as well.See Lawful Interception Architecture for LTE Evolved Packet System for more details.

What is carrier aggregation in LTE-Advanced?

To meet LTE-Advanced requirements, support of wider transmission bandwidths is requiredthan the 20 MHz bandwidth specified in 3GPP Release 8/9. The preferred solution to this iscarrier aggregation.It is of the most distinct features of 4G LTE-Advanced. Carrier aggregation allows expansion of effective bandwidth delivered to a user terminal through concurrent utilization of radioresources across multiple carriers. Multiple component carriers are aggregated to form a largeroverall transmission bandwidth.

What is LTE Intra E-UTRAN Handover?

Intra E-UTRAN Handover is used to hand over a UE from a source eNodeB to a target eNodeBusing X2 when the MME is unchanged. In the scenario described here Serving GW is also unchanged. The presence of IP connectivity between the Serving GW and the source eNodeB, aswell as between the Serving GW and the target eNodeB is assumed.The intra E-UTRAN HO in RRC_CONNECTED state is UE assisted NW controlled HO, with HOpreparation signalling in E-UTRAN.To prepare the HO, the source eNB passes all necessary information to the target eNB (e.g. E-RAB attributes and RRC context) and UE accesses the target cell via RACH following acontention-free procedure using a dedicated RACH preamble.The HO procedure is performed without EPC involvement, i.e. preparation messages are directlyexchanged between the eNBs. The figure below shows the basic handover scenario whereneither MME nor Serving Gateway changes:

What RBS Hardware does Ericsson use for LTE Technology?

RBS 6000 series

What is considered a good RSRP and RSRQ threshold, good for LTE radio conditions?

RSRP = >-95 dBm (Planning with -113 dBm) RSRQ=<-7db span="">

What latency (RTT) have you experienced while pinging with 32 bytes?

40-200ms

What technology is used in the uplink and in the downlink?

Uplink: SCFDMA
Downlink: OFDMA

How many Transmission mode we have? What are they? How they are configured in moshell?

Transmission mode:

Single Input Multiple Output (SIMO)
Transmit Diversity
Open Loop Spatial Multiplexing (OLSM)

What other DT tool or any LTE tool have you ever used?

TEMS Discovery & Actix

What are the Radio Frame Structures Supported by LTE?

LTE Radio Frame:

Air Interface For 3G LTE.
Manage the different types of information that needs to be carried between the eNodeB and the User Equipment.
The frame structures for LTE differ between the Time Division Duplex, TDD and the Frequency Division Duplex, FDD
Two adjacent slots constitute a sub-frame of length 1 ms
There are two types of LTE frame structure:

Type 1: used for the LTE FDD mode systems.
Type 2: used for the LTE TDD systems

What is eNodeB Capacity?

eNodeB Capacity
Peak Bit Rate(Mbps)=bit per Hz x N subcarriers x N symbol per subframe in 1ms

Bandwidth (MHz)	Modulation
Bandwidth (MHz)	QPSK	16 QAM	64 QAM
1.4	2.016 Mbps	4.032 Mbps	6.048 Mbps
3	5.04 Mbps	10.08 Mbps	15.12 Mbps
5	8.4 Mbps	16.8 Mbps	25.2 Mbps
10	16.8 Mbps	33.6 Mbps	50.4 Mbps
15	25.2 Mbps	50.4 Mbps	75.6 Mbps
20	33.6 Mbps	67.2 Mbps	100.8 Mbps

Whats difference b/w video download and video streaming?

Streaming is playing audio/video content in real time through the Internet. This does not eat up any space on your computer’s hard drive.
A fast Internet connection is required to view the videos at its clearest because the video quality is dependent on the speed of your connection. If you experience frequent pauses or buffering on your viewing or if you’re not satisfied with the quality, consider downloading the clip (if possible).
Downloading is transferring data from a server into your own computer. You need to have sufficient hard drive space to be able to save the content.
Although downloading may take some time, the advantages are that you can watch the content anytime since it’s already saved in your computer and you don’t need to be connected to the Internet to watch the video. The video will also be of higher quality with no interruptions upon playback

IMPORTANT LTE OPTIMIZATION STEPS & TECHNIQUES

ACCESSIBILITY

IDLE

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

Reselection

Start Reselection

SIntraSearch 29*2=-58dBm to 31 will encourage reselection
sNonIntraSearch 2 to 5 will discourage IRAT reselection, -114+5*2=-104dBm
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
Cell offset qOffsetCellEUtran, qOffsetCell, qOffCell, interTResEut, qRxLevMinInterF, offsetFreq 2 to 0
CellReselPriority 0 to 2 for high priority, cellReselectionPriority 5 to 3 èdiscourage reselection, threshXHighHrpd, tReselectionEutra 2 to 4, tReselectionEutraSfHigh 3 to 2
NcellReselectionHigh 16 to 10 è 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

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 èless resources used but delay in access, maxCrSibDl, si4Periodicity

CellRadius

RRC setup success rate (service)

pZeroNominalPucch -117

RB=SRB+DRB

SRB0 is for RRC messages transmitted over the Common Control Channel CCCH
SRB1 is transmitted over the Dedicated Control Channel DCCH. RRC connection establishment is Signaling Radio Bearer-1. Theis is for NSN and RRC
SRB2: bearing NAS signaling and transmitted over the DCCH, This is for NAS and RRC of high priority
DRB bears data maximum of eight DRBs per UE with eNodeB
T302 4 to 6 s, timer b/w retries for RRC connection establishment
tlnactivityTimer

Causes emergency highPriorityAccess Mobile terminating Mobile Originating Signaling and mo-Data.
RRC failures 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
T311 10000 to 150000 ms, RRC reestablishment
T3446
T3460 supervises authentication request.NAS timer
T3470 sueprvises identity request. NAS timer
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)

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) è 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

Early contention resolution can improve the Access success rate
accessBarringTime s32 è T303
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.

Contention (preamble collision) initial RRC connection establishment, RRC connection reestablishment, uplink data arrival
Non Contention (preambles allocated) handover, downlink data arrival
BackOffSwitch adjust the back off time dynamically to relieve load on RACH
RACH process influences the call setup delay, handover delay, data resuming delay, call setup success rate and handover success rate.
AcBarringFactorForCall P95(95%) to 80 will discourage access

ATTACH

Incorrect LAC at MSC, TAC at MME

T3412 TAC update
T3414 UE attach with NAS
S1_implicitDetachTimer
S1_MobileReachableTimer

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

FACH
PAGING
Discarded Paging Messages over the Uu Interface, pagingDiscardTimer 3 to 5s, T3413, , DefaultPagingCycle or DRX cycle rf128 to fr64 è shorter paging cycle. AS (UE & eNodeB) RRC service request, location update, and paging, maxCrPgDl, maxNumRrc, pagingNb, raCrntiReuseT, modificationPeriodCoeff 2, rrcConnReestActive 0 to 1 è RRC success, cellRange 15 to 10Km è success, coverageIndicator, nrOfRrcConnectedReserved, dlGbrAdmThresh,
T=defaultpagingcycle 1T to 1/2T è less paging time, high paging traffic, fewer groups, more UEs in a group,
nB T to 1/4Tè fewer and larger groups, less paging capacity
T=defaultpagingcycle 1T to 2T è more paging time, low paging traffic, more groups, less UEs in a group,
Nb è ONET (1T) to TWOT(2T) more paging capacity
maxNoOfPagingRecords3 to 5 èmore UEs in a paging message
Single paging message can accommodate a maximum of 16 paging records. Small TA è more LAC updates and chances of missing paging message increase
pagingForceMCSmin -1 to 2 èmin MCS scheme
NAS (UE & MME) procedure consists of attach, detach, tracking area (TA) update, service request, and extended service request.
RRC connection reestablishment caused by handover failure, RRC reconfiguration failure, or radio link failure downlink data arrival. uplink data arrival.
initial coding is set by parameter
CCCH

SRB-0
RRC(SRB-1) over DCCH Connection Request (Over CCCH from UE to eNodeB) èUE context/SRB1 allocation è RRC Connection Setup (eNodeB to UE) è RRC Connection Setup Complete (UE to eNodeB) è Initial UE Message (eNodeB to MME) è Initial Context Setup message (MME to eNodeB) è Security Mode command (eNodeB to UE)èRRC Connection Reconfiguration message(eNodeB to UE)è RRC Connection Reconfiguration Complete message (UE to eNodeB)
RRC(SRB-2) for ERABover DCCH,

Signaling Link Release RRC Release UeInactiveTimer 1800 to 2000s, load rebalancing
ERAB Setup Success Rate (VoIP)
ERAB Setup Success Rate (All)

E-RAB establishment = Signaling Radio Bearer-2 (SRB2) establishment and Data Radio Bearer (DRB) establishment. ERAB=RB(Um)-S1(S1)

Radio Network Unavailability Rate
9 Radio Bearers RadioBeare rs _QCI _ 1 (highest) to 9

RRC reconfiguration establishment, modification and Release of RBs
SRB2 Inititial Context Setup Request (MME to eNodeB) è RRC connection reconfiguration (enodeB to UE)è RRC connection reconfiguration complete (UE to eNodeB) èIntial context setup (eNodeB to MME) èERAB setup request (MME to eNodeB) è RRC reconfiguration (enodeB to UE) è RRC reconfiguration complete (UE to eNodeB) è ERAB setup response (eNodeB to MME)
DRB ERAB modify request (MME to eNodeB) è RRC connection Reconfiguration (eNodeB to UE) è RRC Reconfiguration complete(UE to eNodeB) èERAB modify response(eNodeB to MME). 8 DRB max.

csFallbackPrio, s1RetryTimer, CS Fall-Back feature, GoldServiceArpThd 5 to 8 è access, Qci1HoThd 90 to 95 è access, NewGoldServiceOffset 10 to 5 è access to gold at the cost of silver/copper, a2TimeToTriggerRedirect, ocAcProbFac, acBarSig, sigAcProbFac, addAUeRrHo, qRxLevMinUtra
RAC is based on No. of RRCs and active users, maxNumActDrb
RRM, Dynamic Resource Allocation = Scheduling, resources modified are PRBs, Power, PDCCH/PUCCH Resources, TX rank, baseband power, UlBasebandCapacity DlBasebandCapacity
isRrcReEstablishmentAllowed
Channels

Downlink Control Channels

PCFICH (no of symbols in PDCCH depending upon signaling), maxNrSymPdcch,
PDCCH (scheduling, Downlink control info-DCI, MIMO mode, precoding, modulation, SIB, 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 è 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. srsBandwidth, srsHoppingBw, srsPwrOffset, nbrSRSperTTI
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) è high coverage/capacity but interference on others, PDSCH power boosting, initial coding is set by parameter
Paging initial coding is set by parameter

Uplink channels

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
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
PRACH Preambles, initial access, handover, UL sync and UL SCH resource requests. initial coding is set by parameter, NCS(prachCs)
DRS Demodulation reference signals for channel estimation
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
POWER CONTROL

FPC Fractional Power Control, applicable on Cell-specific reference signal, PBCH. estimation, and 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)è 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 è more interference but good accessibility, FilterRsrp
PDCCH Carrying RACH Response, Paging Messages, SIBs. RaRespPwr, PagingPwr -3171, DbchPwr, They affect accessibility. Increase in Power è more interference but good accessibility.
PDCCH (RRC or SD)PC is dynamic w.r.t SIR targets and Static based on PdcchPwrDedi larger value è 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 è 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

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) ègood for cell edge users but not of system performance, P0NominalPUSCH -67 to -58 large value è throughput of the cell increases but network decreases, DeltaMcsEnabled 0 to 1 è MCS value affects power control and throughput increases

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
primarySyncSignalPowerOffset
SRS for uplink channel estimation and uplink timing, PSRS OFFSET, low power è low performance
maximumTransmissionPower, confOutputPower, sectorPower, pMaxInterF,
RaRspPwr PchPwr DbchPwr SchPwr PbchPwr PcfichPwr PrsPwr
PaPcOff
Open loop PC is based on path loss, broadcasted/RRC parameters
Closed Loop PC is based on UL level and quality measurements, CELL_PWR_RED

LOAD CONTROL

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 è 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 è admission
GbrRbUseHighProportion, dlAccGbrAdmThresh

Load Balancing

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 èload control, imLoadBalancingActive, threshServingLowHystMin, threshXHighHystMin

Congestion Control

Preemption of GBR services with low energy efficiency rate (EER)

PreemptionArpThd 5 to 3 è congestion relief

GBR service rate downsizing

CopperGbrCongProportion 90% to reduction 80 reduction è congestion relief

Qci1CongThd 65 + CongRelOffset 20 < Qci1HoThd 90 to 85 è congestion relief? QcixHoThd is small èoverall 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 è efficiency

if ARP is >= LdcMeaArpThd 10 to 5 è EER is calculated
LdcMeaArpThd 10 to 13 è congestion relief but drops increase

RETAINBILITY-CDR

Call Drop Rate (VoIP)
Service Drop Rate (All)
Radio Network Unavailability Rate
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
CQI 0 to 15, MCS 0 to 31, QC1 to QC9, RANK 1 to 4
T310 indicates physical failure 200 to 300
UeInactiveTimer 1800 to 2000s
T321
Interference

IRC works at physical layer è MIMO
ICIC works at MAC layer, adjust center CCU and edge CEU UE loading
dlInterferenceManagementActive switch, noOfRxAntennas, tHODataFwdReordering 50 to 100 ms
tInactivityTimer, a5B2MobilityTimer, s1RetryTimer, tHODataFwdReordering, cellRange 15 to 10Km è low drops, coverageIndicator, ulInterferenceManagementActive, pMaxServingCell

MIMO

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 èrelease of the E-RAB had a negative impact on the end-user.

Voice release, normalized to releases
PS releases, normalized to session time

tlnactivityTimer
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 è 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

General Causes

Path imbalance, connectors, hardware, antenna tilt, serving/neighbor config, discontinuous coverage, parameter settings, interference, cell degraded, PCI collisions,unavailabilities, check equipment health,

T304 supervises the Intra-LTE HO
Events

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 è discourage HO, timeToTriggerA3 40 to 64, hysteresisA2Sec (neighbor) 10 to 20, hysteresisPm, reportAmountA2Prim 1 to 2 è 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

SON

AnrSwitch, MroSwitch, TpeSwitch
Power Control
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
Neighbor-ANR

maxReportCellsPm, measurementPriority, cellAddRankLimitEutran, isRemoveAllowed, 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% è 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 èhigh speed, FastAnrIntraRatMeasUeNum 5 to 7 will improve HOSR. Periodic measurements èincrease power and decrease throughput. FastAnrRsrpThd -102 to -90 è make ANR tough èURBAN
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 è SON or MRO
OptPeriod 1440 to 1300, OptParaThd 70 to 80% HOSRè SON

Ealry Hos>Delayed Hos è decrease CIO of neighbor

Detect early or late HO

IRAT HO a2ThresholdRsrpPrim, a2ThresholdRsrpSec, b2Threshold1Rsrp, Uemeasurementsactive, triggerQuantityA2Sec, hysteresisA2Prim, timeToTriggerA2Prim, isForcedDrxForCsFallbackAllowed no to yes, isX2LoadIndicationAllowed, threshold2EutraRsrq 8 (-7,-6.5) to 9 (-10,-9.5) è discourage A5, tReselectionEUTRAN, maxTimeAllowedForCsfbMobilityAttempt
a3offset 30 to 35 è discourage A3 or adding Intra freq neighbor, a1ThresholdRsrqPm
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.
Intra-frequency Handover Out Success Rate

Cell group ID is critical
In load based, CIO is changed automatically
A3 Mn + Ofn + Ocn – Hys > Ms + Ofs + Ocs + Off (IntraFreqHoA3Offset)

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 è cell selection procedure è RRC connection re-establishment

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
Inter-frequency Handover Out Success Rate

A2 Ms + Hys < Thresh

InterFreqHoA1A2Hyst 4 to 6(3dB), InterFreqHoA2ThdRSRQ -24(-12dB) to -28(-14dB),

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

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)

InterRatHoA2ThdRSRQ -20 to -22, InterRatHoA1ThdRSRQ -20 to -18, InterRATHoUtranB1ThdEcN0 -20 to -16, LdSvBasedHoGeranB1Thd -98 to -94, UtranFilterCoeffRSCP FC0 to FC2, InterRatHoRprtAmount, InterRatHoGeranRprtInterval

T311 10000 to 150000 ms
Inter-RAT Handover Out Success Rate (LTE to GSM)

GeranFilterCoeff FC0 to FC2
T304 ms4000 to ms8000
redirectionInfoRefPrio1, OffsetFreq, ThreshXHigh, ThreshXLow, PciConflictAlmSwitch
tMobilityFromEutraCCO

INTEGRITY

ulChBw, redBwMaxRbDl 10 to 15 PRBs Maximum number of PRBs assigned in downlink, tPeriodicBsr 20 to 60s.
Throughput depends upon

Channel environment (e.g. stationary or mobile, speed) and fading conditions.
Reception conditions impaired by traffic load levels, and by interference between the cells, in short by the user’s SINR.
Network layout, type of antenna.
Position of users in the cell (implies e.g. path loss and fading).
Restriction of user data rates (e.g. by terminal category)
Link sharing weights (Quality of Service (QoS) configuration)
Backhaul capacity
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

GE link counters (packet delays, errors, re-trans),SCTP, synch, IpInterface
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 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
CQI 0 to 15, MCS 0 to 31, QC1 (highest) to QC9, RANK 1 to 4, modulation scheme
RRM, Dynamic Resource Allocation = Scheduling, resources modified are PRBs, Power, PDCCH/PUCCH Resources, TX rank, baseband power, UlBasebandCapacity DlBasebandCapacity
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

Resource Block Group Assignments
Frequency Selective Scheduling
Inter-Cell Interference Coordination (ICIC)

KPITYPE (alarm)
Power is distributed along subcarriers, high bandwidth è less power è 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 èservice fair è bit rate,
Less users è resource fair
spatial multiplexing and transmit diversity
Adaptive Transmission bandwidth ulatbEventPer
preamble sequence subset è 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

Poor Uplink P0NominalPUSCH -67 to -58 uplink thorughput at the cost of network performance
Increase PreambInitRcvTargetPwr, PwrRampingStep èimproved accessibility and throughput

PLANNING

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
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 è Signal Strength threshold of Coverage based planning
Best server areas should be contiguous and should not be fragmented.
F 5 to 20Mhz è RSRP reduce and RSRQ increases with RSSI being constant

SON

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.

EMM-DEREGISTERED:
EMM-REGISTERED: MME establishes and stores the UE context
ECM-IDLE:
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

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
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
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

PDN,TAU update

IDLE state

No NAS signaling b/w UE and network

CONNECTED state:

RRC b/w UE and eNodeB
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 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

NSN tools

TTI Trace, Emil, LTE browser, BTS-Log, RF Unit console, Memory Dumper

KPIs

Delay
Delay Variation
Latency, throughput, packet drop, Packet Loss
Availability
Service Access time is a Latency KPI

Event A1: Serving becomes better than absolute threshold;
Event A2: Serving becomes worse than absolute threshold;
Event A3: Neighbor becomes amount of offset better than serving;
Event A4: Neighbor becomes better than absolute threshold; Inter-Freq
Event A5: Serving becomes worse than absolute threshold1 AND Neighbor becomes better than another absolute threshold2.
Event B1 Inter-RAT neighbor becomes better than threshold
Event B2 Inter-RAT neighbor becomes better than threshold and serving becomes worse than threshold

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.
PDCP: integrity protection and ciphering;
RLC: reliable and in-sequence transfer of information
RSSI = wideband power= noise + serving cell power + interference power
RSRP (dBm)= RSSI (dBm) -10*log (12*N), high BW è less RSRP

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

RSRQ=RSRP/(RSSI/N) = RSRP*N/(IN_n + ρ*12*N*Psc) and
SINR=S/(IN_m)

SNR -15 to 40
CINR=RSRQ
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).
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
CQI 0 to 15, MCS 0 to 28
CINR -25 to 40dB
RSRP -150 to -30
RSSI -120 to 0
UE PRACH TX Power -10 to 23 dBm
RSRQ 0 to -40
BLER 0 to 100% tolerable till 10%
FER 0 to 100%
UE categories 1(low) to highest(5)
Transmission modes Mode 1 to 9 (highest), open/closed loop, antenna ports, MIMO (tm3) vs. TxD (tm2) vs. SIMO (tm1)
GINR Gain to interference and Noise Ratio
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
PHR (power headroom report).
PSD è SINR èCQI Channel Feedback Report (CFR) ètransport format. RI i suded with MIMO
link quality (SINR, BLER, HARQ OPP)è MCS and coding rate èTBS

eNodeB Hardware

D2U V2 (1 uCCM + 3 eCEM)
TRDU (remote-radio-heads comprising of amplifiers and filters), 40W Tx power

DT Performance Metrics

Air Interface

UE Tx power
RSSI
SINR
BLER
Retransmission statistics (HARQ and RLC)
Transport Format
Number of resource blocks (DL/UL)
Channel rank statistics
MIMO mode (Tx diversity or Spatial Multiplexing)
Serving sector
Location (GPS)
UE Velocity

Throughput

Individual user throughput and aggregated sector throughput
UDP individual user throughput and aggregated sector throughput
TCP individual user throughput and aggregated sector throughput
User statistics (peak rates, average rates, standard deviations)

Latency

U-plane latency
Connection set up times
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 è downlink coverage will be higher for smaller bandwidths than for larger ones
Downlink AMC/fast AMC, SINRè CQI è modulation and coding scheme, per TTI, scheduling, Uplink AMC/ slow AMC, SRS, BLER è modulation and coding scheme, scheduling, Emergency Downgrade, Fast Upgrade’
Current BLER and Target BLERè 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 è 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 èRACH 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
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 < 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)

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
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

TYPE 0 to 2
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
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) è DCI format0/3
PUSCH channel TPC 0(-4dB) to 3(4dB) è DCI format0/3 + TPC-PUSCH-C-RNTI
PUCCH channel TPC 0(-1dB) to 3(3dB) è DCI format0/3 + TPC-PUSCH-C-RNTI
PDSCH Power is determined in the following manner

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.
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
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

p-Max 23 dBm
PuMax

MPR (max power reduction) table 6.2.4-1 36.101

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

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

In dynamic scheduling, the resources are distributed in 1 ms intervals. Quick link adaptation
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
Dedicated control info

Uplink scheduling information (DCI format 0)
Downlink scheduling information (DCI format 1/1A/1B/2/2A)
PUSCH/PUCCH TPC commands (DCI format 3/3A)

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Wednesday, May 13, 2020

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