LTE Principle and Optimization

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HUAWEI TECHNOLOGIES CO., LTD.

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

LTE Air Interface Physical Layer



LTE Cell acquisition and call setup



LTE Optimization



LTE KPI



LTE Feature

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HUAWEI TECHNOLOGIES CO., LTD. Page 3

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Radio Resource Control and Physical Layer

Parameter Value

Channel bandwidth (MHz) 1.4 3 5 10 15 20 Allocated resource blocks 6 15 25 50 75 100

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Downlink Physical Channels



PBCH (Physical Broadcast Channel) : MIB (Master Information Block): DL-Bandwidt

h (6, 15, 25, 50, 75, 100), PHICH Configuration (Ng and Normal/Extended), System Fra

me Number(SFN)



PCFICH (Physical Control Format Indicator Channel): Indicate OFDM symbol No ca

n be used for PDCCH in 1 subframe.



PDCCH (Physical Downlink Control Channel): UL/DL Scheduling information, UL po

wer control information.



PHICH (Physical Hybrid ARQ Indicator Channel): Feedback UL HARQ （ Hybrid Aut

omatic Repeat Request ） ACK/NACK

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Uplink Physical Channels



PRACH (Physical Random Access Channel)



PUCCH (Physical Uplink Control Channel)

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Downlink Channel/ Uplink Channel Mappin

g

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

LTE Air Interface Physical Layer



LTE Cell acquisition and call setup



LTE Optimization



LTE KPI



LTE Feature

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Cell Search Procedure

_PSS decodi ng • _{Slot synchronization} _SSS decod ing • _{Frame synchronization} • _{Obtain PCI} _RS meas urem ent • _RSRP/RSRQ _BCCH decod ing • _{MIB&SIB reception}

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Synchronization Signals

 UEs perform synchronization and obtain PCIs using synchronization signals.

 PCI = 3 x Physical cell group ID ( ) + Cell ID ( )

 Synchronization signals are classified into the primary synchronization signal (PSS) and seco

ndary synchronization signal (SSS).

 Position in the time and frequency domains:

 Time domain: The PSS and SSS have different positions in the time domain for LTE FDD and T

DD .

 Frequency domain: The PSS and SSS are located in the middle of the frequency domain.  Sequence:  PSS: Zadoff-Chu sequence  SSS: binary M-sequence (1) ID N N_ID(2)

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Functions of PSS and SSS



PSS

 Provides downlink synchronization information for UEs. Each PSS uses one of t

he three ZC sequence types, and different ZC sequences are used for neighbori ng cells or sectors.

 These three ZC sequences are mapped to three different Cell IDs.  Value range: 0,1,2



SSS

 Enables the UE to perform accurate synchronization and carries the physical ce

ll group ID.

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Synchronization Channel: Cell Search and Downlink Synchr

onization

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System Information Reception Process

 Why is the system information reception procedure required ?

 The UE configures each layer’s parameters based on the parameter settings in the system infor

mation received on the RRC layer before requesting network camping and admission.

 What information does the system information contain ?

 One master information block (MIB) and 13 system information blocks (SIBs), including UE para

meters set by the eNodeB.

 How is the system information

received ?

 The figure in the right shows

procedure the system information is received.

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MIB Mapping & Delivery



MIB introduction

 Carried by BCCH->BCH->PBCH

 Deliver very basic system information,

including system frame number, DL b andwidth and PHICH configuration

 Broadcast period: 40ms 1 2 3 4 5 6 0 1 2 3 4 5 6 Radio frame 40ms PBCH TTI 4 symbols MIB block Coded block SSS PSS PBCH

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SIB Mapping & Delivery



SIBs are mapping on BC

CH->DL-SCH-> PDSCH:

 SIB1 and SIB2 are mandat

ory, and others are option al.



Period of SIBs

 SIB1: 80ms

 From SIB2 to SIB8, SIB10

and SIB11: It is a flexible p eriod, with 80,160,320,12 80,2560 and 5120ms.

Type Contents

SIB1 Cell selection and camp related parameters ， SI period for other SIBs

SI

SIB2 Common physical channel configuration, UE timer, uplink _bandwidth SIB3 Common parameters for cell reselection

SIB4 Intra-frequency neighbor list; Neighbor reselection _{parameters; Neighbor black list}

SIB5

Inter-frequency list and corresponding cell reselection parameters

Inter-frequency neighbor list and corresponding cell reselection parameters

Inter-frequency black list SIB6 UMTS frequency list

SIB7 GSM frequency list

SIB8 CDMA2000 frequency list and neighbor list

SIB9 Home eNodeB information

SIB10 ETWS primary notification SIB11 ETWS secondary notification SIB12 CMAS notification

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System Message Tracing Cases

MIB MCC:460 MNC:01 Cell ID:7B8FF TAC:21

Cell is not barred

Intra-freq Reselection is allowed Other SIBs excluding SIB1 and SIB2 SIB1 SI

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Cell Selection Criteria

Criteria for cell selection: Srxlev

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Random Access Overview

 Purpose of random access

 Get uplink synchronization

 Acquire uplink scheduling resourc

e

 Scenarios:

 Case1: UE initial attach

 Case2: RRC reestablishment after

RRC drops

 Case3: Handover to a new cell  Case4: Downlink data arrival in eN

odeB when UL out-of-sync occurs

 Case5: Uplink data detected by UE

when UL out-of-sync occurs

 Case6: When UE trigger LCS(Locati

on service)

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 UE randomly selects a preamble

and sends it, conflict might occurs.

(Case1, Case2 and Case5)

Contention based

Non-contention based

 Before random access,

eNodeB assigns a dedicated preamble to UE, so there is no conflict.

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General Procedure of Attachment

 _Signaling connection setup  _{(RRC and S1} dedicated signaling)  _NAS procedure  _{(Authentication} & NAS security)  _{User plane} setup  _{(Default EPS} bearer setup)

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RRC Connection Establishment Process



During RRC connection setup,

SRB1

is set up.

 SRB 0 / CCCH / UL-SCH / PUSCH

 SRB 0 / CCCH / DL-SCH / PDSCH

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Relationship between Establishment Cause and NAS Proced

ure

NAS Procedure RRC Establishment Cause

Attach Attach 　 Mobile Originating Signaling/Delay Tolerant _{Access/Emergency}

Detach Detach Mobile Originating Signaling

Tracking Area

Update TAU　

Mobile Originating Signalling Delay Tolerant Access

Emergency

Service Request

User plane radio resources request Mobile Originating Data/Delay Tolerant Access/Emergency

Uplink signaling resources request Mobile Originating Data/Delay Tolerant Access/Emergency Paging response for PS core network domain Mobile Terminating Access

PDN connectivity request with cause

‘emergency’ Emergency

Extended Service Request

Mobile originating CS fallback Mobile Originating Data/Delay Tolerant Access Mobile terminating CS fallback Mobile Terminating Access

Mobile originating CS fallback emergency call Emergency

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Initial UE Message



After RRC connect establishment , eNodeB delivers the first NAS message , which is carried by “RRC C

onnection Setup Complete” in Uu interface and “Initial UE Message” in S1 interface, to MME.



“Initial UE Message” includs the following NAS procedure:

 EMM: Attach request

 ESM: PDN connectivity request

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RRC Connection Reconfiguration Process

 Upon receiving an RRC Connection Reconfiguration message from the eNodeB over the radio i

nterface, a UE configures SRB2 and the default DRB and sends an RRC Reconfiguration Compl ete message to the eNodeB.

 Page27

 This process is also used for radio bearer management during E-RAB setup, no

specific message except for RRC

Connection Reconfiguration messages is

used for signaling exchange between eNodeBs and UEs.

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RRC Reconfiguration Case– SRB2&DRB Setup



Key IEs

 radioResourceConfiguration (for SRB2 and pos

sible DRBs) （ default bearer setup ）

 nas-DedicatedInformation （ default bearer s

etup ）



RRC Reconfiguration process can also be use

d for the following configuration ：

 measurementConfiguration （ measurement

control ）

 mobilityControlInformation （ handover com

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RRC Reconfiguration Case– Measurement Control Mess

age

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Release Process of Signaling Connection Overview

 This process involves the following releases:

 Release of S1 connection

 Release of RRC connection, including all radio bearers and signaling connections between UEs and eNodeBs

 The signaling connection release process starts in either of the following scenarios:

 The MME sends a UE Context Release Command message to the eNodeB.

 The eNodeB sends a UE Context Release Request message to the MME upon detecting the causes such as timer expi

ration in the eNodeB, a handover, or other radio events. In this situation, release process of signaling connection is t riggered when the MME responds with a UE Context Release Command message.

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Release Process of Signaling Connection

 Reasons for S1 Dedicated Signaling Release

1.eNodeB triggers ， for example, detect UE is in user inactivity for a long time 2.eNodeB O&M system triggers

3.MME O&M system triggers

2.1 Release Access Bearers Request

S-GW

eNodeB MME

1. S1-AP: S1 UE Context Release Request

3. S1-AP: S1 UE Context Release Command 4. RRC connection release

5. S1-AP: S1 UE Context Release Complete

UE

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Release of S1 Signaling Connection



Release of S1-AP and S1-U connections

 Before the S1 connection is released

 After the S1 connection is released

S-GW P-GW eNodeB MM E S-GW P-GW eNodeB MM E

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Release of Signaling Connection Cases



Key IEs

 MME UE S1AP ID  eNB UE S1AP ID  Cause

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

LTE Air Interface Physical Layer



LTE Cell acquisition and call setup



LTE Optimization



Basic cell parameters planning



LTE cell reselection Optimization



LTE Handover Optimization



LTE KPI



LTE Feature

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LTE Cell ID Planning

 The WCDMA cell ID is unique on each RNC, the GSM and CDMA cell ID also is similar to the WCDMA cell ID.

 Different from a WCDMA cell ID, LTE cell ID consists of 20 bits eNB ID and 8 bits cell ID, which ensures that the LTE cell ID i

s unique in the entire network. If the PLMN (MCC + MNC) is used, the LTE cell ID is unique worldwide.

 The eNB involves the local cell ID, eNodeB ID, and cell ID. It is advised to plan the three IDs starting from 0, which ensures

that they are consistent.

20bits eNodB ID 8bits Cell ID

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TA Planning



TA Concept

 Similar to the location area and routing area in 2G/3G networks, the tracking area (TA) is used for pag

ing. TA planning aims to reduce location update signaling caused by location changes in the LTE syste m.



TAI list

 A list of TAIs that identify the tracking areas that the UE can enter without performing a tracking area

updating procedure, i.e. in LTE system, if a UE changes the TAs in the TAI list, TA update won’t be trigg ered.

 The TAIs in a TAI list assigned by an MME to a UE belongs to the same MME area. Additionally, the TAI

s in a TAI list assigned by an MME to a UE supporting CS fallback pertain to the same location area. In this case, the defining of the relationship between the tracking area(s) and the location area(s) is oper ator specific.



TA Planning content

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TAU Procedure Classification

MME1

S-GW1

MME2

S-GW2

MME3

TA list 1 TA list 2 TA list 3 TA list 4

Periodic TAU

Intra MME TAU

Inter MME TAU with SGW change

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TA Planning Principles

A TA coverage should be medium. The limitations by the EPC must be considered.

When the suburban area and urban area are covered discontinuously, an independent TA is used for the sub urban area.

A TA should be planned for a continuous geographical area to prevent segmental networking of eNBs in eac h TA.

The paging area cannot be located in different MMEs.

The mountain or river in the planned area can be used as the border of a TA, where fewer location updates a re performed for a small quantity of users.

TA&TAL Planning Baseline Propose

scene eNB Num. Per

TA

TAL(eNB Num./TA Num.)

Urban 30~50 ₁₅₀ _{～ 300eNBs/3 ～ 10TAs}

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PCI Planning

In LTE system, the physical cell identifier (PCI) is used to differentiate radio signals of different cells. That is, the PCI is unique in the coverage of cells. Cell IDs are grouped in the cell search procedure. The ID of a cell group is determined through the SSCH, and then a specific cell ID is determined through the PSCH.

The function of PCIs in the LTE system is similar to that of scrambling codes in the WCDMA system. PCI pla nning also aims to ensure the reuse distance.

Differences between a scrambling code and a PCI: The scrambling code ranges from 0 to 511 whereas the PCI ranges from 0 to 503. In addition, the protocols do not have specific requirements for scrambling code planning. Therefore, only the reuse distance needs to be ensured in scrambling code planning. For PCI pla nning, however, 3GPP protocols require that the value of PCI/3 should be 0, 1, or 2 in each eNB.

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PRACH Planning - Logical Root Sequence Indexes



What is the logical root sequence index



logical root sequence index 0~820



The random access preambles are generated from Zadoff-Chu sequences with zero correlatio

n zone.



There are 64 available preamble sequences in each cell. The 64 preamble sequences are first

generated from a root Zadoff-Chu sequence using cyclic shift. If less than 64 preamble seque

nces are generated, the remaining are generated from the root Zadoff-Chu sequence corresp

onding to the logical index.



The previously mentioned root corresponds to

the logical root sequence index, which is sent

to the UE through the SIB2.

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Da Nang LTE Planning

GSM and UMTS Site Name DNL+Distr ict code+Nod eB ID(2 digitals) Local CellID start from 1 CellName based on eNodeB Name with extension "ABC for 1800, DEF for 2600", 1800 IBS start from "JKL", 2600 IBS use "MNO" CellID start from 1, depend on no of local cell. Huawei eNodeB ID from 501 to 550. Sector ID Start from 1, depend on no of sector. Huaw ei use PCI from 0~24 0, other vendo r use PCI from 251~ 490. TAC plann ing based on existi ng 3G LAC plann ing, 1TAC mapp ing to 1 3G LAC. BandWidth, 10M for 1800, 20M for 2600. 2T2R Huawei use Root Sequence Index from 0~400, other vendor use Root Sequence Index from 420~820.

NodeB Name eNodeB _Name Local CellID CellName CellID eNodeBID MCC MNC SectorID PCI TAC BandWidth DLEAR_FCN TxRx_Mode

ROOT SEQUENCE INDEX (PRACH) ReferenceS ignalPwr(0. 1dBm) DNHC02 DNL302 1 _DNL302A 1 501452 01 1 0 501CELL_BW_N50(10M) 15012T2R 0 ₁₈₂ DNHC02 DNL302 2 DNL302B 2 501452 01 2 1 501CELL_BW_N50(10M) 15012T2R 3 182 DNHC02 DNL302 3 DNL302C 3 501452 01 3 2 501CELL_BW_N50(10M) 15012T2R 6 182 DNHC08 DNL308 1 DNL308A 1 502452 01 1 30 501CELL_BW_N50(10M) 15012T2R 9 182 DNHC08 DNL308 2 DNL308B 2 502452 01 2 31 501CELL_BW_N50(10M) 15012T2R 12 182 DNHC08 DNL308 3 DNL308C 3 502452 01 3 32 501CELL_BW_N50(10M) 15012T2R 15 182

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

LTE Air Interface Physical Layer



LTE Cell acquisition and call setup



LTE Optimization



Basic cell parameters planning



LTE cell reselection Optimization



LTE Handover Optimization



LTE KPI



LTE Feature

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HUAWEI TECHNOLOGIES CO., LTD. Page 43 Low Prio.

NodeB/BTS High Prio.

eNodeB

SservingCell is worse than Thresh_serving.low &

SNonservingCell is better than Thresh_x.low

SNonservingCell is better than Thresh_x.high

Cell Reselection From Low > High

Cell Reselection

Cell Reselection Principle

Cell Reselection From High -> Low

GSM (Low) UMTS (Medium) LTE (High) SIB SIB SIB

Suggested RAT Priority:  LTE(High)

 UMTS(Medium)

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Camping - Cell Reselection between LTE and GSM/UMTS

 Threshold

 Thresh_x,high_{: threshold of reselecting to High Priority}

Cell

 Thresh_x,low_{: threshold of reselecting to Low Priority Cell}

 Measurement parameter

 S_ServingCell_{: Signal of serving cell}

 S_{NonServingCell}_{: Signal of target reselection cell}

 _{Threshold and Measurement}

 _L

T E

 GSM/UM TS

 Cell Reselection from GSM/UMTS to LTE network when UE enters the LTE coverage area

 _{Cell Reselection Strategy}

 _{LTE->GSM/UMTS (High to Low)}

 S_ServingCel_l<Thresh_serving,low & S_{NonServingCell}

>Threshx,low

 Length of camping on serving cell > 1 sec

 GSM/UMTS->LTE (Low to High)  S_{NonServingCell}> Thresh_x,high

 Cell Reselection from LTE to GSM/UMTS network

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LTE Parameter - Idle Mode Cell Reselection (Threshold)

Priority RAT 7 Reserved 6 L2600 5 L1800 4 Reserved 3 U2100 2 Reserved 1 G900\1800

_{Reselection from LTE to UMTS: (Coverage based)}

_{UE will start to measure UMTS signal when:}_{LTE signal < -110dBm}

_{UE will reselect to UMTS when:}_{LTE signal < -114dBm & UMTS signal >}

-103dBm, The signal conditions need to maintenance for 1 second.

_{Reselection from LTE to GSM: (Coverage based)}

_{UE will start to measure UMTS signal when:}_{LTE signal < -110dBm}

_{UE will reselect to UMTS when:}_{LTE signal < -114dBm & GSM signal >}

-101dBm, The signal conditions need to maintenance for 1 second.

_{Reselection from UMTS to LTE: (Priority based)}

_{Configure UMTS network priority as}₃_{, UE will always measure LTE signal}

when camping on UMTS.

_{UE will reselect to LTE when: U2L:}_{LTE signal > -108dBm} _{Reselection from GSM to LTE: (Priority based)}

_{Configure GSM network priority as}₁_{, UE will always measure LTE signal when}

camping on GSM.

_{UE will reselect to LTE when:}_{G2L: LTE signal > -108dBm} _{The signal}

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

LTE Air Interface Physical Layer



LTE Cell acquisition and call setup



LTE Optimization



Basic cell parameters planning



LTE cell reselection Optimization



LTE Handover Optimization



LTE KPI



LTE Feature

(47)



Three Scenarios for Handover Within System

Handover Outline

Handover Handover S1 S1 Handover X2 Uu Uu Uu Uu Uu Uu

Intra-eNodeB Handover Inter-eNodeB Handover with X2 Inter-eNodeB Handover with S1

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

Handover consists of three stages:

 HO Measurement: UE does the measurement based on the measurement configuration from eNo

deB, and report to eNodeB;

 HO Decision: It is eNodeB to decide if trigger handover based on the measurement result UE repo

rt;

 HO Execution: Based on the decision, eNodeB control UE handover to target cell;



The whole handover procedure follows

 network control and UE assistant.



Six steps needed

 Issuing Measurement Control-> Measurement Result Report->Handover Decision->Resource Prepar

ation->Handover Execution->Source cell Resource Release

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Key Impact Factors for Handover

_Device

fault

_{EPC fault}

• EPC replies handover preparation failure

• EPC fault causes abnormal handover flow

_{eNodeB fault}

• Relevant alarm exists for the modules

_{UE factor} • Specific UE problem  _Parameter s & channel _{Parameters issue}

• Incorrect handover event parameters

• Incorrect radius configuration

_{RF channel issue}

• UL interference

• RF channel problem Transport issue

• Incorrect configuration • Transmission fault  _Radio planning issues _{Coverage issue} • Poor coverage in handover area

• No major pilot in handover area  _Neighbor_issues • Missing neighbor • Mistake neighbor configuration/PCI conflict

• Black cell configuration

 Capacity issue

• Admission failure

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General Process



Determine the scale of problem

 From the performance statistic, we can determine the scale of the problem, is it global proble

m, or cell level problem or just some individual UE problem. Then we can select bottom N cell as optimization target

 Customer complain is an effective way to locate the individual UE problem



For large scale handover failure

 Check eNodeB alarm and basic configuration  Check EPC alarm and configuration

 Check RF channel problem



Once RF channel is abnormal, such as high VSWR, low RSSI Too Low or RSSI is un

balanced, then the access performance should be significantly affected.



After we exclude the hardware fault and transmission fault, we could analysis th

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Proceed for Signaling Analysis



Step 1: Located fault point

 From the tracing message, we can located the handover fault point, there’re 3 key fault points dur

ing handover procedure



No measurement report



No handover command



No handover complete message



Step 2: Analyze the root cause

 Channel quality issue  Configuration issue

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Generic Analysis Method



Channel quality problem

 Observe RSRP,RSRQ, SINR IBLER, DL/UL grant from driver test tools

 Observer performance monitoring from M2000 including scheduling statistic, CQI report, MCS, SI

NR eg.



Configuration problem

 Check the neighbor/ANR configuration  Check the X2 configuration

 Check EPC authentication & security configuration



Transmission problem

 Check relevant alarm

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Problem Analysis –No Measurement Control Message



Scenario : eNodeB doesn’t send measurement control message

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Problem Analysis – Black List Configuration



Scenario : UE receives measurement control message, but UE doesn’t send any

measurement report



Possible cause:

 The neighbor cell is in black list. In the SIB message eNodeB delivers all black cell list, then U

E doesn’t measure any of these cells



Solution: check if all the neighbor belongs to black list

 LST INTRAFREQBLKCELL  LST INTERFREQBLKCELL

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Case 1: Inter TA Handover Due to Missing IP Path

 Description: In one project, we find a lot of handover failure. From the statistic, we observe that most of t

hese failures happen between inter TA cell.

 Analysis

 From the tracing message, we see that the failure cause is handover preparation failure, the failure cause is GTUP

resource not available.

 In the handover request message, source eNodeB deliver the target GTPU ID (SGW IP address) to

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Solution



Later we confirm this issue, this TA border is also the border of two regions which use diffe

rent SGW. And in each region ,only one IP path is configured for current eNodeB to SGW. S

o the handover will be failure when cross the different SGW.



Solution

 Configure S1 IP path from the target eNodeB to source SGW, then the problem is solved



Suggestion: This is a very typical problem, on the border cell of inter SGW, we should reme

(60)

Case 2: Handover Failure Due to No Handover Comm

and

_

_{Description: UE sends measurement report to eNB several times , but no feed back fro}

m eNodeB

(61)

Case 2 – Analysis



From the previous message, we can see that before the measurement report, eNB sends one

“RRC reconfiguration” message, but the UE doesn’t feedback the complete message.



Then we check trace on UE side, and find that UE doesn’t receive the RRC reconfiguration mes

sage



Due to poor DL coverage, UE doesn’t receive the RRC reconfiguration

message, thus no complete feedback. As the previous RRC reconfiguration

procedure is not completed, eNodeB is still waiting for reconfiguration

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

LTE Air Interface Physical Layer



LTE Cell acquisition and call setup



LTE Optimization



LTE KPI



LTE Feature

(63)

KPI System Overview

Radio Network KPI :

Focus on the radio network performance

Service KPI :

Focus on the user experience

LTE KPIs

Accessability Retainability Mobility Integrity

RRC SETUP SR _ERAB Setup SR _Call Setup SR Call Drop Rate Call Setup Complete Rate Service UL/DL Throughput HHO SR ( Intra/Inte r Frequency ) _Inter-RAT HHO SR CSFB SR _Radio Network Unavailabi lity Rate Availability Cell UL/DL Traffic Volume Utilization UL/DL RB Utility Rate Traffic

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Collection Method and Reporting Period

 _{Collection methods (TS 32.403)}

 _{CC (Cumulative Counter), for example, Attempted RRC connection establishments;}

 _{GAUGE (dynamic variable), used when data being measured can vary up or down during}

the period of measurement, for example, Maximum E-RAB Setup time;

 _{DER (Discrete Event Registration), when data related to a particular event are captured}

every nth event is registered, where n can be 1 or larger, for example, Cell Unavailable Time;

 _{SI (Status Inspection), for example, Average Number of simultaneous E-RABs;}  _{Reporting period}

 _{The measurement results are collected in a pre-defined reporting period, and this}

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Danang LTE Trial KPI

Category KPI Items 17-Jul-16 18-Jul-16 19-Jul-16 20-Jul-16 21-Jul-16

Accessability KPIs

RRC Connection Establishment SR(%) 99.7365 99.842 99.8351 99.8442 99.8848 Initial E-RAB Establishment SR(%) 99.9551 99.9489 99.9578 99.9389 99.9567 Addition E-RAB Establishment SR(%) 99.4118 99.3827 100 99.5614 99.6403 Retainability KPI E-RAB Retainability for UE level(%) 0.3 0.2906 0.2498 0.2861 0.2554

Mobility KPIs

Inter eNB HO SR via X2(%) 99.3676 99.4014 99.5381 99.5501 99.6134 Inter eNB HO SR via S1(%) 100 99.7567 99.6805 99.6795 99.6324 Intra Frequency HO SR(%) 99.5056 99.5253 99.6358 99.6402 99.687 Inter Frequency HO SR(%) 99.6885 100 99.3186 99.6753 99.842 Inter-RAT HO Out SR (LTE to UMTS)(%) 95.6042 94.4228 92.3779 93.9486 95.1845 Integrity KPIs E-UTRAN IP Throughput DL(Kbps) 16328 13866.29 15223.5408 14770.3511 15250.2427

E-UTRAN IP Throughput UL(Kbps) 1785.255 1501.656 1813.6444 1362.1843 1644.9753 Traffic Data Traffic(GBits) 317.6122 302.4348 319.6397 295.3225 323.1579 CSFB CSFB Preparation Success rate (%) 99.9188 99.9366 99.9671 99.9838 99.9534 Available Available(%) 98.4375 98.3832 98.4313 98.4375 98.4322

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RRC Connection Establishment Success Rate

KPI Name RRC Connection Establishment Success Rate (service)

KPI Index

Managed Object

Cell

Formula RRCS_SR(RRCConnectionSuccessservice = _service/RRCConnectionAttempt_service) * 100%

Related PM

RRC Setup Success Rate (Service) =((L.RRC.ConnReq.Succ.Emc + L.RRC.ConnReq.Succ.HighPri + L.RRC.ConnReq.Succ.Mt + L.RRC.ConnReq.Succ.MoData + L.RRC.ConnReq.Succ.DelayTol)/ (L.RRC.ConnReq.Att.Emc + L.RRC.ConnReq.Att.HighPri + L.RRC.ConnReq.Att.Mt + L.RRC.ConnReq.Att.MoData + L.RRC.ConnReq.Att.DelayTol)) *100% Mapping counter (1526728222+ 1526728223+ 1526728224+ 1526728226+ 1526728358)/( 1526728217+ 1526728218+ 1526728219+ 1526728221+ 1526728357 )*100% Unit % Description

According to 3GPP TS 36.331, the RRC connection setup procedure is triggered by different causes, which are identified in the

"establishmentCause" field in an RRC Connection Request message as emergency, highPriorityAccess, mt-Access,

mo-Signaling, mo-Data, or delayTolerantAccess-v1020. The UE sets the establishmentCause in accordance with the information it receives from upper layers. The mo-signaling cause is a signaling-related

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E-RAB Setup Success Rate

KPI Name E-RAB Setup Success Rate (All) KPI Index E-RAB Setup Success Rate (All)

Managed Object Cell Formula (ERABSetupSuccess/ERABSetupAttempt) *100% Related PM (L.E-RAB.SuccEst/L.E-RAB.AttEst) * 100% Mapping counter (1526727544/1526727545) * 100% Unit % Description

The E-RAB Setup Success Rate (All) KPI

indicates the E-RAB setup success rate for all services, including the VoIP service in a cell or radio network

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Call Drop Rate

KPI Name Service Drop Rate (All) KPI Index Service Drop Rate (All)

Managed Object Cell Formula (ERABAbnormalRelease/ERABRelease) * 100% Related PM (L.E-RAB.AbnormRel/(L.E-RAB.AbnormRel + L.E-RAB.NormRel)) * 100% Mapping counter (1526727546/ (1526727546+1526727547))*100% Unit %

Description The Service Drop Rate (All) KPI indicates the call drop rate of all the services in a cell or radio network, including the VoIP service.

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Intra Frequency Handover Success Rate

KPI Name Intra Frequency Handover Success Rate KPI Index IntraFreqHOOut_SR

Managed Object Cell

Formula (IntraFreqHOOutSuccess/IntraFreqHOOutAttempt) * 100%

Related PM

Intra-Frequency Handover Out Success Rate = [(L.HHO.IntraeNB.IntraFreq.ExecSuccOut + L.HHO.IntereNB.IntraFreq.ExecSuccOut)/(L.HHO.IntraeNB.IntraFreq.ExecAttOut +

L.HHO.IntereNB.IntraFreq.ExecAttOut)] * 100%

Mapping counter (1526726997 + 1526727003 )/( 1526726996 + 1526727002)*100

Unit %

Description

The Intra-Frequency Handover Out Success Rate KPI indicates the success rate of intra-frequency

handovers (HOs) from the local cell to neighboring E-UTRAN cells. The intra-frequency HOs are classified into intra- and inter-eNodeB HOs.

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Inter-RAT Handover Out Success Rate (LTE to UMTS)

KPI Name Inter-RAT Handover Out Success Rate (LTE to UMTS)

KPI Index IRATHO_L2W_SR

Managed Object Cell Formula (IRATHO_L2W_Success/IRATHO_L2W_Attempt ) * 100% Related PM (L.IRATHO.E2W.ExecSuccOut/L.IRATHO.E2W.ExecAtt Out) * 100% Mapping counter (1526726991 / 1526726990 ) * 100% Unit % Descriptio n

The Inter-RAT Handover Out Success Rate (LTE to WCDMA) KPI indicates the success rate of

handovers from an LTE cell or radio network to WCDMA networks

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CSFB Preparation Success Rate

KPI Name CSFB Preparation Success Rate KPI Index CSFB_Preparation_SR

Managed Object Cell Formula CSFB_Preparation_SR = (CSFB_Preparation_Success/CSFB_Prepar ation_Attempt) * 100% Related PM (L.CSFB.PrepSucc/L.CSFB.PrepAtt) * 100% Mapping counter (1526728322/1526728321)*100% Unit % Descriptio

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Cell Downlink Average Throughput

KPI Name Cell Downlink Average Throughput KPI Index CellDLAveThp

Managed

Object Cell

Formula CellDLAveThp = CellDLTrafficVolume/CellDLTransferTime

Related KPI Cell Downlink Average Throughput = L.Thrp.bits.DL/L.Thrp.Time.Cell.DL.HighPrecision

Mapping

counter (1526728261/1526728997) Unit Kbps

Description The Cell Downlink Average Throughput KPI indicates a cell's average downlink throughput when data is

transferring at the downlink. The Cell Downlink Average Throughput KPI reflects the cell's capacity.

 _{L.Thrp.bits.DL : The traffic volume of transmitted}_{PDCP SDUs of services with a specific QCI}

ranging from 1 to 9 is accumulated as the value of the corresponding counter.

 _{L.Thrp.Time.Cell.DL.HighPrecision: The duration of uplink or downlink data transmission in a}

cell is sampled per millisecond. If there is uplink or downlink data transmission within a sampling period, the sampling result is 1 ms. At the end of a measurement period, the sum of these sampling results is used as the value of the L.Thrp.Time.Cell.DL.HighPrecision counter.

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Cell Uplink Average Throughput

KPI Name Cell Uplink Average Throughput KPI Index CellULAveThp

Managed

Object Cell

Formula CellULAveThp = CellULTrafficVolume/CellULTransferTime

Related KPI L.Thrp.bits.UL/L.Thrp.Time.Cell.UL.HighPrecision

Mapping counter

Unit

Description The Cell Uplink Average Throughput KPI indicates the average cell uplink throughput when data is transferring

at the uplink. The Cell Uplink Average Throughput KPI reflects the cell's capacity

 _{L.Thrp.bits.UL : The traffic volume of transmitted}_{PDCP SDUs of services with a specific QCI}

ranging from 1 to 9 is accumulated as the value of the corresponding counter.

 _{L.Thrp.Time.Cell.UL.HighPrecision: The duration of uplink or downlink data transmission in a}

cell is sampled per millisecond. If there is uplink or downlink data transmission within a sampling period, the sampling result is 1 ms. At the end of a measurement period, the sum of these sampling results is used as the value of the L.Thrp.Time.Cell.UL.HighPrecision counter.

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

LTE Air Interface Physical Layer



LTE Cell acquisition and call setup



LTE Optimization



LTE KPI



LTE Feature

Background

 The Automatic Neighbor Relation (ANR) feature manages neighbor cell lists (NCLs) on the eNodeB side. ANR au

tomatically detects and adds new neighboring cells to neighbor relation tables (NRTs). In addition, ANR autom atically identifies and removes redundant neighboring cells and neighbor relationships.

 The ANR feature automatically maintains the neighbor relationship, reducing manual intervention in the maint

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NCL

 The NCLs of an eNodeB contain information about the external cells of the eNodeB, which belong t

o other base stations. NCLs are categorized as intra- and inter-RAT NCLs. Each eNodeB has one intr a-RAT NCL and multiple inter-RAT NCLs, such as the GERAN NCL and the UTRAN NCL.

 An NCL records the information about an external cell, such as the E-UTRAN cell global identifier (E

CGI) or the UTRAN/GERAN CGI, public land mobile network (PLMN), physical cell identifier (PCI), tra cking area code (TAC), eNodeB ID, and E-UTRA absolute radio frequency channel number (EARFCN).

SN Target Cell PLMN eNodeB ID Cell ID DlEarfcn PhyCellId TAC

1 46001 eNodeB ID#1 Cell ID#1 F1 PhyCellId#1 TAC#1 2 46001 eNodeB ID#2 Cell ID#2 F2 PhyCellId#2 TAC#2 3 46001 eNodeB ID#3 Cell ID#3 F1 PhyCellId#3 TAC#3

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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential ₇₇

NRT

 The NRTs of a cell contain information about the neighbor relationships of the cell with its neighboring

cells.

 Each cell has one intra-RAT intra-frequency NRT, one intra-RAT frequency NRT, and multiple

inter-RAT NRTs.

SN LCI Target Cell

PLMN

eNodeB ID Cell ID No Remove No HO

1 LCI#1 46001 eNodeB ID#1 Cell ID#1 FORBID_RMV FORBID_HO 2 LCI#1 46001 eNodeB ID#2 Cell ID#2 PERMIT_RMV PERMIT_HO 3 LCI#1 46001 eNodeB ID#3 Cell ID#3 FORBID_RMV FORBID_HO

Basic Concepts (2)

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Description:

UE can detect new neighboring cells and report CGI measurement result by Event ANR.

During handover procedure, target cell adds source cell as NR by UE history information. (only for intra-RAT)

Event Triggered ANR

NRT of Cell1

Cell2: PCI=2 CGI=17 ……

Cell3: PCI=5 CGI=25

3Add Cell2 in NCL of eNodeB1 and NRT of Cell1 by Event ANR (UE measurement)

U2000

eNodeB1 Cell1 Source Cell PCI=3 CGI= 27

1Detect new Cell2 PCI and CGI by Event ANR

2Report CGI and PCI of Cell2 eNodeB2 Cell2_N-Cell PCI=4 CGI=17

eNodeB3 Cell3 N-Cell

PCI=5 CGI=25

CGI: Global cell ID PCI: Physical Cell ID

HO from Cell1 to Cell2

6Add Cell1 in NCL of eNodeB2 and NRT of Cell2 by Event ANR (UE history info.)

3Add Cell3 in NCL of eNodeB1 and NRT of Cell1 by Fast ANR

NRT of Cell2

Cell1: PCI=3 CGI=27

…… ₄

5 Cell2 obtains CGI of Cell1 by UE history info, and queries PCI info from U2000.

1 Detect new Cell3 PCI and CGI by Fast ANR

2 Report CGI and PCI of Cell3

Fast ANR

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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential ₇₉

Description

 The following three criterions can be applied in Intra-LTE ANR auto deletion

Wrongly configured neighboring cells deletion: Periodic trigger (The same as eRAN7.0)

Redundant neighboring cells deletion : Periodic trigger (Newly added in eRAN7.0) Auto deletion when NRT has reached the maximum : Event trigger (Enhanced in

eRAN7.0)

 The three criterions can take effect independently.

Description

The following three criterions can be applied in Intra-LTE ANR auto deletion

Wrongly configured neighboring cells deletion: Periodic trigger (The same as eRAN7.0)

Redundant neighboring cells deletion : Periodic trigger (Newly added in eRAN7.0)

Auto deletion when NRT has reached the maximum : Event trigger (Enhanced in eRAN7.0)

The three criterions can take effect independently.

NRT/NCL Deletion Policies

If handover success rate of Ncell is below threshold, the NCL/NRT will be deleted. Period: ANR.StatisticPeriod HO success rate threshold: ANR. DelCellThd

(Default value 0%)

Wrongly configured Ncells deletion

Auto deletion when NRT is maxed out. If the Ncell has never been

handover to for a period of time, the NRT will be deleted.

Period:

4*ANR.StatisticPeriodForNRTDel Redundant Ncells deletion

Ncells which have never been measured by UE will be deleted.

Period:

ANR.StatisticPeriodForNRTDel

Ncells which has not been measured for a period of time will be deleted. Period: ANR.StatisticPeriodForNRTDel

If no Ncells meet the condition

Y

Ncells to which HO hasn’t happened for a period of time will be deleted. Period: ANR.StatisticPeriodForNRTDel

If no Ncells meet the condition

Ncells to which the handover times are below threshold

and ranked with descent of HO times in the last position will be deleted. Handover threshold is configurable. ANR.NcellHoForNRTDelThd

ANR.StatisticNumForNRTDel > 0

N

If the NCL has no NRT and X2 in period, NCL will be deleted.

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The information in this document may contain predictive statements including, without limitation, statements regarding the future financial and operating results, future product portfolio, new technology, etc. There are a number of factors that could cause actual results and developments to differ materially from those expressed or implied in the predictive statements. Therefore, such information is provided for