{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T18:50:04Z","timestamp":1772304604707,"version":"3.50.1"},"reference-count":57,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,6,25]],"date-time":"2025-06-25T00:00:00Z","timestamp":1750809600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000780","name":"European Commission","doi-asserted-by":"publisher","award":["101092968 (COGNIFOG)"],"award-info":[{"award-number":["101092968 (COGNIFOG)"]}],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Future Internet"],"abstract":"<jats:p>This paper explores the broad area of Smart City services and how the evolving Cloud-Edge-IoT continuum can support application deployment in Smart Cities. We initially introduce a range of Smart City services and highlight their computational needs. We then discuss the role of the Cloud-Edge-IoT continuum as a technological platform to meet those needs. To validate this approach, we present the COGNIFOG platform, a Cloud-Edge-IoT platform developed to support city-centric use cases, and an initial technology trial that shows the early benefits of using the platform. We conclude with plans for improvements to COGNIFOG based on the trials and with a broader set of observations on the future of the Cloud-Edge-IoT continuum in Smart City services and applications.<\/jats:p>","DOI":"10.3390\/fi17070281","type":"journal-article","created":{"date-parts":[[2025,6,25]],"date-time":"2025-06-25T08:23:22Z","timestamp":1750839802000},"page":"281","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["The Internet of Things, Fog, and Cloud Continuum: Integration Challenges and Opportunities for Smart Cities"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2442-7693","authenticated-orcid":false,"given":"Rodger","family":"Lea","sequence":"first","affiliation":[{"name":"School of Computing and Communication, Lancaster University, Lancaster LA1 4YW, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9789-9777","authenticated-orcid":false,"given":"Toni","family":"Adame","sequence":"additional","affiliation":[{"name":"Fundaci\u00f3 i2CAT, Gran Capit\u00e0 2-4, 08034 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0620-4317","authenticated-orcid":false,"given":"Alexandre","family":"Berne","sequence":"additional","affiliation":[{"name":"Commissariat \u00e0 l\u2019\u00c9nergie Atomique et aux \u00c9nergies Alternatives, Laboratoire d\u2019Int\u00e9gration de Syst\u00e8mes et des Technologies (CEA LIST), Universit\u00e9 Paris-Saclay, F-91120 Palaiseau, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9630-6738","authenticated-orcid":false,"given":"Selma","family":"Azaiez","sequence":"additional","affiliation":[{"name":"Commissariat \u00e0 l\u2019\u00c9nergie Atomique et aux \u00c9nergies Alternatives, Rue Leblanc 25, F-75015 Paris, France"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1080\/10630732.2014.942092","article-title":"Smart Cities: Definitions, Dimensions, Performance, and Initiatives","volume":"22","author":"Albino","year":"2015","journal-title":"J. Urban Technol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Ammara, U., Rasheed, K., Mansoor, A., Al-Fuqaha, A., and Qadir, J. (2022). Smart Cities from the Perspective of Systems. Systems, 10.","DOI":"10.3390\/systems10030077"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Adame, T., Amri, E., Antonopoulos, G., Azaiez, S., Berne, A., Camargo, J.S., Kakoulidis, H., Kleisarchaki, S., Llamedo, A., and Prasinos, M. (2024). Presenting the COGNIFOG Framework: Architecture, Building Blocks and Road toward Cognitive Connectivity. Sensors, 24.","DOI":"10.3390\/s24165283"},{"key":"ref_4","unstructured":"Lea, R. (2017). Smart Cities: An Overview of the Technology Trends Driving Smart Cities. IEEE Technol. Trend Pap., Available online: http:\/\/www.ieee.org\/content\/dam\/ieee-org\/ieee\/web\/org\/about\/corporate\/ieee-industry-advisory-board\/ieee-smart-cities-trend-paper-2017.pdf."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"392","DOI":"10.1177\/0020852314564308","article-title":"Governing the smart city: A review of the literature on smart urban governance","volume":"82","author":"Meijer","year":"2016","journal-title":"Int. Rev. Adm. Sci."},{"key":"ref_6","first-page":"143","article-title":"Smart governance in the context of smart cities: A literature review","volume":"23","author":"Pereira","year":"2018","journal-title":"Inf. Polity"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"I1","DOI":"10.1016\/j.giq.2014.09.001","article-title":"Being smart: Emerging technologies and innovation in the public sector","volume":"31","author":"Helbig","year":"2014","journal-title":"Gov. Inf. Q."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1108\/SJME-03-2022-0035","article-title":"Internet of Things (IoT) in smart tourism: A literature review","volume":"26","author":"Novera","year":"2022","journal-title":"Span. J. Mark. ESIC"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Phillipson, F., Eichler, G., Erfurth, C., and Fahrnberger, G. (2022). The Role of a Data Marketplace for Innovation and Value-Added Services in Smart and Sustainable Cities. Innovations for Community Services, Springer International Publishing.","DOI":"10.1007\/978-3-031-06668-9"},{"key":"ref_10","first-page":"102648","article-title":"The future energy internet for utility energy service and demand-side management in smart grid: Current practices, challenges and future directions","volume":"53","author":"Parvin","year":"2022","journal-title":"Sustain. Energy Technol. Assess."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Musa, A.A., Malami, S.I., Alanazi, F., Ounaies, W., Alshammari, M., and Haruna, S.I. (2023). Sustainable Traffic Management for Smart Cities Using Internet-of-Things-Oriented Intelligent Transportation Systems (ITS): Challenges and Recommendations. Sustainability, 15.","DOI":"10.3390\/su15139859"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Mavlutova, I., Atstaja, D., Grasis, J., Kuzmina, J., Uvarova, I., and Roga, D. (2023). Urban Transportation Concept and Sustainable Urban Mobility in Smart Cities: A Review. Energies, 16.","DOI":"10.3390\/en16083585"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"17471","DOI":"10.1109\/ACCESS.2023.3241588","article-title":"A Review on Digital Twin Technology in Smart Grid, Transportation System and Smart City: Challenges and Future","volume":"11","author":"Jafari","year":"2023","journal-title":"IEEE Access"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1057\/s41599-022-01145-0","article-title":"The \u201815-Minute City\u2019 concept can shape a net-zero urban future","volume":"9","author":"Allam","year":"2022","journal-title":"Humanit. Soc. Sci. Commun."},{"key":"ref_15","unstructured":"(2025, February 24). IoT-Enabled Smart Waste Management Systems for Smart Cities: A Systematic Review. Available online: https:\/\/ieeexplore.ieee.org\/abstract\/document\/9815071."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"100972","DOI":"10.1016\/j.uclim.2021.100972","article-title":"Review of urban computing in air quality management as smart city service: An integrated IoT, AI, and cloud technology perspective","volume":"39","author":"Kaginalkar","year":"2021","journal-title":"Urban Clim."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"122380","DOI":"10.1016\/j.eswa.2023.122380","article-title":"Experts and intelligent systems for smart homes\u2019 Transformation to Sustainable Smart Cities: A comprehensive review","volume":"238","author":"Huda","year":"2023","journal-title":"Expert Syst. Appl."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Sharifi, A., Khavarian-Garmsir, A.R., and Kummitha, R.K.R. (2021). Contributions of Smart City Solutions and Technologies to Resilience against the COVID-19 Pandemic: A Literature Review. Sustainability, 13.","DOI":"10.3390\/su13148018"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Militano, L., Arteaga, A., Toffetti, G., and Mitton, N. (2023). The Cloud-to-Edge-to-IoT Continuum as an Enabler for Search and Rescue Operations. Futur. Internet, 15.","DOI":"10.3390\/fi15020055"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/j.procs.2022.07.015","article-title":"Internet of Behaviour (IoB)-based AI models for personalized smart education systems","volume":"203","author":"Embarak","year":"2022","journal-title":"Procedia Comput. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Shin, S.-Y., Kim, D., and Chun, S.A. (2021). Digital Divide in Advanced Smart City Innovations. Sustainability, 13.","DOI":"10.3390\/su13074076"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Lea, R., Blackstock, M., Giang, N., and Vogt, D. (2015). Smart Cities: Engaging Users and Developers to Foster Innovation Ecosystems. UbiComp\/ISWC\u201915 Adjunct, Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing and Proceedings of the 2015 ACM International Symposium on Wearable Computers, Osaka, Japan, 9\u201311 September 2015, ACM.","DOI":"10.1145\/2800835.2801629"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.iot.2018.09.005","article-title":"The Internet of Things, Fog and Cloud continuum: Integration and challenges","volume":"3\u20134","author":"Bittencourt","year":"2018","journal-title":"Internet Things"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Gkonis, P., Giannopoulos, A., Trakadas, P., Masip-Bruin, X., and D\u2019andria, F. (2023). A Survey on IoT-Edge-Cloud Continuum Systems: Status, Challenges, Use Cases, and Open Issues. Futur. Internet, 15.","DOI":"10.20944\/preprints202311.0532.v1"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"101840","DOI":"10.1016\/j.is.2021.101840","article-title":"The convergence and interplay of edge, fog, and cloud in the AI-driven Internet of Things (IoT)","volume":"107","author":"Firouzi","year":"2022","journal-title":"Inf. Syst."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"101272","DOI":"10.1016\/j.iot.2024.101272","article-title":"The computing continuum: From IoT to the cloud","volume":"27","author":"Jansen","year":"2024","journal-title":"Internet Things"},{"key":"ref_27","unstructured":"(2025, June 02). Home. EUCloudEdgeIOT. Available online: https:\/\/eucloudedgeiot.eu\/."},{"key":"ref_28","unstructured":"(2025, June 02). Home. HE-CODECO. Available online: https:\/\/he-codeco.eu\/."},{"key":"ref_29","unstructured":"(2025, June 02). Myrtus|Multi-Layer 360\u00b0 dYnamic Orchestration and Interoperable Design Environment for Compute-Continuum Systems. Available online: https:\/\/myrtus-project.eu\/."},{"key":"ref_30","unstructured":"(2025, June 02). Swarmchestrate|Horizon Europe Co-Funded Project in Cognitive Computing Continuum. Available online: https:\/\/www.swarmchestrate.eu\/."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s13677-023-00516-5","article-title":"Orchestration in the Cloud-to-Things compute continuum: Taxonomy, survey and future directions","volume":"12","author":"Ullah","year":"2023","journal-title":"J. Cloud Comput."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Giang, N.K., Lea, R., Blackstock, M., and Leung, V.C. (2018, January 2\u20137). Fog at the Edge: Experiences Building an Edge Computing Platform. Proceedings of the 2018 IEEE International Conference on Edge Computing (EDGE), San Francisco, CA, USA.","DOI":"10.1109\/EDGE.2018.00009"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"10200","DOI":"10.1109\/JIOT.2020.2987070","article-title":"Edge-Computing-Enabled Smart Cities: A Comprehensive Survey","volume":"7","author":"Khan","year":"2020","journal-title":"IEEE Internet Things J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"38864","DOI":"10.1109\/ACCESS.2023.3267471","article-title":"Edge-Cloud Continuum Solutions for Urban Mobility Prediction and Planning","volume":"11","author":"Belcastro","year":"2023","journal-title":"IEEE Access"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Colarusso, C., Falco, I., and Zimeo, E. (2024, January 19\u201321). Towards business continuity with Edge-Cloud continuum. Proceedings of the 2024 11th International Conference on Future Internet of Things and Cloud (FiCloud), Vienna, Austria.","DOI":"10.1109\/FiCloud62933.2024.00046"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"12792","DOI":"10.1109\/JIOT.2020.3014845","article-title":"Cloud-Edge Orchestration for the Internet of Things: Architecture and AI-Powered Data Processing","volume":"8","author":"Wu","year":"2020","journal-title":"IEEE Internet Things J."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Hamdan, S., Ayyash, M., and Almajali, S. (2020). Edge-Computing Architectures for Internet of Things Applications: A Survey. Sensors, 20.","DOI":"10.3390\/s20226441"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1109\/MNET.2018.1700101","article-title":"Selective Offloading in Mobile Edge Computing for the Green Internet of Things","volume":"32","author":"Lyu","year":"2018","journal-title":"IEEE Netw."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"103887","DOI":"10.1016\/j.scs.2022.103887","article-title":"Edge-cloud resource federation for sustainable cities","volume":"82","author":"Ahmed","year":"2022","journal-title":"Sustain. Cities Soc."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Giang, N.K., Lea, R., Blackstock, M., and Leung, V.C.M. (2016). On Building Smart City IoT Applications: A Coordination-based Perspective. SmartCities\u201916, Proceedings of the 2nd International Workshop on Smart, London, UK, 12\u201313 September 2016, ACM.","DOI":"10.1145\/3009912.3009919"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/3510415","article-title":"Machine Learning-based Orchestration of Containers: A Taxonomy and Future Directions","volume":"54","author":"Zhong","year":"2022","journal-title":"ACM Comput. Surv."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"100390","DOI":"10.1016\/j.cosrev.2021.100390","article-title":"Energy, performance and cost efficient cloud datacentres: A survey","volume":"40","author":"Khan","year":"2021","journal-title":"Comput. Sci. Rev."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1016\/j.comcom.2020.01.004","article-title":"Energy aware edge computing: A survey","volume":"151","author":"Jiang","year":"2020","journal-title":"Comput. Commun."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.jpdc.2022.04.004","article-title":"Distributed intelligence on the Edge-to-Cloud Continuum: A systematic literature review","volume":"166","author":"Rosendo","year":"2022","journal-title":"J. Parallel Distrib. Comput."},{"key":"ref_45","unstructured":"Mhiri, S., and Paulus, Y. (2025, June 19). Cognifog-Threat-Model.pdf. COGNIFOG Project. Available online: https:\/\/cognifog.eu\/wp-content\/uploads\/2024\/05\/Threat-Model.pdf."},{"key":"ref_46","unstructured":"Louise, S. (2019). A Data Flow Model with Frequency Arithmetic. Lect. Notes Comput. Sci., Available online: https:\/\/www.academia.edu\/110493394\/A_Data_Flow_Model_with_Frequency_Arithmetic."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Petrakis, K., Agorogiannis, E., Antonopoulos, G., Anagnostopoulos, T., Grigoropoulos, N., Veroni, E., Berne, A., Azaiez, S., Benomar, Z., and Kakoulidis, H. (2025). Enhancing DevOps Practices in the IoT\u2013Edge\u2013Cloud Continuum: Architecture, Integration, and Software Orchestration Demonstrated in the COGNIFOG Framework. Software, 4.","DOI":"10.3390\/software4020010"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"79978","DOI":"10.1109\/ACCESS.2024.3406861","article-title":"A Framework for Cognitive, Decentralized Container Orchestration","volume":"12","author":"Sofia","year":"2024","journal-title":"IEEE Access"},{"key":"ref_49","unstructured":"(2025, June 19). ARCA Trusted OS. CYSEC. Available online: https:\/\/www.cysec.com\/arca-trusted-os\/."},{"key":"ref_50","unstructured":"(2025, June 19). Eclipse Project. Available online: https:\/\/projects.eclipse.org\/projects\/technology.sensinact."},{"key":"ref_51","unstructured":"Kentyou (2025, June 19). Kentyou Eye. Available online: https:\/\/kentyou.com\/kentyou-eye\/."},{"key":"ref_52","unstructured":"(2025, June 19). COGNIFOG Project. Public Deliverables\u2014COGNIFOG. Available online: https:\/\/cognifog.eu\/public-deliverables\/."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1109\/COMST.2022.3218527","article-title":"Distributed Artificial Intelligence Empowered by End-Edge-Cloud Computing: A Survey","volume":"25","author":"Duan","year":"2023","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1016\/j.future.2024.02.024","article-title":"Expanding the cloud-to-edge continuum to the IoT in serverless federated learning","volume":"155","author":"Loconte","year":"2024","journal-title":"Futur. Gener. Comput. Syst."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1062","DOI":"10.1016\/j.future.2019.07.047","article-title":"A survey on quality-assurance approximate stream processing and applications","volume":"101","author":"Wei","year":"2019","journal-title":"Futur. Gener. Comput. Syst."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"4095","DOI":"10.1007\/s10586-024-04383-w","article-title":"Modeling the Green Cloud Continuum: Integrating energy considerations into Cloud\u2013Edge models","volume":"27","author":"Patel","year":"2024","journal-title":"Clust. Comput."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"476","DOI":"10.3390\/smartcities4020025","article-title":"Energy Harvesting Mechanisms in a Smart City\u2014A Review","volume":"4","author":"Carvalho","year":"2021","journal-title":"Smart Cities"}],"container-title":["Future Internet"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1999-5903\/17\/7\/281\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:58:23Z","timestamp":1760032703000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1999-5903\/17\/7\/281"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,25]]},"references-count":57,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2025,7]]}},"alternative-id":["fi17070281"],"URL":"https:\/\/doi.org\/10.3390\/fi17070281","relation":{},"ISSN":["1999-5903"],"issn-type":[{"value":"1999-5903","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,25]]}}}