ETSI TR 103 827 V1.1.1 (2023-09)

SmartM2M; SAREF: Digital Twins opportunities for the Ontology Context

DTR/SmartM2M-103827

General Information

• Status: Not Published
• Technical Committee: SmartM2M - Smart M2M
• Current Stage: 12 - Completion
• Due Date: 30-Sep-2023
• Completion Date: 26-Sep-2023

Standards Content (Sample)

TECHNICAL REPORT
SmartM2M;
SAREF: Digital Twins opportunities for the Ontology Context

2 ETSI TR 103 827 V1.1.1 (2023-09)

Reference
DTR/SmartM2M-103827
Keywords
artificial intelligence, digital twins, interoperability,
IoT, IoT platforms, oneM2M, ontology, SAREF,
semantic, Smart Cities
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:
https://www.etsi.org/standards-search
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 at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
If you find a security vulnerability in the present document, please report it through our
Coordinated Vulnerability Disclosure Program:
https://www.etsi.org/standards/coordinated-vulnerability-disclosure
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
rule and/or regulation and further, no representation or warranty is made of merchantability or fitness
and/or governmental
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 2023.
All rights reserved.
ETSI
3 ETSI TR 103 827 V1.1.1 (2023-09)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 4
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definition of terms, symbols and abbreviations . 11
3.1 Terms . 11
3.2 Symbols . 11
3.3 Abbreviations . 11
4 Digital Twins Landscape for the Urban domain . 12
5 Digital Twins and Ontologies . 13
5.1 Introduction . 13
5.2 Standards for Digital Twins. 15
5.3 Usage of Ontologies for Digital Twins . 18
6 Urban Digital Twins Use Cases . 19
6.1 UC1: Rome, Rinascimento III Area . 19
6.2 UC2: West Cambridge Campus . 20
6.3 UC3: City of Sofia . 20
6.4 UC4: Digital Twin Victoria . 21
6.5 UC5: Smart Construction Digital Twin . 21
6.6 UC6: Interoperable Urban Digital Twins . 22
7 Analysis of SAREF with respect to the Urban Digital Twin context . 23
7.1 Introduction . 23
7.2 Analysis of SAREF Core . 23
7.3 Analysis of SAREF Extensions . 24
8 Conclusion . 29
History . 30

ETSI
4 ETSI TR 103 827 V1.1.1 (2023-09)
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 Web server (https://ipr.etsi.org/).
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™ and LTE™ 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.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Smart Machine-to-Machine
communications (SmartM2M).
Modal verbs terminology
In the present document "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.
Introduction
In an increasingly interconnected and technology-driven world, the concept of Digital Twins (DTs) has emerged as a
powerful tool in various domains. Among these domains, the urban landscape stands out as a fascinating and complex
environment where DTs have immense potential. A Digital Twin (DT) refers to a virtual representation of a physical
entity, such as a building, infrastructure, or even an entire city, that is synchronized and connected in real-time with its
physical counterpart. In the urban domain, DTs offer a transformative approach to urban planning, development, and
management. By leveraging advanced technologies like the Internet of Things (IoT), Artificial Intelligence (AI), big
data analytics, and cloud computing, DTs enable a comprehensive understanding of urban systems and facilitate
data-driven decision-making.
ETSI
5 ETSI TR 103 827 V1.1.1 (2023-09)
DTs for the urban domain go beyond traditional 2D maps and static models by incorporating real-time data streams
from sensors, cameras, and other devices embedded throughout the city. These data streams provide a continuous flow
of information on various aspects of urban life, including traffic patterns, energy consumption, air quality, infrastructure
health, and social dynamics. By capturing and analysing this wealth of data, DTs create dynamic, virtual replicas that
mirror the behaviour and characteristics of the physical urban environment. One of the key benefits of DTs in the urban
domain is their ability to simulate and predict outcomes. Urban planners, architects, and policymakers can use DTs to
model different scenarios and assess the potential impact of changes in the urban landscape before implementing them.
This predictive capability helps optimize resource allocation, enhance sustainability, improve infrastructure design, and
ultimately create more liveable and efficient cities.
Furthermore, DTs enable enhanced situational awareness and real-time monitoring. City officials and emergency
responders can use DTs to monitor critical infrastructure, detect anomalies, and respond swiftly to incidents or
emergencies. By integrating data from various sources, such as surveillance cameras, weather sensors, and social media
feeds, DTs provide a holistic view of the urban environment, fostering proactive and informed decision-making.
However, the adoption of DTs in the urban domain comes with challenges. Ensuring data privacy and security,
managing the complexity of integrating diverse data sources, addressing interoperability issues, and gaining public trust
are some of the hurdles that need to be overcome. Additionally, the scalability and sustainability of DT ecosystems
require careful consideration to ensure their long-term viability. Despite these challenges, DTs have the potential to
revolutionize urban planning and management. By harnessing the power of technology, these virtual replicas provide
invaluable insights, empower decision-makers, and enable the creation of more sustainable, resilient, and inclusive
cities. As urban populations continue to grow and cities face unprecedented challenges, DTs offer a promising pathway
towards a smarter and better-connected urban future.
The present document provides an analysis of the utilization of DTs in the urban field, with a specific emphasis on
interoperability. The adoption of existing standards and the utilization of semantic-based solutions have been surveyed
to determine their implementation. Furthermore, a comprehensive examination of the SAREF suite in relation to various
use cases is discussed together with the identification of the priority gaps that need to be addressed in the near future.

ETSI
6 ETSI TR 103 827 V1.1.1 (2023-09)
1 Scope
The present document provides an overview of the DT landscape for the urban domain. It is also discussed how the
DT domain has been addressed from the standard perspectives by presenting the existing ones by also including a
deeper overview about how ontologies have been employed to manage interoperability aspects. The present document
also lists a set of use cases is presented in order to depict concrete implementation of DTs to use as starting point for an
interoperability analysis. Finally, the present document provides preliminary insights about how the SAREF Core
ontology, and its extensions can be exploited to support interoperability aspects within the DTs domain.
2 References
2.1 Normative references
Normative references are not applicable in the present document.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] WorldBank, 2022.
[i.2] Caragliu, A., Del Bo, C., Nijkamp, P., 2013. Smart Cities in Europe. Routledge.
[i.3] Florida, R., Adler, P., Mellander, C., 2017. The city as innovation machine. Reg. Stud. 51 (1),
86-96.
[i.4] Lehtola, V.V., Ståhle, P., 2014. Societal innovation at the interface of the state and civil society.
Innov.: Eur. J. Soc. Sci. Res. 27 (2), 152-174.
[i.5] Calzada, I., 2020. Democratising smart cities? Penta-helix multistakeholder social innovation
framework. Smart Cities 3 (4), 1145-1172.
[i.6] Linde, L., Sjödin, D., Parida, V., Wincent, J., 2021. Dynamic capabilities for ecosystem
orchestration a capability-based framework for smart city innovation initiatives. Technol. Forecast.
Soc. Change 166, 120614.
[i.7] Negri, E., Fumagalli, L., Macchi, M.: "A review of the roles of digital twin in CPS-based
th
production systems". In: 27 International Conference on Flexible Automation and Intelligent
Manufacturing, FAIM2017, 27-30 June 2017, Modena, Italy, Vol. 11, pp. 939-948.
[i.8] Jones, D., Snider, C., Nassehi, A., Yon, J., Hicks, B., 2020: "Characterising the Digital Twin: A
systematic literature review", 29, 36-52.
[i.9] Greif, T., Stein, N., Flath, C.M., 2020: "Peeking into the void: Digital twins for construction site
logistics". Comput. Ind. 121, 103264.
[i.10] Deng, M., Menassa, C.C., Kamat, V.R., 2021: "From BIM to digital twins: a systematic review of
the evolution of intelligent building representations in the AEC-FM industry". J. Inf. Technol.
Constr. 26, 58-83.
[i.11] Wong, J.K.W., Ge, J., He, S.X., 2018: "Digitisation in facilities management: A literature review
and future research directions". Autom. Constr. 92, 312-326.
ETSI
7 ETSI TR 103 827 V1.1.1 (2023-09)
[i.12] Matarneh, S.T., Danso-Amoako, M., Al-Bizri, S., Gaterell, M., Matarneh, R., 2019: "Building
information modeling for facilities management: A literature review and future research
directions". J. Build. Eng. 24, 100755.
[i.13] Errandonea, I., Beltrán, S., Arrizabalaga, S., 2020: "Digital Twin for maintenance: A literature
review". Comput. Ind. 123, 103316.
[i.14] Ketzler, B., Naserentin, V., Latino, F., Zangelidis, C., Thuvander, L., Logg, A., 2020: "Digital
twins for cities: A state of the art review". Built Environ. 46 (4), 547-573.
[i.15] Farsi, M., Daneshkhah, A., Hosseinian-Far, A., Jahankhani, H., et al., 2020: "Digital Twin
Technologies and Smart Cities". Springer.
[i.16] D'Hauwers, R., Walravens, N., Ballon, P., 2021: "From an inside-in towards an outside-out urban
digital twin: Business models and implementation challenges". ISPRS Ann. Photogramm., Remote
Sens. Spatial Inf. Sci. VIII-4/W1-2021, 25-32.
[i.17] Ruohomäki, T., Airaksinen, E., Huuska, P., Kesäniemi, O., Martikka, M., Suomisto, J., 2018:
"Smart city platform enabling digital twin". In: 2018 International Conference on Intelligent
Systems (IS). IEEE, pp. 155-161.
[i.18] Schrotter, G., Hürzeler, C., 2020: "The digital twin of the city of Zurich for urban planning".
PFG-J. Photogramm., Remote Sens. Geoinformation Sci. 88 (1), 99-112.
[i.19] Lehner, H., Dorffner, L., 2020: "Digital geotwin vienna: Towards a digital twin city as geodata
hub".
[i.20] Van der Valk, H., Haße, H., Möller, F., Arbter, M., Henning, J.-L., Otto, B., 2020: "A taxonomy of
digital twins". In: AMCIS 2020 Proceedings. 4.
[i.21] Grieves, M.: "Digital twin: Manufacturing excellence through virtual factory replication". White
Paper 1, 1-7 (2014).
[i.22] Grieves, M., Vickers, J.: "Digital twin: Mitigating unpredictable, undesirable emergent behavior in
complex systems". In: Transdisciplinary Perspectives on Complex Systems, pp. 85-113. Springer
(2017).
[i.23] Qi, Q., Tao, F., Hu, T., Anwer, N., Liu, A., Wei, Y., Wang, L., Nee, A.Y.: "Enabling Technologies
and Tools for Digital Twin". Journal of Manufacturing Systems (2019).
[i.24] Borodulin, K., Radchenko, G., Shestakov, A., Sokolinsky, L., Tchernykh, A., Prodan, R.:
"Towards digital twins cloud platform: Microservices and computational workflows to rule a smart
factory". In: Proceedings of the10th International Conference on Utility and Cloud Computing.
pp. 209-210 (2017).
[i.25] Duarte, B.B., de Castro Leal, A.L., de Almeida Falbo, R., Guizzardi, G., Guizzardi, R.S., Souza,
V.E.S.: "Ontological foundations for software requirements with a focus on requirements at
runtime". Applied Ontology 13(2), 73-105 (2018).
[i.26] Fonseca, C.M., Almeida, J.P.A., Guizzardi, G., Carvalho, V.A.: "Multi-level conceptual modeling:
Theory, language and application". Data & Knowledge Engineering 134, 101894 (2021).
[i.27] Guizzardi, G., Almeida, J.P.A., Guarino, N., de Carvalho, V.A.: "Towards an ontological analysis
of powertypes". In: JOWO@ IJCAI (2015).
[i.28] ISO 23247-1:2021: "Automation systems and integration -- Digital twin framework for
manufacturing -- Part 1: Overview and general principles".
[i.29] Draft Recommendation ITU-T Y.scdt-reqts TD2480. 2021: "Requirements and capabilities of a
digital twin system for smart cities".
[i.30] ISO/IEC AWI 30173: "Digital twin -- Concepts and terminology".
[i.31] ISO 23247-2:2021: "Automation systems and integration -- Digital Twin framework for
manufacturing -- Part 2: Reference architecture".
ETSI
8 ETSI TR 103 827 V1.1.1 (2023-09)
[i.32] IEC 62832-1:2020: "Industrial-process measurement, control and automation -- Digital Factory
framework -- Part 1: General principles".
TM
-1997-2010: "IEEE Standard for a Smart Transducer Interface for Sensors and
[i.33] IEEE 1451
Actuators".
[i.34] Recommendation ITU-T Y.4473 (2020): "Sensor Things API -- Sensing".
TM
[i.35] IEEE 2888.1: "Specification of Sensor Interface for Cyber and Physical World".
TM
[i.36] IEEE 2888.2: "Standard for Actuator Interface for Cyber and Physical World".
[i.37] IEC 63278-1 (Ed. 1): "Asset administration shell (AAS) for industrial applications --
Part 1: Administration shell structure".
[i.38] ISO 23247:2021: "Automation systems and integration -- Digital Twin framework for
manufacturing".
[i.39] ISO 23247-3:2021: "Automation systems and integration -- Digital Twin framework for
manufacturing -- Part 3: Digital representation of manufacturing elements".
[i.40] ISO 10303 (1994-2021): "Industrial automation systems and integration -- Product data
representation and exchange".
[i.41] IEC 62264 (2013-2016): "Enterprise-control system integration".
[i.42] IEC 62714 (2015-2010): "Engineering data exchange format for use in industrial automation
systems engineering -- Automation Markup Language".
[i.43] IEC 13399 (2006-2016): "Cutting tool data representation and exchange".
TM
[i.44] IEEE P2806.1 : "Standard for Connectivity Requirements of Digital Representation for Physical
Objects in Factory Environments".
[i.45] ISO/IEC guide-77 (2008): "Guide for specification of product properties and classes".
[i.46] ISO 13584 (1998-2010): "Industrial automation systems and integration -- Parts library".
[i.47] IEC 61360-1:2017: "Standard data element types with associated classification scheme --
Part 1: Definitions -- Principles and methods".
[i.48] ISO/TS 29002 (2009-2010): "Industrial automation systems and integration -- Exchange of
characteristic data".
[i.49] IEC 61987 (2006-2018): "Industrial-process measurement and control -- Data structures and
elements in process equipment catalogues".
TM
[i.50] IEEE 2888.3 : "Orchestration of Digital Synchronization between Cyber and Physical World".
[i.51] OPCUA 10000 (2017-2021): "OPC Unified Architecture Specification".
TM
[i.52] IEEE 802.3-2018 : "IEEE Standard for Ethernet".
[i.53] IEC 61158 (2003-2019) (all parts): "IEC standards for Fieldbus and Real Time Ethernet".
[i.54] IEC 61784-2:2019: "Industrial communication networks -- Profiles -- Part 2: Additional fieldbus
profiles for real-time networks based on ISO/IEC/IEEE 8802-3".
[i.55] IEC 62591:2016: "Industrial networks -- Wireless communication network and communication
profiles -- wireless TM".
[i.56] IEC 62601:2015: "Industrial networks -- Wireless communication network and communication
profiles -- WIA-PA".
[i.57] IEC 62734:2019: "Industrial networks -- Wireless communication network and communication
profiles -- ISA 100.11a".
ETSI
9 ETSI TR 103 827 V1.1.1 (2023-09)
[i.58] IEC 62948:2017: "Industrial networks -- Wireless communication network and communication
profiles -- WIA-FA".
[i.59] IEC 62657-1:2017: "Industrial communication networks -- Wireless communication networks --
Part 1: Wireless communication requirements and spectrum considerations".
[i.60] 5G-ACIA White Paper (2021): "Integration of 5G with Time-Sensitive Networking for Industrial
Communications".
[i.61] Draft new Recommendation ITU-T Y.DTN-ReqArch TD4057 (2021): "Requirements and
Architecture of Digital Twin Network".
[i.62] Draft new Recommendation ITU-T X.sg-dtn TD 4057 (2021): "Requirements and Architecture of
Digital Twin Network".
[i.63] ISO 23247-4:2020: "Automation systems and integration -- Digital Twin framework for
manufacturing -- Part 4: Information exchange".
TM
[i.64] IEEE 2888.4 : "Architecture for Virtual Reality Disaster Response Training System with Six
degrees of Freedom (6 DoF)".
[i.65] Recommendation ITU-T Y.dt-smartfirefighting TD2477-R1 (2021): "Requirements and capability
framework of digital twin for smart firefighting".
[i.66] ISO 13372:2004: "Condition monitoring and diagnostics of machines -- Vocabulary".
[i.67] ISO 17359:2003: "Condition monitoring and diagnostics of machines -- General guidelines".
TM
[i.68] IEEE 1671-2006 : "IEEE Trial-Use Standard for Automatic Test Markup Language (ATML) for
Exchanging Automatic Test Equipment and Test Information via XML".
TM
: "IEEE Guide for the Use of Artificial Intelligence Exchange and Service Tie
[i.69] IEEE 1232.3-2014
to All Test Environments (AI-ESTATE)".
TM
[i.70] IEEE 1904.1-2013 : "IEEE Standard for Conformance Test Procedures for Service
Interoperability in Ethernet Passive Optical Networks".
[i.71] ISO 20242-3:2011: "Industrial automation systems and integration -- Service interface for testing
applications -- Part 3: Virtual device service interface".
[i.72] ISO 20242-4:2011: "Industrial automation systems and integration -- Service interface for testing
applications -- Part 4: Device capability profile template".
[i.73] ISO/IEC 14393:1996: "Information technology -- Test methods for measuring conformance to
directory services -- Application Program Interface (API) (Language independent)".
[i.74] Recommendation ITU-T E.800 (2008): "Definitions of terms related to quality of service".
[i.75] Recommendation ITU-T G.1010 (2001-2004): "End-user multimedia QoS categories".
[i.76] Recommendation ITU-T G.1000 (2002): "Communications Quality of Service: A framework and
definitions".
[i.77] Recommendation ITU-T E.802 (2007): "Framework and methodologies for the determination and
application of QoS parameters".
[i.78] Gruber, T. R.: "A translation approach to portable ontology specifications". Knowledge
acquisition, 5(2), 199-220 (1993).
[i.79] De Nicola, A., Missikoff, M.: "A lightweight methodology for rapid ontology engineering".
Communications of the ACM, 59(3), 79-86 (2016).
[i.80] Falquet, G., Metral, C., Teller, J., Tweed, C.: "Ontologies in urban development projects".
London: Springer (2005).
[i.81] Falquet, G., Métral, C., Teller, J., Tweed, C., Métral, C., Cutting-Decelle, A. F.: "Ontologies for
interconnecting urban models". Ontologies in Urban Development Projects, 105-122 (2011).
ETSI
10 ETSI TR 103 827 V1.1.1 (2023-09)
[i.82] De Nicola, A., Villani, M. L.: "Smart city ontologies and their applications: a systematic literature
review". Sustainability, 13(10), 5578 (2021).
[i.83] da Silva Mendonça, R., de Oliveira Lins, S., de Bessa, I.V., de Carvalho Ayres, F.A., de Medeiros,
R.L.P., de Lucena, V.F.: "Digital twin applications: A survey of recent advances and challenges".
Processes 10 (4) (2022).
[i.84] Fuller, A., Fan, Z., Day, C., Barlow, C.: "Digital twin: Enabling technologies, challenges and open
TM
research". IEEE Access 8, 108952-108971 (2020).
[i.85] Yu, G., Wang, Y., Mao, Z., Hu, M., Sugumaran, V., Wang, Y. K.: "A digital twin-based decision
analysis framework for operation and maintenance of tunnels". Tunnelling and Underground
Space Technology, 116, 104125 (2021).
[i.86] Van Den Brand, M., Cleophas, L., Gunasekaran, R., Haverkort, B., Negrin, D. A. M., Muctadir, H.
M.: Models meet data: "Challenges to create virtual entities for digital twins". In 2021 ACM/IEEE
International Conference on Model Driven Engineering Languages and Systems Companion
TM
(MODELS-C) (pp. 225-228). IEEE . (2021).
[i.87] Ladj, A., Wang, Z., Meski, O., Belkadi, F., Ritou, M., Da Cunha, C.: "A knowledge-based Digital
Shadow for machining industry in a Digital Twin perspective". Journal of Manufacturing Systems,
58, 168-179 (2021).
[i.88] Rodrigo, M. S., Rivera, D., Moreno, J. I., Álvarez-Campana, M., & López, D. R.: Digital Twins
TM
for 5G Networks: "A modeling and deployment methodology". IEEE Access (2023).
[i.89] ABADI, M., Chaimae, A. B. A. D. I., Asmae, A. B. A. D. I., Hussain, B. A.: "A Smart Decision
Making System for the Selection of Production Parameters using Digital Twin and Ontologies".
International Journal of Advanced Computer Science and Applications, 13(2) (2022).
[i.90] Nilsson, J., Sandin, F., Delsing, J.: "Interoperability and machine-to-machine translation model
TM th
with mappings to machine learning tasks". In 2019 IEEE 17 International Conference on
TM
Industrial Informatics (INDIN) (Vol. 1, pp. 284-289). IEEE (2019).
[i.91] Austin, M., Delgoshaei, P., Coelho, M., Heidarinejad, M.: "Architecting smart city digital twins:
Combined semantic model and machine learning approach". Journal of Management in
Engineering, 36(4), 04020026 (2020).
[i.92] Dimitrov, H., Petrova-Antonova, D.: "3D city model as a first step towards digital twin of Sofia
city". International archives of the photogrammetry, remote sensing and spatial information
sciences, XLIII-B4-2021, 23-30 (2021).
[i.93] ISO 19650-1:2018: "Organization and digitization of information about buildings and civil
engineering works, including building information modelling (BIM) -- Information management
using building in formation modelling -- Part 1: Concepts and principles".
[i.94] Grieves, M., Vickers, J. (2016): "Origins of the Digital Twin Concept".
[i.95] ETSI TS 103 264 (V3.1.1): "SmartM2M; Smart Applications; Reference Ontology and
oneM2M Mapping".
[i.96] ETSI TS 103 410-3 (V1.1.2): "SmartM2M; Extension to SAREF; Part 3: Building Domain".
[i.97] ETSI TS 103 410-11 (V1.1.1): "SmartM2M; Extension to SAREF; Part 11: Lift Domain".
[i.98] ETSI TS 103 410-7 (V1.1.1): "SmartM2M; Extension to SAREF; Part 7: Automotive Domain".
[i.99] ETSI TS 103 410-2 (V1.1.2): "SmartM2M; Extension to SAREF; Part 2: Environment Domain".
[i.100] ETSI TS 103 410-4 (V1.1.2): "SmartM2M; Extension to SAREF; Part 4: Smart Cities Domain".
[i.101] ETSI TS 103 410-1 (V1.1.2): "SmartM2M; Extension to SAREF; Part 1: Energy Domain".
[i.102] ETSI TS 103 410-10 (V1.1.1): "SmartM2M; Extension to SAREF; Part 10: Water Domain".
ETSI
11 ETSI TR 103 827 V1.1.1 (2023-09)
[i.103] Wang, Kai, et al. "A review of the technology standards for enabling digital twin". Digital
Twin 2.4 (2022): 4.
[i.104] ITU-T SG20: "Internet of things (IoT) and smart cities and communities (SC&C)".
[i.105] ISO/IEC 2382: "Information technology -- Vocabulary".
[i.106] ETSI TR 103 506: "SmartM2M; SAREF extension investigation; Requirements for Smart Cities".
[i.107] EN 13757-2: "Communication systems for meters - Part 2: Wired M-Bus communication"
(produced by CEN).
[i.108] TR 17167: "Communication system for meters. Accompanying TR to EN 13757-2,-3 and -7,
Examples and supplementary information" (produced by CEN).
[i.109] ETSI TS 103 828: "SmartM2M; SAREF: Ontology Support for Urban Digital Twins and usage
guidelines".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:
Digital Twin (DT): set of virtual information constructs that fully describes a potential or actual physical manufactured
product from the micro atomic level to the macro geometrical level
ontology: formal specification of a conceptualization, used to explicit capture the semantics of a certain reality
real time: timespan sufficient for the entity to accomplish the task for which the entity has been built
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AI Artificial Intelligence
API Application Programming Interface
BIM Building Information Modelling
DT Digital Twin
IoT Internet of Things
JSON JavaScript Object Notation
OWL Web Ontology Language
RDF Resource Description Framework
SAREF Smart Applications REFerence ontology
TR Technical Report
TS Technical Specification
XML Extensible Markup Language
ETSI
12 ETSI TR 103 827 V1.1.1 (2023-09)
4 Digital Twins Landscape for the Urban domain
In Europe, more than 74 % of the population resides in cities [i.1]. As urban populations grow, challenges arise, but so
do potential solutions [i.2]. With effective management, a city rich in human capital has the potential to become a hub
for exporting innovative solutions, often referred to as an 'innovation machine' [i.3]. Such a scenario is desirable as
innovations bring economic benefits and enhance citizens' quality of life [i.4]. However, it is not straightforward for city
management to assemble such a machine. Instead, what they truly seek is an ecosystem. By organizing all stakeholders,
including private companies and public entities, in a well-coordinated manner, there is a promise of improved economic
efficiency [i.5]. Due to the complexity involved, centrally managing the system stifles its dynamics. Hence, the solution
lies in an ecosystem that incentivizes participants to align themselves appropriately. This ecosystem leverages the core
strengths of each player to foster innovation, operates dynamically, and can be guided through a process called
orchestration [i.6]. Orchestration entails harmoniously organizing activities through effective planning, enabling
informed decision-making, and avoiding costly impromptu problem-solving. Digitalization aids in activity planning by
ensuring essential information is readily available and facilitates stakeholder involvement, ensuring everyone is
informed with the latest updates. This is why DTs hold value for cities.
DTs were first established in manufacturing [i.7] and [i.8]. Then, they have been used in several other domains like
construction [i.9] and [i.10], facilities management [i.11] and [i.12], industrial maintenance [i.13], and smart city
applications [i.14], [i.15] and [i.16]. Depending on the domain in which a DT is used, different types of interaction with
the physical world is implemented. Figure 4-1 shows a summary of the main types of interaction between DTs and the
physical world.
A holistic city DT differs from previous ones by accommodating various levels of detail specific to different local areas.
Given the presence of buildings from different time periods within a city, it becomes necessary to scan and integrate
them into the DT. These scanning efforts, along with updates, typically occur incidentally during other activities,
resulting in internal variations in the level of detail across different areas and themes. When a construction or
maintenance project takes place in a city district, that specific area is meticulously scanned, leading to a locally detailed
update. The remaining parts of the city DT remain unaffected and retain their previous level of detail. However, a city
DT should adhere to the original concept of digital planning for a collectively shared model, similar to its application in
manufacturing. To effectively serve ecosystem orchestration, a city DT has to also consider human factors. It entails not
only the characteristics of a computer model but also the organization of everyday services within the city to facilitate
collaborative planning in a shared digital model. Striking a balance between technocracy and democracy is crucial to
genuinely involve stakeholders. Consequently, if any changes are made to an existing city, digital planning should
address the resulting consequences on the dynamics of the city. Moreover, this digital planning should be accessible to
third parties for testing new services and alterations to city plans.

Figure 4-1: Summary of the main types of interactions between DTs and the physical world
Certain DT techniques provide advantages to city management, as observed in Helsinki [i.17], Zurich [i.18], and Vienna
[i.19]. Although these DTs fall under the same DT umbrella [i.20], they possess distinct characteristics and cater to
different purposes. One can argue that they represent evolving DTs that lie between maintenance-focused DTs and
comprehensive city DTs, effectively addressing a wide range of urban requirements.
ETSI
13 ETSI TR 103 827 V1.1.1 (2023-09)
Therefore, it is conceivable to inquire about the usefulness of DTs in addressing the needs of cities. What should be
included in a DT of a city and how should it be regularly updated (as shown in Figure 4-1) to serve a dynamic
ecosystem and improve its efficiency? It can be argued that a DT of a city would represent the ultimate achievement in
digitizing city assets and services, consisting of the following four components:
1) The foundation of the DT should be designed to meet the city's specific requirements.
2) The DT should support a wide range of content with varying levels of detail, including well-developed
Building Information Modelling (BIM) information, as well as less detailed content that accounts for local
variations.
3) Keeping the DT up to date is crucial due to the continuous changes that occur in a city. This involves
automated updates from sensor systems, such as Internet of Things (IoT) sensor networks, drones, and robotic
cars, as well as data collected through professional surveying.
4) To ensure the benefits of interacting with DTs, it is essential to have secure and user-friendly systems that
enable agents to visualize and share information effectively, enhancing decision-making processes.
Considering human factors is crucial in identifying the potential advantages and future applications of
DT systems in supporting city decision making.
5 Digital Twins and Ontologies
5.1 Introduction
Previous studies on DT models, as described by Grieves [i.21], consisted of three main components:
i) a physical environment encompassing real-world physical entities;
ii) a virtual environment consisting of digital objects and computational tools; and
iii) a connection for data and information exchange between the physical and virtual environments.
Grieves and Vickers [i.22] further classified DTs into three sub-types:
i) a DT prototype that includes requirements and models related to the concept of a physical entity;
ii) a DT instance that represents a specific physical entity throughout its entire lifecycle; and
iii) the DT environment, which is an integrated, multi-domain physics application space where DTs operate and
abide by the laws of physics and relevant rules.
Another more advanced model suggests five dimensions for DTs [i.23]:
i) a physical environment;
ii) a virtual environment that encompasses all models representing physical entities;
iii) services executed by the DTs, such as model execution, visualization, machine learning prediction, task
allocation, and maintenance;
iv) data accessible to the DT from both the physical and virtual environments; and
v) connections linking all the dimensions together.
ETSI
14 ETSI TR 103 827 V1.1.1 (2023-09)
In contrast to the three-dimensional model, the 5D model distinguishes between data and communications, and
additionally incorporates services within the DT domain, typically provided externally to the virtual environment where
the DT's settings and properties are defined, such as on a cloud platform.
The creation of a DT involves a computational process that consists of various computational services representing
models for each stage of the process and their interactions. As a result, DT platforms need to effectively coordinate
these independent services to offer both flexibility and computational efficiency. To achieve this, a DT platform should
encompass different levels of abstraction, as follows [i.24]:
• DT User Level: At this level, users can access the available DTs through applications designed for this
purpose.
• DT Developer Level: This level of the platform provides resources and tools for developers to create and
customize DTs.
• Computational Service Developer Level: The platform also offers an API (Application Programming
Interface) for developers to build computational services that can be integrated into the DT ecosystem.
• Infrastructure Provider Level: Here, the platform facilitates the allocation of computing resources by mapping
instances of the computational services to the appropriate computing infrastructure.
The initial step in establishing a DT's ontology involves delving into the concept of a model. Since a DT's virtual
environment consists of representations of the physical environment, it is important to define what a model entails.
Referring to a model as an artifact that abstracts a system or process from a specific perspective [i.25], it is possible to
identify several distinct aspects:
i) the idea of modelling itself, which is considered a universal concept of modelling;
ii) a model as a representation that includes information, rules, methods, and premises, such as a 3D model or a
class model;
iii) a model of a particular type, serving as a prototype, like a 3D model of a car; and
iv) an individual model, such as a 3D model of John's car.
It is worth noting that a model universal refers to a type whose instances are models since each model embodies a
specific modelling concept (e.g. 3D Model, 2D Model). General model universals can be specialized subtypes of model
universals, representing prototypes that individual models have to adhere to in terms of properties, dispositions, and
modes. The same entity can be represented by models instantiating different prototypes, which are specific subtypes of
model universals.
Therefore, it is essential to have a comprehensive theory with multiple levels [i.26] to define how a model fits into a DT
ontology. This theory should cover various aspects such as power-types and categorization schemes, which are integral
parts of the subject matter [i.27]. According to Guizzardi et al. [i.27], a prototype can be seen as a power-type that has
variable embodiments, which classify instances of individual models. A variable embodiment is an individual entity
that, in each scenario, adopts a specific fixed embodiment - a group of individuals related to each other - based on a
given principle. Consequently, a prototype can possess overarching properties that describe that particular variable
embodiment, including properties derived from instances of models associated with an individual classified by the
prototype. It can also have regularity properties that capture patterns observed across instances of a specific type, as
well as direct properties of the type itself, but not of any individual instance [i.27].
DTs are commonly associated with objects like cars, spacecraft, or oil platforms, as well as agents like people,
companies, or societies. While it is possible to model events and moments, the focus of DTs is typically on these objects
and agents. In the real world, an event occurs and involves the object or agent of interest. This event needs to be
mapped to a corresponding event in the digital world that reflects the real situation and involves the model. Similarly, a
moment that exists within an object or
...