FDD LTE Key Performance Indicator
s Description Guide
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 eNod
eB 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 eNod
eB Key Performance Indicator Reference at the following URL:
http://tsm.zte.com.cn/tsm/FileCenter/File.aspx?Mode=read&FileID=30341576
Counter Example
Counter
Example
Measurement
Object
Measurement
Number
Measurement
Type
Counter Name
Counter
Sequence
Number
Cell Type
37320
Statistics of RRC
Connection
Establishment
Number of Successful mtAccess RRC Connection
Establishment
C373200000
Counter Structure
Measurement
Object
Measurement
Type
ID: 780-799
•
•
•
•
Cell Type
eNodeB Type
eNodeB IP Link
Type
Cell Pair Type
Counter
ID: 373320-373399
•
•
•
•
•
Statistics of RRC
connection
establishment
Statistics of E-RAB
Statistics of time
Type of a cell pair
Other
ID: C + Measurement
Type Number +
XXX
•
•
•
Number of
successful mtAccess RRC
connection
establishment
Number of
unsuccessful mtAccess 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.
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 longterm 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




Basic Knowledge of FDD LTE KPIs
FDD LTE eNodeB KPIs
FDD LTE Network 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
Combined EPC Application Server
eNodeB
UE
ping
Measured 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
C-Plane Latency
 State Transition Time
 Signaling Procedure
Throughput (Mono-UE)
 Peak UE Data Rate
Transmission
Terminal
BS
DownlinkorUplinkDataStream
 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
E.g. Gateways,
Routers,
Firewalls
Application Server
at NGMN network edge
Throughput (Mono-UE)
 Average UE Data Rate
 Assumption

MIMO configuration: DL 2*2 MIMO, UL 1*2 SIMO

Loading: 1 UE in the serving cell, neighbor cell loaded

UE speed: Stationary mode

Location: Uniformly-distributed locations over the signal quality range
 Dependency

Operating bandwidth

UE category

UE UL/DL RB limitation

UE distribution in each signal range
Throughput (Mono-UE)
 Cell-Edge UE Data Rate
 Assumption

MIMO configuration: DL 2*2 MIMO, UL 1*2 SIMO

Loading: 1 UE in the serving cell, neighbor cell loaded

UE speed: Stationary mode

Location: Cell edge
 Dependency

Operating bandwidth

UE category

UE UL/DL RB limitation

UE SINR at the cell edge
Throughput (Multi-UE)
 Peak Cell Throughput
 Assumption

MIMO configuration: DL 2*2 MIMO, UL 1*2 SIMO

Loading: Multiple cells, loaded (70%)

UE Speed: Stationary mode

Location: Good RF conditions
 Dependency

UE category: TBS limitation, 64QAM in UL

UE UL/DL RB limitation

Environment: Dense urban, urban, suburban, and rural

Scheduling algorithm
Throughput (Multi-UE)
 Average Cell Throughput
Typical UE Distribution Model
 Assumption

MIMO configuration: DL 2*2 MIMO, UL 1*2 SIMO

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 UL/DL RB limitation

UE distribution in each signal range, scheduling algorithm
Throughput (Multi-UE)
 Cell-Edge UE Throughput
 Assumption

MIMO configuration: DL 2*2 MIMO, UL 1*2 SIMO

Loading: Multiple cells, loaded (70%)

UE speed: Stationary mode

Location: Cell edge
 Dependency

UE category (TBS limitation, 64QAM in UL)

UE UL/DL RB limitation

Environment: Dense urban, urban, suburban, and rural

Scheduling algorithm

UE SINR at the cell edge
Contents




Basic Knowledge of FDD LTE KPIs
FDD LTE eNodeB KPIs
FDD LTE Network KPIs
Other FDD LTE KPIs
FDD LTE Network 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
Theoretical limit: 100%
Ideal value in a commercial network: > 98%
Accessibility
(Category)
Initial E-RAB
Accessibility
KPI
RRC Connection
Setup
Success Rate
S1-SIG Establish
Success Rate
Initial E-RAB Setup
Success Rate
Added E-RAB
Accessibility
Attach Success Rate
Detach Success Rate
RRC
Re-Establishment
Success Rate
Paging Success Rate
Air Interface
RRC Connection
Setup
Success Rate
S1-SIG Establish
Success Rate
KPI
UE Context Setup
Success Rate
Added E-RAB
Setup
Success Rate
E-RAB Setup
Success Rate
E-RAB Block Rate
(per QCI)
Call Setup Success
、 Rate, Call Barring Rate
Contention-Based
PRACH
Performance
Contention-Free
PRACH
Performance
RRC Establishment Success Rate

Description
This KPI shows the probability for a subscriber to be provided with an RRC
connection upon request.

Signaling
Procedure
UE
EUTRAN
RRCConnectionRequest
2
RRCConnectionSetup
RRCConnectionSetupComplete

1
3
Formula
RRC Establishment Success Rate = Number of successful RRC connection
establishment / (Number of successful RRC connection establishment + Number of
failed RRC connection establishment) * 100%
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
eNB
INITIAL CONTEXT SETUP REQUEST
INITIAL CONTEXT SETUP RESPONSE

eNB
MME
1
E-RAB SETUP REQUEST
E-RAB SETUP RESPONSE
2
MME
3
4
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-R
AB establishment + Number of successful added E-RAB establishment + Number of failed added E-RAB
establishment) * 100%
Retainability
Theoretical limit: 0%
Ideal value in a commercial network: < 2%
Retainability
(Category)
KPI
UE E-RAB
Retainability
Per QCI
UE E-RAB
Retainability
RRC Drop Rate
E-RAB Drop
Rate
(Per QCI)
How Often
E-RAB Duration
Time per QCI Drop
Percentage
E-RAB UL Data
Volume
Per QCI Drop
QoS Before Drop
E-RAB DL Data
Volume
Per QCI Drop
Active E-RAB
Drop Rate
E-RAB Drop Rate

Description
This KPI shows the probability for an a subscriber to loss the E-RAB, such as an event b
eing released by the eNodeB due to overload control.

Signaling Procedure
E-RAB Released by the eNodeB))
eNB
1

MME
E-RAB RELEASE INDICATION
Formula
E-RAB Drop Rate = Number of Abnormally Released E-RAB / Number of Successfully
Established E-RAB * 100%
Mobility
 Successful Handover Categories
Intra-Freq
Intra-eNodeB
Intra-Freq
Inter-eNodeB
Inter-Freq
Inter-eNodeB
Inter-Freq
Intra-eNodeB
LTE to UMTS
UMTS to LTE
LTE to GSM
Inter- RAT HO Success Rate
X2 Based HO
Contention Based
HO
S1 Based HO
All Incoming HO
Per Cell
All Outgoing HO
Per Cell
All Incoming HO
Per Cell Pair
All Outgoing HO
Per Cell Pair
Contention Free
HO
Intra-RAT HO Success Rate
Troubleshooting
GSM to LTE
Mobility
 Handover
 Handover Preparation Success Rate
 Theoretical limit: 100%
 Ideal value in a commercial network 、 99%
 (Step 4 – Step 6)
 Handover Execution Success Rate
 Theoretical limit: 100%
 Ideal value in a commercial network: 98%
 HO In: Step 6 – Step 11
 HO Out: Step 7 – Step 17
 Mobility Success Rate

Theoretical limit: 100%

Ideal value in a commercial network: 97%
MobilitySR= HO. Pr eparationSR × HO.ExecutionSR
Handover Preparation and Execution
Handover
Start Point
Outgoing handover
preparation
The source eNodeB decides to perform a
handover.
Stop Point
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 hando
ver 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 fr
om the serving cell to all neighbor cells.

The measurement of these two KPIs can facilitate us in sifting two cells that suffer most hando
ver preparation failures, performing neighbor cell optimization, and even deleting unusable nei
ghbor cells.
Intra-eNodeB Handover Success Rate

Description
The intra-eNodeB handover success rate measures the service continuity when a subs
criber is on the move. This KPI is perceptible to the subscribers, depending on system hand
over processing capabilities and network planning.

Formulas

Intra-frequency handover success rate = Number of intra-frequency handover succes
ses / Number of intra-frequency handover requests * 100%

Inter-frequency handover success rate = Number of inter-frequency handover succes
ses / 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 i
ndicates that the handover is successful.
 If the eNodeB receives the RRC Connection Reestablishment Request message in step 6, it i
ndicates that the handover is unsuccessful.
Inter-eNodeB X2-Interface Handover Success Rate
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 o
n the move, depending on system handover processing capabilities and network planning.


Formulas

Outgoing intra-frequency X2-interface handover success rate = Number of outgoing intra-freque
ncy X2-interface handover successes / Number of outgoing intra-frequency X2-interface handov
er attempts (serving cell) * 100%

Incoming intra-frequency X2-interface handover success rate = Number of incoming intra-freque
ncy X2-interface handover successes / Number of incoming intra-frequency X2-interface handov
er attempts (serving cell) * 100%

Outgoing inter-frequency X2-interface handover success rate = Number of outgoing inter-freque
ncy X2-interface handover successes / Number of outgoing inter-frequency X2-interface handov
er attempts (serving cell) * 100%

Incoming inter-frequency X2-interface handover success rate = Number of incoming inter-freque
ncy X2-interface handover successes / Number of incoming inter-frequency X2-interface handov
er attempts (serving cell) * 100%
Inter-eNodeB X2-Interface Handover Success Rate
Inter-eNodeB S1-Interface Handover Success Rate

Description
When the eNodeB decides to perform a handover according to the UE measurement report and me
anwhile the destination cell is not connected to the eNodeB through the X2 interface, the inter-eNod
eB 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-freque
ncy S1-interface handover successes / Number of outgoing intra-frequency S1-interface hando
ver attempts (serving cell) * 100%

Incoming intra-frequency S1-interface handover success rate = Number of incoming intra-frequ
ency S1-interface handover successes / Number of incoming intra-frequency S1-interface hand
over attempts (serving cell) * 100%

Outgoing inter-frequency S1-interface handover success rate = Number of outgoing inter-frequ
ency S1-interface handover successes / Number of outgoing inter-frequency S1-interface hand
over attempts (serving cell) * 100%

Incoming inter-frequency S1-interface handover success rate = Number of incoming inter-frequ
ency S1-interface handover successes / Number of incoming inter-frequency S1-interface hand
over attempts (serving cell) * 100%
Inter-eNodeB S1-Interface Handover Success Rate
Inter-System Handover Success Rate
The inter-system handover success rate consists of both incoming and outgoing handover between the LTE network and t
he CDMA network, between the LTE network and the UMTS network, between the LTE network and the GSM network. Thi
s example shows a handover from the CDMA network to the LTE network.
Availability
 Availability
Important and
Demanding
 Cell availability
 Theoretical limit: 100%
 Ideal value in a commercial network: > 99.995%
CellAvailability =
measurement_period- ∑ RRU.CellUnavailableTime.[cause]
cause
measurement _ period
 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
×100
Cell Availability

Description
The cell availability measures the ratio of in-service time to measurement granularity time. The inservice 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

Formulas
Cell Availability = In-Service Time / Measurement Granularity Time
Cell Availability = C373230700 / Measurement Granularity Time * 100%
Integrity
 UL/DL Packet Loss Rate
QCI
Priority
Packet
Latency
Budget
(NOTE 1)
Packet
Error
Loss
Rate
(NOTE
2)
2
100 ms
10-2
Conversational Voice
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
300 ms
10-6
Video (Buffered Streaming)
TCP-based (e.g., www, e-mail, chat, ftp, p2p file
sharing, progressive video, etc.)
7
100 ms
10-3
Voice,
Video (Live Streaming)
Interactive Gaming
300 ms
10-6
 DL PDCP SDU Latency
Resour
ce
Type
1
(NOTE 3)
2
(NOTE 3)
GBR
6
(NOTE 4)
7
(NOTE 3)
8
(NOTE 5)
9
(NOTE 6)
NonGBR
8
9
Example Services
Video (Buffered Streaming)
TCP-based (e.g., www, e-mail, chat, ftp, p2p file
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, th
at 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
Formula
Average Downlink IP Packet Latency (QCI 1 – 9) = Total Downlink IP Packet Latency (QCI 1 – 9 ) / N
umber of All PDCP SDUs (Downlink QCI 1 – 9)

Uplink/Downlink Packet Loss Rate

Description
This 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.

Counters
Number 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




Basic Knowledge of FDD LTE KPIs
FDD LTE eNodeB KPIs
FDD LTE Network 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 in
cremented by 1.

When the eNodeB triggers the RRC establishment successfully due to the handover, the number of RRC con
nections 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 decre
mented by 1.

When the eNodeB reestablishes the RRC connection back to the serving cell, the number of RRC connection
s 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 s
hould 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 meas
urement 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 m
easured 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 fo
r 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 Allocation
Cell & System
(Category)
Resources
UL -C PRB Usage
DL -C PRB Usage
Total UL
PRB Usage
PDCCH Usage
UL -U PRB Usage
PRACH Usage
UL PRB Usage
per QCI
Paging
Congestion Rate
Total D L
PRB Usage
Avg CPU Load
DL -U PRB Usage
Avg DL
Transmission Power
DL PRB Usage
per QCI
Avg UL
Interference
Per PRB
PRACH
Propagation Delay
Avg DSP Load
PRACH
Message Load