|
|
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 |
|||
|
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
- SON
- 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)
