{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T09:47:19Z","timestamp":1785836839404,"version":"3.56.0"},"reference-count":17,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T00:00:00Z","timestamp":1785801600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Low Earth Orbit (LEO) Non-Terrestrial Networks (NTNs) are emerging as a promising connectivity solution for Internet of Things (IoT) sensing applications deployed in remote, isolated, or infrastructure-limited environments. However, sparse LEO constellations inherently lead to intermittent connectivity, long service gaps, and frequent disruptions, challenging conventional 5G architectures that assume continuous end-to-end availability. This paper presents and experimentally validates a distributed 5G Core architecture enhanced with Store-and-Forward (S&amp;F) capabilities to enable reliable delivery of IoT sensing data over intermittently connected LEO-NTN scenarios. The proposed architecture distributes selected 5G Core functions between ground and satellite nodes and introduces an S&amp;F module capable of locally buffering uplink IoT data during periods without feeder-link connectivity and forwarding them once the ground connection is restored. A functional prototype is implemented using Open5GS, UERANSIM, and an emulated satellite node, and experimentally evaluated under representative intermittent-connectivity conditions. The results demonstrate that the proposed architecture successfully preserves and delivers IoT sensing data across temporary link disruptions. The experimental findings confirm the feasibility of integrating S&amp;F mechanisms into distributed 5G Core architectures and provide practical insights into the design of resilient IoT sensing services over sparse LEO constellations.<\/jats:p>","DOI":"10.3390\/s26154919","type":"journal-article","created":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T09:15:22Z","timestamp":1785834922000},"page":"4919","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Experimental Validation of a Distributed 5G Core with Store-and-Forward for IoT Sensing over LEO Non-Terrestrial Networks"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0035-3944","authenticated-orcid":false,"given":"Victor Monzon","family":"Baeza","sequence":"first","affiliation":[{"name":"Faculty of Computer Science, Multimedia and Telecommunications, Universitat Oberta de Catalunya, Rambla del Poblenou 156, 08018 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-9560-2810","authenticated-orcid":false,"given":"Francesc Xavier","family":"Romero Soto","sequence":"additional","affiliation":[{"name":"Faculty of Computer Science, Multimedia and Telecommunications, Universitat Oberta de Catalunya, Rambla del Poblenou 156, 08018 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1899-5881","authenticated-orcid":false,"given":"Ra\u00fal","family":"Parada","sequence":"additional","affiliation":[{"name":"Centre Tecnol\u00f2gic de Telecomunicacions de Catalunya, Av. Carl Friedrich Gauss, 7-Edifici B4, 08860 Castelldefels, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3883-3588","authenticated-orcid":false,"given":"Carlos","family":"Monzo","sequence":"additional","affiliation":[{"name":"Faculty of Computer Science, Multimedia and Telecommunications, Universitat Oberta de Catalunya, Rambla del Poblenou 156, 08018 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,4]]},"reference":[{"key":"ref_1","unstructured":"3GPP (2026, July 29). Solutions for NR to Support Non-Terrestrial Networks (NTN); Technical Report TR 38.821, 3rd Generation Partnership Project; Version 16.1.0, Release 16. Available online: https:\/\/www.3gpp.org\/DynaReport\/38821.htm."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Hanifah, S., Kurnianingrum, I.P., Jamil, A.R.A., Yovita, L.V., and Wibowo, T.A. (2025, January 24\u201327). 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(2021). Nonclassical Attack on a Quantum Key Distribution System. Entropy, 23.","DOI":"10.3390\/e23050509"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/15\/4919\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T09:20:02Z","timestamp":1785835202000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/26\/15\/4919"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,4]]},"references-count":17,"journal-issue":{"issue":"15","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["s26154919"],"URL":"https:\/\/doi.org\/10.3390\/s26154919","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,4]]}}}