FDD LTE Key Performance Indicators Description Guide

Internal Use Only▲

FDD LTE Key Performance Indicators Description Guide

CDMA & FDD LTE Product Support Department


Learning Objectives

After having learned this training course, you should be able to understand:

Basic knowledge of FDD LTE KPIs

Categories of FDD LTE KPIs

Formulas of FDD LTE KPIs


Contents

Basic Knowledge of FDD LTE KPIs

FDD LTE eNodeB KPIs

FDD LTE Network KPIs

Other FDD LTE KPIs


References

Counters, Definitions, and Numbering Conventions

For more information, refer to the NetNumen M31(LTE) NE Management System eNodeB Performance Counter Reference at the following URL:

http://tsm.zte.com.cn/tsm/FileCenter/File.aspx?Mode=read&FileID=30341574

Formulas

For more information, refer to the NetNumen M31(LTE) NE Management System eNodeB Key Performance Indicator Reference at the following URL:





Counter Example

Measurement Object

Measurement Number

Measurement Type

Counter NameCounter Sequence Number

Cell Type 37320Statistics of RRC Connection Establishment

Number of Successful mt-Access RRC Connection Establishment

C373200000

Example

Counter


Counter Structure

Measurement Object

ID: 780-799

• Cell Type• eNodeB Type• eNodeB IP Link

Type• Cell Pair Type

Measurement Type

ID: 373320-373399

• Statistics of RRC connection establishment

• Statistics of E-RAB• Statistics of time• Type of a cell pair• Other

Counter

ID: C + Measurement Type Number + XXX

• Number of successful mt-Access RRC connection establishment

• Number of unsuccessful mt-Access RRC connection establishment (timer timeout)

• Other

KPI/PI

KPI ID: 310500-310799

• RRC connection establishment success rate

• Other

PI ID: 310500-310799

• Paging congestion rate

• Other


Reporting Procedure

This reporting procedure is described as follows:

Step 1 The RNLC subsystem reports data to the OAM using the event-triggered reporting mechanism.

Step 2 The CMAC, RNLU, BRS, or OSS subsystem reports data to the OAM every 10 seconds.

Step 3 The OAM synchronizes data with the OMC for each measurement object every 15 minutes.

OAM OMCBoard

10S reporting

15-minute data synchronization

RNLC

Event-triggered reporting


KPI Overview

Description Mobile subscriber (Serviceability + Reliability): An FDD LTE can provide a

mobile subscriber with high-quality, reliable, and long-term services. Mobile operator (Serviceability + Reliability + Traffic): An FDD LTE can provide

as many mobile subscribers as possible with high-quality, reliable, and long-term services.

Dependency System performance: UE + eNodeB + Transport + EPC Applicable environments: Bandwidth configuration, radio access, mobility

speed, service type, and so on

Categories FDD LTE eNodeB KPIs FDD LTE Network KPIs


Contents


FDD LTE eNodeB KPIs


Other FDD LTE KPIs


FDD LTE eNodeB KPIs

Latency

C-Plane Latency

U-Plane Latency

Throughput (Mono-UE)

Peak UE Data Rate

Average UE Data Rate

Cell Edge UE Data Rate

Cell Capacity (Multi-UE)

Peak Cell Throughput

Average Cell Throughput

Cell-Edge UE Throughput


U-Plane Latency

Round Trip Time

Dependency

Radio frequency: Under cell, mid-cell, and cell edge

Neighbor cell loading: Unloaded and loaded

Scheduling algorithm: Pre-scheduled and non-scheduled

Ping size: 32 B, 1000 B, and 1500 B

Application ServerCombined EPC

eNodeB

UE

ping

Measured Round Trip Time

Combined EPC

UE

ping

Measured Round Trip Time


C-Plane Latency

State Transition Time

Signaling Procedure

Camped - state (idle)

Active

Dormant

Less than 100msec

Less than 50msec

UE eNB MME

S1AP : INITIAL CONTEXT SETUP REQUEST

RRC : Paging

RRC : RRCConnectionRequest

RRC : RRCConnectionSetup

RRC : RRCConnectionSetupComplete+ NAS : SERVICE REQUEST

S1 AP: INITIAL UE MESSAGE+ NAS : SERVICE REQUEST

Security Mode Command

Security Mode Complete

RRC : RRCConnectionReconfiguration

RRC : RRCConnectionReconfigurationComplete

S1AP : PAGING

S1AP : INITIAL CONTEXT SETUP RESPONSE

Start of state transition time

Stop of state transition time

P RACH : PREAMBLE

PDCCH : TA + SCHEDULING GRANT



Peak UE Data Rate

Assumption

Loading: Single cell, unloaded

UE speed: Stationary mode

Location: Under cell (good RF conditions)

MIMO configuration: DL 2*2 MIMO, UL 1*2 SIMO

Dependency

Operating bandwidth

UE category

UE UL/DL RB limitation

Downlink or Uplink Data Stream

BSTerminal

Transmission

Application Server at NGMN network edge

E.g. Gateways,Routers,Firewalls

Downlink or Uplink Data Stream

BSTerminal

Transmission

Application Server at NGMN network edge





Average UE Data Rate

Assumption


Loading: 1 UE in the serving cell, neighbor cell loaded


Location: Uniformly-distributed locations over the signal quality range

Dependency

Operating bandwidth

UE category


UE distribution in each signal range



Cell-Edge UE Data Rate

Assumption


Loading: 1 UE in the serving cell, neighbor cell loaded


Location: Cell edge

Dependency

Operating bandwidth

UE category


UE SINR at the cell edge


Throughput (Multi-UE)

Peak Cell Throughput

Assumption


Loading: Multiple cells, loaded (70%)

UE Speed: Stationary mode

Location: Good RF conditions

Dependency

UE category: TBS limitation, 64QAM in UL


Environment: Dense urban, urban, suburban, and rural

Scheduling algorithm



Average Cell Throughput

Assumption


Loading: Multiple cells, loaded

UE speed: Stationary Mode

Location: Uniformly-distributed over the signal quality range

Dependency

UE category (TBS limitation, 64QAM in UL)


UE distribution in each signal range, scheduling algorithm

Typical UE Distribution Model

1113

2125

3238

123High224Middle123Low4610No. of UE



Cell-Edge UE Throughput

Assumption


Loading: Multiple cells, loaded (70%)


Location: Cell edge

Dependency

UE category (TBS limitation, 64QAM in UL)


Environment: Dense urban, urban, suburban, and rural

Scheduling algorithm

UE SINR at the cell edge


Contents


FDD LTE eNodeB KPIs


Other FDD LTE KPIs



Accessibility RRC Establishment Success Rate E-RAB Setup Success Rate

Retainability E-RAB Drop Rate

Mobility Handover Success Rate

Availability Cell Availability

Integrity Packet Loss Rate DL PDCP SDU Latency


Accessibility

KPI

KPI

Theoretical limit: 100%Ideal value in a commercial network: > 98%

S1-SIG Establish Success Rate

Initial E-RAB Setup Success Rate

Accessibility (Category)

Added E-RAB Setup

Success Rate

UE Context Setup Success Rate

RRC Connection Setup

Success Rate

RRC Connection Setup

Success Rate

Attach Success Rate

E-RAB Block Rate (per QCI)

S1-SIG Establish Success Rate

Paging Success Rate

RRC Re-Establishment

Success Rate

Contention-Based PRACH

Performance

Contention-Free PRACH

Performance

Detach Success Rate

E-RAB Setup Success Rate

Added E-RAB Accessibility

Initial E-RAB Accessibility

Call Setup Success Rate, Call Barring Rate、

Air Interface


RRC Establishment Success Rate Description

This KPI shows the probability for a subscriber to be provided with an RRCconnection upon request.

Signaling Procedure

Formula

RRC Establishment Success Rate = Number of successful RRC connection establishment / (Number of successful RRC connection establishment + Number of failed RRC connection establishment) * 100%

RRCConnectionSetup

RRCConnectionRequest

UE EUTRAN

RRCConnectionSetupComplete

1

2

3


E-RAB Setup Success Rate Description

This KPI shows the probability for a subscriber to be provided with an E-RAB request including initial and added context setup procedures.

Signaling Procedure

Formula

E-RAB Setup Success Rate = (Number of successful initial E-RAB + Number of successful added E-RAB establishment) / (Number of successful initial E-RAB establishment + Number of failed initial E-RAB establishment + Number of successful added E-RAB establishment + Number of failed added E-RAB establishment) * 100%

INITIAL CONTEXT SETUP RESPONSE

INITIAL CONTEXT SETUP REQUEST

eNB MME

E-RAB SETUP RESPONSE

E-RAB SETUP REQUEST

eNB MME

1

2

3

4


Retainability

KPI

Theoretical limit: 0%Ideal value in a commercial network: < 2%

Retainability (Category)

E-RAB DropRate

(Per QCI)

Active E-RABDrop Rate

RRC Drop RateUE E-RAB Retainability

UE E-RAB Retainability

Per QCI

E-RAB Duration Time per QCI Drop

E-RAB UL DataVolume

Per QCI Drop

E-RAB DL DataVolume

Per QCI Drop

How Often

QoS Before Drop

Percentage


E-RAB Drop Rate Description

This KPI shows the probability for an a subscriber to loss the E-RAB, such as an event being released by the eNodeB due to overload control.

Signaling Procedure

Formula

E-RAB Drop Rate = Number of Abnormally Released E-RAB / Number of SuccessfullyEstablished E-RAB * 100%

E-RAB RELEASE INDICATION

eNB MME

1

E-RAB Released by the eNodeB))


Mobility

Successful Handover Categories

All Incoming HO

Per Cell

All Incoming HO

Per Cell Pair

All Outgoing HO

Per Cell Pair

All Outgoing HO

Per Cell

Troubleshooting

Intra-Freq

Intra-eNodeB

Intra-Freq

Inter-eNodeB

Inter-Freq

Intra-eNodeB

Inter-Freq

Inter-eNodeB

Contention Based

HO

Contention Free

HO

Intra-RAT HO Success Rate

X2 Based HO S1 Based HO

LTE to UMTS UMTS to LTE GSM to LTELTE to GSM

Inter-RAT HO Success Rate


Mobility

Handover

Handover Preparation Success Rate

Theoretical limit: 100%

Ideal value in a commercial network： 99%

(Step 4 – Step 6)

Handover Execution Success Rate


Ideal value in a commercial network: 98%

HO In: Step 6 – Step 11

HO Out: Step 7 – Step 17

Mobility Success Rate


Ideal value in a commercial network: 97%RExecutionSHOReparationSHOMobilitySR .Pr.

packet data packet data

UL allocation

2. Measurement Reports

3. HO decision

4. Handover Request

5. Admission Control

6. Handover Request Ack

7.RRC Conn. Reconf. incl.

mobilityControlinformation

DL allocation

Data Forwarding

11. RRC Conn. Reconf. Complete

17. UE Context Release

12. Path Switch Request

UE Source eNB Target eNB Serving Gateway

Detach from old cell and

synchronize to new cell

Deliver buffered and in transit packets to target eNB

Buffer packets from Source eNB

9. Synchronisation

10. UL allocation + TA for UE

packet data

packet data

1. Measurement Control

16.Path Switch Request Ack

18. Release Resources

Han

dove

r Com

ple

tion

Ha

ndov

er E

xecu

tion

Han

dove

r P

repa

ratio

n

MME

0. Area Restriction Provided

13. User Plane update request

15.User Plane update response

14. Switch DL path

SN Status Transfer8.

End Marker

End Marker

packet data

Interruption Tim

e

Latency

Legend

L3 signalling

L1/L2 signalling

User Data


Handover Preparation and Execution

Handover Start Point Stop Point

Outgoing handover preparation

The source eNodeB decides to perform a handover.

The source eNodeB sends the RRC Connection Reconfiguration message to the UE.

Outgoing handover execution

The source eNodeB sends the RRC Connection Reconfiguration message to the UE.

The source eNodeB receives the UE Context Release message from the destination eNodeB.

Incoming handover preparation

The destination eNodeB receives the Handover Request message from the source eNodeB.

The destination eNodeB returns the Handover Response message to the source eNodeB.

Incoming handover execution

The destination eNodeB receives the RRC Connection Reconfiguration Complete message from the UE.

The destination eNodeB sends the UE Context Release message to the source eNodeB.


Cell Handover and Cell Pair Handover

The outgoing handover preparation success rate for each handover pair measures the

handover preparation from the serving cell to a certain neighbor cell. Here are two typical

examples:

In the event of the handover from cell A to cell B, the Intra-eNodeB Intra-freq Outgoing

Handover Preparation Success Rate per Cell pair is measured in cell A.

In the event of the handover from cell B to cell A, the Intra-eNodeB Intra-freq Outgoing

Handover Preparation Success Rate per Cell pair is measured in cell B.

The outgoing handover success rate contains all outgoing handover preparation successes

from the serving cell to all neighbor cells.

The measurement of these two KPIs can facilitate us in sifting two cells that suffer most

handover preparation failures, performing neighbor cell optimization, and even deleting

unusable neighbor cells.


Intra-eNodeB Handover Success Rate

Description

The intra-eNodeB handover success rate measures the service continuity when a subscriber is on the move. This KPI is perceptible to the subscribers, depending on system handover processing capabilities and network planning.

Formulas

Intra-frequency handover success rate = Number of intra-frequency handover successes / Number of intra-frequency handover requests * 100%

Inter-frequency handover success rate = Number of inter-frequency handover successes / Number of inter-frequency handover requests * 100%


Intra-eNodeB Handover Success Rate

Note:

If the eNodeB receives the RRC Connection Reconfiguration Complete message in step 4, it indicates that the handover is successful.

If the eNodeB receives the RRC Connection Reestablishment Request message in step 6, it indicates that the handover is unsuccessful.

RRC Connection Reconfiguration

Measurement Report

UE EUTRAN

RRC Connection Reestablishment Request

1

2

6

RRC Connection Reconfiguration Complete 4


3


Description

The inter-eNodeB X2-interface handover success rate measures the handover successes when the UE moves between the eNodeBs over the X2 interface. This KPI is perceptible to the subscribers being on the move, depending on system handover processing capabilities and network planning.

Formulas

Outgoing intra-frequency X2-interface handover success rate = Number of outgoing intra-frequency X2-interface handover successes / Number of outgoing intra-frequency X2-interface handover attempts (serving cell) * 100%

Incoming intra-frequency X2-interface handover success rate = Number of incoming intra-frequency X2-interface handover successes / Number of incoming intra-frequency X2-interface handover attempts (serving cell) * 100%

Outgoing inter-frequency X2-interface handover success rate = Number of outgoing inter-frequency X2-interface handover successes / Number of outgoing inter-frequency X2-interface handover attempts (serving cell) * 100%

Incoming inter-frequency X2-interface handover success rate = Number of incoming inter-frequency X2-interface handover successes / Number of incoming inter-frequency X2-interface handover attempts (serving cell) * 100%

Inter-eNodeB X2-Interface Handover Success Rate


Inter-eNodeB X2-Interface Handover Success Rate

MME

Measurement Report

UE SOURCE EUTRAN

TARGET EUTRAN

Handover Request

Handover Request Acknowledge


RRC Connection Reconfiguration Complete

Path Switch Request

Path Switch Request Ack

Path Switch Request Failure

UE Context Release

8

9

11

12

13

14

1516

Handover Preparation Failure

1

3

2

4

6


5


Path Switch Request Ack

7

UE Context Release

17

18


Description

When the eNodeB decides to perform a handover according to the UE measurement report and meanwhile the destination cell is not connected to the eNodeB through the X2 interface, the inter-eNodeB S1-interface handover success rate measures the S1-interface handover performed through the EPC. This KPI is perceptible to the subscribers being on the move, depending on system handover processing capabilities and network planning.

Formulas

Outgoing intra-frequency S1-interface handover success rate = Number of outgoing intra-frequency S1-interface handover successes / Number of outgoing intra-frequency S1-interface handover attempts (serving cell) * 100%

Incoming intra-frequency S1-interface handover success rate = Number of incoming intra-frequency S1-interface handover successes / Number of incoming intra-frequency S1-interface handover attempts (serving cell) * 100%

Outgoing inter-frequency S1-interface handover success rate = Number of outgoing inter-frequency S1-interface handover successes / Number of outgoing inter-frequency S1-interface handover attempts (serving cell) * 100%

Incoming inter-frequency S1-interface handover success rate = Number of incoming inter-frequency S1-interface handover successes / Number of incoming inter-frequency S1-interface handover attempts (serving cell) * 100%

Inter-eNodeB S1-Interface Handover Success Rate


Inter-eNodeB S1-Interface Handover Success Rate

Measurement Report

UE SOURCE EUTRAN

TARGET EUTRAN

Handover Required


MME

Handover Request

Handover Command



Handover Notify

UE Context Release Command

8

9

10

11

12

13

2

4

1

3

Handover Failure

Handover Preparation Failure7

Handover Command5

6

UE Context Release Command14



Inter-System Handover Success Rate

The inter-system handover success rate consists of both incoming and outgoing handover between the LTE network and the CDMA network, between the LTE network and the UMTS network, between the LTE network and the GSM network. This example shows a handover from the CDMA network to the LTE network.

Measurement Report

UE CDMA TARGET EUTRAN

Handover Required


MME

Handover Request

Handover Command



Handover Notify

4

5

6

1

2

Handover Failure

Handover Preparation Failure

3



Availability

Availability

Cell availability


Ideal value in a commercial network: > 99.995%

100_

]ime.[causeavailableTRRU.CellUn-t_periodmeasuremencause

periodtmeasuremenbilityCellAvaila

Dependency

Software + Hardware

Unavailable Time = Unplanned downtime only (excluding planned downtime)

Physical meaning

365 * 24 * 60 * (1-99.995%) = 26.28 min cell out-of-service time

Important and Demanding


Cell Availability Description

The cell availability measures the ratio of in-service time to measurement granularity time. The in-service time indicates the time interval between cell establishment and cell deletion. By counting the cell in-service time, this KPI forms a foundation for analyzing system failures and measuring system stability.

Signaling Procedure

FormulasCell Availability = In-Service Time / Measurement Granularity TimeCell Availability = C373230700 / Measurement Granularity Time * 100%

CRM CCM CCMI

EV_CRM_CCM_CELL_CONFIG_REQ

EV_CRM_CCM_CELL_CONFIG_REQ

EV_CRM_CCM_CELL_DEL_REQ

EV_CRM_CCM_CELL_DEL_REQ

After the RNLU/CMAC/RRU is successfully configured, the cell service start time is recorded.

After the RNLU/CMAC/RRU is successfully deleted, the cell service stop time is recorded.

When being power on, the CCM starts the timer every 15 minutes to report the service t ime of each cell to the PM, and then clears statistical data.

The DRM may initializes the cell deletion due to one of the following reasons:1. Normal cell deletion2. Cell establishment timeout3. Cell establishment failure4. Manual blocking/unblocking5. Auditing failure6. S1 link disconnection


Integrity

UL/DL Packet Loss Rate

DL PDCP SDU Latency

QCI Resource

Type

Priority Packet Latency Budget

(NOTE 1)

Packet Error LossRate

(NOTE 2)

Example Services

1(NOTE 3)

2 100 ms 10-2 Conversational Voice

2(NOTE 3) GBR

4 150 ms 10-3 Conversational Video (Live Streaming)

3(NOTE 3)

3 50 ms 10-3 Real Time Gaming

4(NOTE 3)

5 300 ms 10-6 Non-Conversational Video (Buffered Streaming)

5(NOTE 3)

1 100 ms 10-6 IMS Signalling

6(NOTE 4) 6 300 ms 10-6

Video (Buffered Streaming)TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)

7(NOTE 3)

Non-GBR 7 100 ms 10-3

Voice,Video (Live Streaming)Interactive Gaming

8(NOTE 5) 8

300 ms 10-6Video (Buffered Streaming)TCP-based (e.g., www, e-mail, chat, ftp, p2p file

9(NOTE 6)

9 File sharing, progressive video, etc.


Downlink PDCP SDU Latency Description

This KPI indicates average downlink PDCP SDU latency based on the QCI type, from the time when a PDCP SDU reaches the eNodeB, to the time when the UE receives this PDCP SDU, that is to say, all fragments of this PDCP SDU receives a successful HARQ response.

Signaling Procedure

Formula Average Downlink PDCP SDU Latency = Total Latency of All PDCP SDUs / Number of All

PDCP SDUs


Downlink IP Packet Latency Description

This KPI indicates average downlink IP packet latency, from the time when the eNodeB receives the IP packet through the S1 or X2 interface, to the time when the first fragment of this IP packet is transmitted by the eNodeB through the air interface. It measures the time interval at which the service is processed by the eNodeB, which forms a strong foundation for network optimization.

Signaling Procedure

FormulaAverage Downlink IP Packet Latency (QCI 1 – 9) = Total Downlink IP Packet Latency (QCI 1 – 9 ) / Number of All PDCP SDUs (Downlink QCI 1 – 9)

UE EUTRAN

SGW

IP Packet 1 1

1st Fragment of IP Packet 1 2


Uplink/Downlink Packet Loss Rate

DescriptionThis KPI measures the ratio of discarded PDCP SDUs to received PDCP SDUs

due to the timeout of the TimeDisCard timer, when no, partial, or all fragments are transmitted

through the eNodeB or air interface. It should be noted that PDCP SDUs vary

from QCI to QCI (1 – 9), from uplink to downlink.

CountersNumber of All PDCP SDUs

Uplink: When the PDCP layer of the eNodeB receives the PDCP SDU

from the UE, this counter is incremented by 1.

Downlink: When the PDCP layer of the eNodeB sends the PDCP SDU

to the RLC layer, this counter is incremented by 1.

Number of Discarded PDCP SDUs

Uplink: When the PDCP layer of the eNodeB receives the PDCP SDU

from the UE, the SN is not consecutive.

Downlink: When the PDCP layer of the eNodeB sends the PDCP SDU

to the RLC layer, the SN is not consecutive.

Formula Air Interface or eNodeB Packet Loss Rate = Number of Discarded Packets

over the Air Interface or eNodeB / Number of All Packets over the Air Interface or eNodeB


Contents


FDD LTE eNodeB KPIs


Other FDD LTE KPIs


Traffic Type - Number of RRC Connections Description

This KPI counts the number of RRC connections, which is used to measure the UE access to the system for call hold. It involves the following two counters: Average number of RRC connections Maximum number of RRC connections.

Signaling Procedure

When the eNodeB receives the RRC Establishment Complete message, the number of RRC connections is incremented by 1.

When the eNodeB triggers the RRC establishment successfully due to the handover, the number of RRC connections is incremented by 1.

When the eNodeB releases the RRC connection, the number of RRC connections is decremented by 1.

When the eNodeB reestablishes the RRC connection in another cell, the number of RRC connections is decremented by 1.

When the eNodeB reestablishes the RRC connection back to the serving cell, the number of RRC connections is incremented by 1.

Formulas

Maximum Number of RRC Connections (Sampling Counter) Average Number of RRC Connections (Sampling Counter)


Traffic Type – Average Number of QCI-Based UEs Description

This KPI measures the average number of E-RAB connections, which evaluates network traffic. It should be noted that this KPI varies from QCI to QCI.

Signaling Procedure (Sampling Counter)

Initial E-RAB establishment success

Added E-RAB establishment success

Incoming E-RAB handover success

Incoming E-RAB modification success (changing the new QCI to the old QCI)

Outgoing E-RAB handover success

Outgoing E-RAB modification success (changing the old QCI to the new QCI)

E-RAB release

Formula

This KPI is counted by averaging the measured values of all sampling points within a specific measurement cycle.


Traffic Type – Number of Activated QCI-Based UEs

Description

This KPI counts the number of UEs in the cache during a specified time period. It can be measured based on a specific QCI, uplink or downlink, average number or maximum number.

This KPI indicates the number of in-service UEs in the system, which forms a foundation for evaluating system capacity and capabilities.

Signaling Procedure

N/A

Formula

This KPI is counted when any data is present in the E-RAB cache of QCI i every sampling cycle (100 ms), as defined in the 3GPP TS.


Resource AllocationCell & System Resources

(Category)

UL -C PRB Usage UL -U PRB Usage

UL PRB Usage per QCI

DL -C PRB UsageDL -U PRB Usage

DL PRB Usage per QCI

Avg CPU Load Avg DSP Load

PRACH Usage PRACHMessage Load

PRACH Propagation Delay

Paging Congestion Rate

PDCCH UsageTotal UL PRB Usage

Total DL PRB Usage

Avg DLTransmission Power

Avg ULInterference

Per PRB

FDD LTE Key Performance Indicators Description Guide

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