ETSI TS 128 554 V16.19.0 (2026-02)

5G; Management and orchestration; 5G end to end Key Performance Indicators (KPI) (3GPP TS 28.554 version 16.19.0 Release 16)

RTS/TSGS-0528554vgj0

General Information

• Status: Not Published
• Technical Committee: 3GPP SA 5 - Telecom Management
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Completion Date: 17-Feb-2026

Standards Content (Sample)

TECHNICAL SPECIFICATION
5G;
Management and orchestration;
5G end to end Key Performance Indicators (KPI)
(3GPP TS 28.554 version 16.19.0 Release 16)

3GPP TS 28.554 version 16.19.0 Release 16 1 ETSI TS 128 554 V16.19.0 (2026-02)

Reference
RTS/TSGS-0528554vgj0
Keywords
5G
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - APE 7112B
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° w061004871

Important notice
The present document can be downloaded from the
ETSI Search & Browse Standards application.
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format on ETSI deliver repository.
Users should be aware that the present document may be revised or have its status changed,
this information is available in the Milestones listing.
If you find errors in the present document, please send your comments to
the relevant service listed under Committee Support Staff.
If you find a security vulnerability in the present document, please report it through our
Coordinated Vulnerability Disclosure (CVD) program.
Notice of disclaimer & limitation of liability
The information provided in the present deliverable is directed solely to professionals who have the appropriate degree of
experience to understand and interpret its content in accordance with generally accepted engineering or
other professional standard and applicable regulations.
No recommendation as to products and services or vendors is made or should be implied.
No representation or warranty is made that this deliverable is technically accurate or sufficient or conforms to any law
and/or governmental rule and/or regulation and further, no representation or warranty is made of merchantability or fitness
for any particular purpose or against infringement of intellectual property rights.
In no event shall ETSI be held liable for loss of profits or any other incidental or consequential damages.

Any software contained in this deliverable is provided "AS IS" with no warranties, express or implied, including but not
limited to, the warranties of merchantability, fitness for a particular purpose and non-infringement of intellectual property
rights and ETSI shall not be held liable in any event for any damages whatsoever (including, without limitation, damages
for loss of profits, business interruption, loss of information, or any other pecuniary loss) arising out of or related to the use
of or inability to use the software.
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2026.
All rights reserved.
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 2 ETSI TS 128 554 V16.19.0 (2026-02)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations
pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be
found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to
ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the
ETSI IPR online database.
Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,
including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not
referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,
essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its
Members. 3GPP™, LTE™ and 5G™ logo are trademarks of ETSI registered for the benefit of its Members and of the
3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of ®
the oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.
Legal Notice
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities. These shall be
interpreted as being references to the corresponding ETSI deliverables.
The cross reference between 3GPP and ETSI identities can be found at 3GPP to ETSI numbering cross-referencing.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 3 ETSI TS 128 554 V16.19.0 (2026-02)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 6
1 Scope . 7
2 References . 7
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 7
4 End to end KPI concept and overview . 8
5 KPI definitions template . 8
6 End to end KPI definitions . 9
6.1 KPI Overview . 9
6.2 Accessibility KPI . 9
6.2.1 Mean registered subscribers of network and network slice through AMF . 9
6.2.2 Registered subscribers of network through UDM . 9
6.2.3 Registration success rate of one single network slice . 9
6.2.4 DRB Accessibility for UE services . 10
6.2.5 PDU session Establishment success rate of one network slice (S-NSSAI) . 10
6.3 Integrity KPI . 10
6.3.1 Latency and delay of 5G networks . 10
6.3.1.0 Void. 10
6.3.1.1 Downlink latency in gNB-DU. 10
6.3.1.2 Integrated downlink delay in RAN . 11
6.3.1.2.1 Downlink delay in NG-RAN for a sub-network . 11
6.3.1.2.2 Downlink delay in NG-RAN for a network slice subnet . 11
6.3.1.3 Downlink delay in gNB-DU . 12
6.3.1.3.1 Downlink delay in gNB-DU for a NRCellDU . 12
6.3.1.3.2 Downlink delay in gNB-DU for a sub-network . 12
6.3.1.3.3 Downlink delay in gNB-DU for a network slice subnet . 13
6.3.1.4 Downlink delay in gNB-CU-UP . 13
6.3.1.4.1 Downlink delay in gNB-CU-UP . 13
6.3.1.4.2 Downlink delay in gNB-CU-UP for a sub-network . 13
6.3.1.4.3 Downlink delay in gNB-CU-UP for a network slice subnet . 14
6.3.1.5 Uplink delay in gNB-DU . 14
6.3.1.5.1 Uplink delay in gNB-DU for a NR cell . 14
6.3.1.5.2 Uplink delay in gNB-DU for a sub-network . 15
6.3.1.5.3 Uplink delay in gNB-DU for a network slice subnet . 15
6.3.1.6 Uplink delay in gNB-CU-UP . 16
6.3.1.6.1 Uplink delay in gNB-CU-UP . 16
6.3.1.6.2 Uplink delay in gNB-CU-UP for a sub-network . 16
6.3.1.6.3 Uplink delay in gNB-CU-UP for a network slice subnet . 17
6.3.1.7 Integrated uplink delay in RAN . 17
6.3.1.7.1 Uplink delay in NG-RAN for a sub-network . 17
6.3.1.7.2 Uplink delay in NG-RAN for a network slice subnet . 18
6.3.1.8 E2E delay for network slice . 18
6.3.1.8.1 Average e2e uplink delay for a network slice . 18
6.3.1.8.2 Average e2e downlink delay for a network slice . 19
6.3.2 Upstream throughput for network and Network Slice Instance . 19
6.3.3 Downstream throughput for Single Network Slice Instance . 19
6.3.4 Upstream Throughput at N3 interface . 20
6.3.5 Downstream Throughput at N3 interface . 20
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 4 ETSI TS 128 554 V16.19.0 (2026-02)
6.3.6 RAN UE Throughput . 20
6.3.6.1 Void. 20
6.3.6.2 RAN UE Throughput definition . 20
6.3.6.3 DL RAN UE throughput . 21
6.3.6.3.1 DL RAN UE throughput for a NRCellDU . 21
6.3.6.3.2 DL RAN UE throughput for a sub-network . 21
6.3.6.3.3 DL RAN UE throughput for a network slice subnet. 22
6.3.6.4 UL RAN UE throughput . 22
6.3.6.4.1 UL RAN UE throughput for a NRCellDU . 22
6.3.6.4.2 UL RAN UE throughput for a sub-network . 23
6.3.6.4.3 UL RAN UE throughput for a network slice subnet. 23
6.4 Utilization KPI . 23
6.4.1 Mean number of PDU sessions of network and network Slice Instance . 23
6.4.2 Virtualised Resource Utilization of Network Slice Instance . 24
6.4.3 PDU session establishment time of network slice . 24
6.4.4 Mean number of successful periodic registration updates of Single Network Slice . 24
6.5 Retainability KPI . 25
6.5.1 QoS flow Retainability . 25
6.5.1.1 Definition . 25
6.5.1.2 Extended definition . 26
6.5.2 DRB Retainability . 26
6.5.2.1 Definition . 26
6.5.2.2 Extended definition . 26
6.6 Mobility KPI . 27
6.6.1 NG-RAN handover success rate . 27
6.6.2 Mean Time of Inter-gNB handover Execution of Network Slice . 27
6.6.3 Successful rate of mobility registration updates of Single Network Slice . 27
6.6.4 5GS to EPS handover success rate . 27
6.7 Energy Efficiency (EE) KPI . 28
6.7.1 NG-RAN data Energy Efficiency (EE) . 28
6.7.1.1 Definition . 28
Annex A (informative): Use cases for end to end KPIs . 29
A.1 Use case for end-to-end latency measurements of 5G network-related KPI . 29
A.2 Use case for number of registered subscribers of single network-slice related KPI . 29
A.3 Use case for upstream/downstream throughput for one-single-network-slice-related KPI . 29
A.4 Use case for mean PDU sessions number in network slice . 29
A.5 Use case for virtualised resource utilization of network-slice-related KPI . 30
A.6 Use case for 5GS registration success rate of one single-network-slice-related KPI . 30
A.7 Use case for RAN UE throughput-related KPI . 30
A.8 Use case for QoS flow retainability-related KPI . 30
A.9 Use case for DRB accessibility-related KPI . 30
A.10 Use case for mobility KPIs . 31
A.11 Use case for DRB retainability related KPI . 31
A.12 Use case for PDU session establishment success rate of one network slice (S-NSSAI) related KPI . 31
A.13 Use case for integrated downlink latency in RAN . 31
A.14 Use case for PDU session Establishment success rate of one single-network-slice instance-related
KPI . 32
A.15 Use case for QoS flow retainability-related KPI . 32
A.16 Use case for 5G Energy Efficiency (EE) KPI . 32
Annex B (informative): Change history . 34
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 5 ETSI TS 128 554 V16.19.0 (2026-02)
History . 36

ETSI
3GPP TS 28.554 version 16.19.0 Release 16 6 ETSI TS 128 554 V16.19.0 (2026-02)
Foreword
This Technical Specification has been produced by the 3rd Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 7 ETSI TS 128 554 V16.19.0 (2026-02)
1 Scope
The present document specifies end-to-end Key Performance Indicators (KPIs) for the 5G network and network slicing.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including
a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same
Release as the present document.
[1] 3GPP TR 21.905: "Vocabulary for 3GPP Specifications".
[2] Void.
[3] ITU-T Recommendation E.800: "Definitions of terms related to quality of service".
[4] 3GPP TS 24.501: " Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3".
[5] 3GPP TS 38.331: "NR; Radio Resource Control (RRC); Protocol specification".
[6] 3GPP TS 28.552: "Management and orchestration; 5G performance measurements".
[7] 3GPP TS 23.501: " System Architecture for the 5G System; Stage 2".
[8] ETSI ES 203 228 V1.2.1 (2017-04): "Environmental Engineering (EE); Assessment of mobile
network energy efficiency".
[9] 3GPP TS 28.310: "Management and orchestration; Energy efficiency of 5G".
[10] 3GPP TS 37.340: "Evolved Universal Terrestrial Radio Access (E-UTRA) and NR; Multi-
connectivity; Overall Description; Stage 2".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in TR 21.905 [1] and the following apply. A
term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An
abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in
TR 21.905 [1].
EE Energy Efficiency
kbit kilobit (1000 bits)
RTT Round Trip Time
EN-DC E-UTRA-NR Dual Connectivity
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 8 ETSI TS 128 554 V16.19.0 (2026-02)
4 End to end KPI concept and overview
The following KPI categories are included in the present document:
- Accessibility (see the definition in ITU-T Recommendation E.800 [3]).
- Integrity (see the definition in ITU-T Recommendation E.800 [3]).
- Utilization.
- Retainability (see the definition in ITU-T Recommendation E.800 [3]).
- Mobility.
- Energy Efficiency.
5 KPI definitions template
a) Name (Mandatory): This field shall contain the name of the KPI.
b) Description (Mandatory): This field shall contain the description of the KPI.
Within this field it should describe if the KPI is focusing on network or user view. This filed should also describe
the logical KPI formula to derive the KPI. For example, a success rate KPI’s logical formula is the number of
successful events divided by all events. This field should also show the KPI unit (e.g., kbit/s, millisecond) and
the KPI type (e.g., mean, ratio).
The KPI type can be one of the following:
- MEAN: This KPI is produced to reflect a mean measurement value based on a number of sample results.
- RATIO: This KPI is produced to reflect the percentage of a specific case occurrence to all the cases.
- CUM: This KPI is produced to reflect a cumulative measurement which is always increasing.
The KPI unit can be one of the following:
- percentage;
- time interval (second or millisecond or microsecond);
- Integer;
- kbit/s.
c) Formula definition (Optional):
This field should contain the KPI formula using the 3GPP defined measurement names.
This field can be used only when the measurement(s) needed for the KPI formula are defined in TS for
performance measurements (TS 28.552 [6]). This field shall clarify how the aggregation shall be done, for the
KPI object level(s) defined in d).
d) KPI Object (Mandatory):
This field shall contain the DN of the object instance where the KPI is applicable, including the object where the
measurement is made. The DN identifies one object instance of the following IOC:
- NetworkSliceSubnet.
- SubNetwork.
- NetworkSlice.
- NRCellDU.
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 9 ETSI TS 128 554 V16.19.0 (2026-02)
- NRCellCU.
e) Remark (Optional):
This field is for additional information required for the KPI definition, e.g. the definition of a call in UTRAN.
6 End to end KPI definitions
6.1 KPI Overview
The KPI categories defined in ITU-T Recommendation E.800 [3] will be reused by the present document.
6.2 Accessibility KPI
6.2.1 Mean registered subscribers of network and network slice through
AMF
a) AMFMeanRegNbr.
b) This KPI describe the mean number of subscribers that are registered to a network slice instance. It is obtained
by counting the subscribers in AMF that are registered to a network slice instance. It is an Integer. The KPI type
is MEAN.
c) ������������� =∑ ��.��������������������.������.
���
d) SubNetwork, NetworkSlice.
6.2.2 Registered subscribers of network through UDM
a) UDMRegNbr.
b) This KPI describes the total number of subscribers that are registered to a network through UDM. It is
corresponding to the measurement RM.RegisteredSubUDMNbrMean that counts subscribers registered in UDM.
It is an Integer. The KPI type is MEAN.
c) UDMRegNbr = ∑ ��.�����������������������.
���
d) SubNetwork.
6.2.3 Registration success rate of one single network slice
a) RSR.
b) This KPI describes the ratio of the number of successfully performed registration procedures to the number of
attempted registration procedures for the AMF set which related to one single network slice and is used to
evaluate accessibility provided by the end-to-end network slice and network performance. It is obtained by
successful registration procedures divided by attempted registration procedures. It is a percentage. The KPI type
is RATIO.
c)
AMF.5GSRegisSucc.Type

Type
RSR = *100%
AMF.5GSRegisAtt.Type

Type
NOTE: Above measurements with subcounter .Type should be defined in TS 24.501 [4].
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 10 ETSI TS 128 554 V16.19.0 (2026-02)
d) NetworkSlice.
6.2.4 DRB Accessibility for UE services
a) DRB Accessibility.
b) This KPI describes the DRBs setup success rate, including the success rate for setting up RRC connection and
NG signalling connection. It is obtained as the succeess rate for RRC connection setup multiplied by the success
rate for NG signalling connection setup multiplied by the success rate for DRB setup. The success rate for RRC
connection setup and for NG signalling connection setup shall exclude setups with establishment cause mo-
Signalling [5]. It is a percentage. The KPI type is RATIO.
c) DRBAccessibility 5QI = (∑RRC.ConnEstabSucc.Cause/∑RRC.ConnEstabAtt.Cause) *
(∑UECNTXT.ConnEstabSucc.Cause/∑ UECNTXT.ConnEstabAtt.Cause) *
(DRB.EstabSucc.5QI/DRB.EstabAtt.5QI) * 100.
DRB Accessibility SNSSAI = (∑RRC.ConnEstabSucc.Cause/∑RRC.ConnEstabAtt.Cause) *
(∑UECNTXT.ConnEstabSucc.Cause/∑ UECNTXT.ConnEstabAtt.Cause) *
(DRB.EstabSucc.SNSSAI/DRB.EstabAtt.SNSSAI) * 100.
The sum over causes shall exclude the establishment cause mo-Signalling [5].
For KPI on SubNetwork level the measurement shall be the averaged over all NRCellCUs in the
SubNetwork.
d) SubNetwork, NRCellCU.
6.2.5 PDU session Establishment success rate of one network slice (S-
NSSAI)
a) PDUSessionEstSR.
b) This KPI describes the ratio of the number of successful PDU session establishment request to the number of
PDU session establishment request attempts for all SMF which related to one network slice (S-NSSAI) and is
used to evaluate accessibility provided by the end-to-end network slice and network performance. It is obtained
by the number of successful PDU session requests divided by the number of attempted PDU session requests. It
is a percentage. The KPI type is RATIO.
∑ ��.����������������������.������
���
c) ��������������� = ×100.
∑
��.���������������������.������
���
d) NetworkSlice.
6.3 Integrity KPI
6.3.1 Latency and delay of 5G networks
6.3.1.0 Void
6.3.1.1 Downlink latency in gNB-DU
a) DLLat_gNBDU.
b) This KPI describes the gNB-DU part of the packet transmission latency experienced by an end-user. It is used to
evaluate the gNB latency contribution to the total packet latency. It is the average (arithmetic mean) of the time
from reception of IP packet to gNB-DU until transmission of first part of that packet over the air interface, for a
packet arriving when there is no previous data in queue for transmission to the UE. It is a time interval (0.1 mS).
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 11 ETSI TS 128 554 V16.19.0 (2026-02)
The KPI type is MEAN. This KPI can optionally be split into KPIs per QoS level (mapped 5QI or QCI in EN-
DC architecture ) and per S-NSSAI.
c) DLLat_gNBDU = DRB.RlcSduLatencyDl
or optionally DLLat_gNBDU.QoS = DRB.RlcSduLatencyDl.QoS where QOS identifies the target QoS
quality of service class.
or optionally DLLat_gNBDU.SNSSAI = DRB.RlcSduLatencyDl.SNSSAI where SNSSAI identifies the S-
NSSAI.
d) NRCellDU.
6.3.1.2 Integrated downlink delay in RAN

6.3.1.2.1 Downlink delay in NG-RAN for a sub-network
a) DLDelay_NR_SNw.
b) This KPI describes the average packet transmission delay through the RAN part to the UE. It is used to evaluate
delay performance of NG-RAN in downlink for a sub-network. It is the weighted average packets delay from
reception of IP packet in gNB-CU-UP until the last part of an RLC SDU packet was received by the UE
according to received HARQ feedback information for UM mode or until the last part of an RLC SDU packet
was received by the UE according to received RLC ACK for AM mode. It is a time interval (0.1 ms). The KPI
type is MEAN. This KPI can optionally be split into KPIs per QoS level (mapped 5QI or QCI in EN-DC
architecture) and per S-NSSAI.
c) Below are the equations for average “Integrated downlink delay in RAN” for this KPI on SubNetwork level. The
“Integrated downlink delay in RAN” is the sum of average DL delay in gNB-CU-UP of the sub-network
(DLDelay_gNBCUUP_SNw) and the average DL delay in gNB-DU of the sub-network
(DLDelay_gNBDU_SNw):
DLDelay_NR_SNw = DLDelay_gNBCUUP_SNw + DLDelay_gNBDU_SNw.
or optionally DLDelay_ NR_SNw.QOS = DLDelay_gNBCUUP_SNw.QOS + DLDelay_gNBDU_SNw.QOS
where QOS identifies the target quality of service class.
or optionally DLDelay_NR_SNw.SNSSAI = DLDelay_gNBCUUP_SNw.SNSSAI +
DLDelay_gNBDU_SNw.SNSSAI where SNSSAI identifies the S-NSSAI.
d) SubNetwork.
6.3.1.2.2 Downlink delay in NG-RAN for a network slice subnet
a) DLDelay_NR_Nss.
b) This KPI describes the average packet transmission delay through the RAN part to the UE. It is used to evaluate
delay performance of NG-RAN in downlink for a network slice subnet. It is the weighted average packets delay
from reception of IP packet in gNB-CU-UP until the last part of an RLC SDU packet was received by the UE
according to received HARQ feedback information for UM mode or until the last part of an RLC SDU packet
was received by the UE according to received RLC ACK for AM mode. It is a time interval (0.1 ms). The KPI
type is MEAN.
c) Below is the equation for average "Integrated downlink delay in RAN" for this KPI on NetworkSliceSubnet
level. The "Integrated downlink delay in RAN" for network slice subnet is the sum of average DL delay in gNB-
CU-UP of the network slice subnet (DLDelay_gNBCUUP_Nss) and the average DL delay in gNB-DU of the
network slice subnet (DLDelay_gNBDU_Nss):
DLDelay_NR_Nss.SNSSAI = DLDelay_gNBCUUP_Nss.SNSSAI + DLDelay_gNBDU_Nss.SNSSAI where
SNSSAI identifies the S-NSSAI that the network slice subnet supports.
d) NetworkSliceSubnet.
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 12 ETSI TS 128 554 V16.19.0 (2026-02)
6.3.1.3 Downlink delay in gNB-DU
6.3.1.3.1 Downlink delay in gNB-DU for a NRCellDU
a) DLDelay_gNBDU_Cell.
b) This KPI describes the average packet transmission delay through the gNB-DU part to the UE. It is used to
evaluate delay performance of gNB-DU in downlink. It is the average packets delay time from arrival of an RLC
SDU at the RLC ingress F1-U termination until the last part of an RLC SDU packet was received by the UE
according to received HARQ feedback information for UM mode or until the last part of an RLC SDU packet
was received by the UE according to received RLC ACK for AM mode. It is a Time interval (0.1 ms). The KPI
type is MEAN. This KPI can optionally be split into KPIs per QoS level (mapped 5QI or QCI in EN-DC
architecture) and per S-NSSAI.
c) Below is the equation for average DL delay in gNB-DU for a NRCellDU:
DLDelay_gNBDU_Cell = DRB.RlcSduDelayDl + DRB.AirIfDelayDl.
and optionally: DLDelay_gNBDU.QOS = DRB.RlcSduDelayDl.QOS + DRB.AirIfDelayDl.QOS where QOS
identifies the target quality of service class.
and optionally: DLDelay_gNB.SNSSAI = DRB.RlcSduDelayDl.SNSSAI + DRB.AirIfDelayDl.SNSSAI where
SNSSAI identifies the S-NSSAI.
d) NRCellDU.
6.3.1.3.2 Downlink delay in gNB-DU for a sub-network
a) DLDelay_gNBDU_SNw.
b) This KPI describes the average packet transmission delay through the gNB-DU part to the UE. It is used to
evaluate delay performance of gNB-DU in downlink for a sub-network. It is the weighted average packets delay
time from arrival of an RLC SDU at the RLC ingress F1-U termination until the last part of an RLC SDU packet
was received by the UE according to received HARQ feedback information for UM mode or until the last part of
an RLC SDU packet was received by the UE according to received RLC ACK for AM mode. It is a Time
interval (0.1 ms). The KPI type is MEAN. This KPI can optionally be split into KPIs per QoS level (mapped 5QI
or QCI in EN-DC architecture) and per S-NSSAI.
c) Below is the equation for average DL delay in gNB-DU for a sub-network, where
- W is the measurement for the weighted average, one of the following:
- the DL data volume of the NR cell;
- the number of UL user data packets of the NR cell;
- any other types of weight defined by the consumer of KPI
- the #NRCellDU is the number of NRCellDU’s in the SubNetwork.
#��������
∑ � ,
� ���.��� !"�#�$%�� & ���.’()*+�#�$%�� ∗-.
�
DLDelay_gNBDU_SNw =
#��������
∑ � ,
-
�
and optionally KPI on SubNetwork level per QoS and per S-NSSAI:
#��������
∑ �����.��� !"�#�$%��./�� & ���.’()*+�#�$%��./��,∗-./��.
�
DLDelay_gNBDU_SNw.��� =
#��������
∑ �-./��,
�
#��������
∑ �����.��� !"�#�$%��.������ & ���.’()*+�#�$%��.������,∗-.������.
�
DLDelay_gNBDU_SNw.������ =
#��������
∑ �-.������,
�
d) SubNetwork.
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 13 ETSI TS 128 554 V16.19.0 (2026-02)
6.3.1.3.3 Downlink delay in gNB-DU for a network slice subnet
a) DLDelay_gNBDU_Nss.
b) This KPI describes the average packet transmission delay through the gNB-DU part to the UE. It is used to
evaluate delay performance of gNB-DU in downlink for a network slice subnet. It is the weighted average
packets delay time from arrival of an RLC SDU at the RLC ingress F1-U termination until the last part of an
RLC SDU packet was received by the UE according to received HARQ feedback information for UM mode or
until the last part of an RLC SDU packet was received by the UE according to received RLC ACK for AM
mode. It is a Time interval (0.1 ms). The KPI type is MEAN.
c) Below is the equation for average DL delay in gNB-DU for a network slice subnet, where
- W is the measurement for the weighted average, one of the following:
- the DL data volume of the NR cell;
- the number of DL user data packets of the NR cell;
- any other types of weight requested by the consumer of KPI;
- the #NRCellDU is the number of NRCellDU’s associated with the NetworkSliceSubnet.
#��������
∑ �����.��� !"�#�$%��.������ & ���.’()*+�#�$%��.������,∗-.������.
�
DLDelay_gNBDU_Nss.������ =
#��������
∑ �-.������,
�
d) NetworkSliceSubnet.
6.3.1.4 Downlink delay in gNB-CU-UP
6.3.1.4.1 Downlink delay in gNB-CU-UP
a) DLDelay_gNBCUUP.
b) This KPI describes the average packet transmission delay through the gNB-CU-UP to the gNB-DU. It is used to
evaluate the delay performance of gNB-CU-UP in downlink. It is the average packets delay from reception of IP
packet in gNB-CU-UP until the time of arrival, at the gNB-DU, of the RLC SDU at the RLC ingress F1-U
termination. It is a Time interval (0.1 ms). The KPI type is MEAN. This KPI can optionally be split into KPIs
per QoS level (mapped 5QI or QCI in EN-DC architecture) and per S-NSSAI.
c) Below the equation for average DL delay in a gNB-CU-CP:
DLDelay_gNBCUUP = DRB. PdcpSduDelayDl + DRB.PdcpF1Delay
and optionally: DLDelay_ gNBCUUP.QOS = DRB.PdcpSduDelayDl.QOS + DRB.PdcpF1Delay.QOS
where QOS identifies the target quality of service class.
and optionally: DLDelay_gNBCUUP.SNSSAI = DRB.PdcpSduDelayDl.SNSSAI +
DRB.PdcpF1Delay.SNSSAI where SNSSAI identifies the S-NSSAI.
d) GNBCUUPFunction.
e) In non-split gNB scenario, the value of DRB.PdcpF1Delay (optionally DRB.PdcpF1Delay.QOS, and optionally
DRB.PdcpF1Delay.SNSSAI) is set to zero because there are no F1-interfaces in this scenario.
6.3.1.4.2 Downlink delay in gNB-CU-UP for a sub-network
a) DLDelay_gNBCUUP_SNw.
b) This KPI describes the average packet transmission delay through the gNB-CU-UP to the gNB-DU. It is used to
evaluate the delay performance of gNB-CU-UP in downlink for a sub-network. It is the weighted average
packets delay from reception of IP packet in gNB-CU-UP until the time of arrival, at the gNB-DU, of the RLC
SDU at the RLC ingress F1-U termination. It is a Time interval (0.1 ms). The KPI type is MEAN. This KPI can
optionally be split into KPIs per QoS level (mapped 5QI or QCI in EN-DC architecture) and per S-NSSAI.
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 14 ETSI TS 128 554 V16.19.0 (2026-02)
c) Below is the equation for average UL delay in gNB-CU-UP for a sub-network, where
- W is the measurement for the weighted average, one of the following:
- the DL data volume in gNB-CU-UP;
- the number of DL user data packets in gNB-CU-UP;
- any other types of weight requested by the consumer of KPI;
- the # GNBCUUPFunctions is the number of GNBCUUPFunctions’s in the SubNetwork.
#���������������
∑ �����.0!�1 !"�#�$%�� & ���.0!�123�#�$%,∗-.
�
DLDelay_gNBCUUP_SNw =
#���������������
∑ �-,
�
and optionally KPI on SubNetwork level per QoS and per S-NSSAI:
#���������������
∑ �����.0!�1 !"�#�$%��./�� & ���.0!�123�#�$%.45 ,∗-./��.
�
DLDelay_gNBCUUP_SNw.��� =
#���������������
∑ �-./��,
�
#���������������
∑ �����.0!�1 !"�#�$%��.������ & ���.0!�123�#�$%.������,∗-.������.
�
DLDelay_gNBCUUP_SNw.������ =
#���������������
∑ �-.������,
�
d) SubNetwork
e) In non-split gNB scenario, the value of DRB.PdcpF1Delay (optionally DRB.PdcpF1Delay.QOS, and optionally
DRB.PdcpF1Delay.SNSSAI) is set to zero because there are no F1-interfaces in this scenario.
6.3.1.4.3 Downlink delay in gNB-CU-UP for a network slice subnet
a) DLDelay_gNBCUUP_Nss.
b) This KPI describes the average packet transmission delay through the gNB-CU-UP to gNB-DU. It is used to
evaluate the delay performance of gNB-CU-UP in downlink for a network slice subnet. It is the weighted
average packets delay from reception of IP packet in gNB-CU-UP until the time of arrival, at the gNB-DU, of
the RLC SDU at the RLC ingress F1-U termination. It is a Time interval (0.1 ms). The KPI type is MEAN.
c) Below is the equation for average UL delay in gNB-CU-UP for a network slice subnet, where
- W is the measurement for the weighted average, one of the following:
- the DL data volume in gNB-CU-UP;
- the number of DL user data packets in gNB-CU-UP;
- any other types of weight requested by the consumer of KPI;
- the # GNBCUUPFunctions is the number of GNBCUUPFunctions’s associated with the
NetworkSliceSubnet.
#���������������
∑ �����.0!�1 !"�#�$%��.������ & ���.0!�123�#�$%.������,∗-.������.
�
DLDelay_gNBCUUP_Nss.������ =
#���������������
∑ �-.������,
�
d) NetworkSliceSubnet
e) In non-split gNB scenario, the value of DRB.PdcpF1Delay.SNSSAI is set to zero because there are no F1-
interfaces in this scenario.
6.3.1.5 Uplink delay in gNB-DU
6.3.1.5.1 Uplink delay in gNB-DU for a NR cell
a) ULDelay_gNBDU_Cell.
b) This KPI describes the average packet transmission delay through the gNB-DU part from the UE in a NR cell. It
is used to evaluate delay performance of gNB-DU in uplink. It is the average packet delay from when an UL
ETSI
3GPP TS 28.554 version 16.19.0 Release 16 15 ETSI TS 128 554 V16.19.0 (2026-02)
RLC SDU was scheduled, as per the scheduling grant provided, until time when the RLC SDU is sent to PDCP
or CU for split gNB. It is a time interval (0.1 ms). The KPI type is MEAN. This KPI can optionally be split into
KPIs per QoS level (mapped 5QI or QCI in EN-DC architecture) and per S-NSSAI.
c) Below is the equation for average UL delay in gNB-DU for a NRCellDU:
ULDelay_gNBDU_Cell = DRB.RlcDelayUI + DRB.AirIfDelayUI
and optionally: ULDelay_gNBDU.��� = DRB. RlcDelayUl.��� + DRB. AirIfDelayUl.��� where QOS
identifies the target quality of service class.
and optionally: ULDelay_gNBDU.������ = DRB. RlcDelayUl.������ + DRB. AirIfDelayUl.������
where SNSSAI identifies the S-NSSAI.
d) NRCellDU.
6.3.1.5.2 Uplink delay in gNB-DU for a sub-network
a) ULDelay_gNBDU_SNw.
b) This KPI describ
...