{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T16:58:54Z","timestamp":1774630734451,"version":"3.50.1"},"reference-count":57,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,4,29]],"date-time":"2021-04-29T00:00:00Z","timestamp":1619654400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010661","name":"Horizon 2020 Framework Programme","doi-asserted-by":"publisher","award":["780139"],"award-info":[{"award-number":["780139"]}],"id":[{"id":"10.13039\/100010661","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The short latency required by IoT devices that need to access specific services have led to the development of Fog architectures that can serve as a useful intermediary between IoT systems and the Cloud. However, the massive numbers of IoT devices that are being deployed raise concerns about the power consumption of such systems as the number of IoT devices and Fog servers increase. Thus, in this paper, we describe a software-defined network (SDN)-based control scheme for client\u2013server interaction that constantly measures ongoing client\u2013server response times and estimates network power consumption, in order to select connection paths that minimize a composite goal function, including both QoS and power consumption. The approach using reinforcement learning with neural networks has been implemented in a test-bed and is detailed in this paper. Experiments are presented that show the effectiveness of our proposed system in the presence of a time-varying workload of client-to-service requests, resulting in a reduction of power consumption of approximately 15% for an average response time increase of under 2%.<\/jats:p>","DOI":"10.3390\/s21093105","type":"journal-article","created":{"date-parts":[[2021,4,29]],"date-time":"2021-04-29T10:30:41Z","timestamp":1619692241000},"page":"3105","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Smart SDN Management of Fog Services to Optimize QoS and Energy"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4854-4256","authenticated-orcid":false,"given":"Piotr","family":"Fr\u00f6hlich","sequence":"first","affiliation":[{"name":"Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, 44-100 Gliwice, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9688-2201","authenticated-orcid":false,"given":"Erol","family":"Gelenbe","sequence":"additional","affiliation":[{"name":"Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, 44-100 Gliwice, Poland"},{"name":"Laboratoire I3S, Universit\u00e9 C\u00f4te d\u2019Azur, 06103 Nice, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0551-6746","authenticated-orcid":false,"given":"Jerzy","family":"Fio\u0142ka","sequence":"additional","affiliation":[{"name":"Faculty of Automatic Control, Electronics and Computer Science, The Silesian University of Technology, Akademicka 2A, 44-100 Gliwice, Poland"}]},{"given":"Jacek","family":"Ch\u0119ci\u0144ski","sequence":"additional","affiliation":[{"name":"Faculty of Automatic Control, Electronics and Computer Science, The Silesian University of Technology, Akademicka 2A, 44-100 Gliwice, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8331-9599","authenticated-orcid":false,"given":"Mateusz","family":"Nowak","sequence":"additional","affiliation":[{"name":"Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, 44-100 Gliwice, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2494-6856","authenticated-orcid":false,"given":"Zdzis\u0142aw","family":"Filus","sequence":"additional","affiliation":[{"name":"Faculty of Automatic Control, Electronics and Computer Science, The Silesian University of Technology, Akademicka 2A, 44-100 Gliwice, Poland"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"105:1","DOI":"10.1145\/3241737","article-title":"A Manifesto for Future Generation Cloud Computing: Research Directions for the Next Decade","volume":"51","author":"Buyya","year":"2019","journal-title":"ACM Comput. 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