{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,9]],"date-time":"2026-05-09T16:45:04Z","timestamp":1778345104523,"version":"3.51.4"},"reference-count":27,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2022,3,14]],"date-time":"2022-03-14T00:00:00Z","timestamp":1647216000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"technology and transfer (Tetra) of Flanders Innovation Entrepreneurship (Vlaio)","award":["HBC.2020.2073-Velcro"],"award-info":[{"award-number":["HBC.2020.2073-Velcro"]}]},{"name":"ICT-NETWORK collaboration program of the Council of Flemish Universities of Belgium (VLIR-UOS)","award":["CU2019NET033A105"],"award-info":[{"award-number":["CU2019NET033A105"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>It has been demonstrated that LoRa-based wide area networks (WANs) can cover extended areas under harsh propagation conditions. Traditional LoRaWAN solutions based on single-hop access face important drawbacks related to the presence of blind spots. This paper aims to tackle blind spots and performance issues by using a relaying approach. Many researchers investigating multi-hop solutions consider a fixed spreading factor (SF). This simplifies synchronization and association processes, but does not take advantage of the orthogonality between the virtual channels (i.e., frequency, SF) that help to mitigate blind spots. This paper proposes a time-slotted spreading factor hopping (TSSFH) mechanism that combines virtual channels and time slots into a frame structure. Pseudo-random scheduling is used inside blind spots, which simplifies the end-devices\u2019 communication process and network organization. The results show how collisions decrease inside blind spots when more communication opportunities become available as more relaying nodes can be listening in different cells (i.e., frequency, SF-offset, time-offset). This has a direct impact on the collision-free packet delivery ratio (PDR) metric, which improves when more listening windows are opened, at the expense of faster battery depletion.<\/jats:p>","DOI":"10.3390\/s22062253","type":"journal-article","created":{"date-parts":[[2022,3,15]],"date-time":"2022-03-15T02:56:20Z","timestamp":1647312980000},"page":"2253","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Time-Slotted Spreading Factor Hopping for Mitigating Blind Spots in LoRa-Based Networks"],"prefix":"10.3390","volume":"22","author":[{"given":"Alejandro","family":"Iglesias-Rivera","sequence":"first","affiliation":[{"name":"Departamento de Electr\u00f3nica y Telecomunicaciones, Universidad Central \u201cMarta Abreu\u201d de Las Villas, Santa Clara 50100, Villa Clara, Cuba"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8388-9375","authenticated-orcid":false,"given":"Roald","family":"Van Glabbeek","sequence":"additional","affiliation":[{"name":"Department of Engineering Technology (INDI), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium"},{"name":"Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2447-2892","authenticated-orcid":false,"given":"Erik Ortiz","family":"Guerra","sequence":"additional","affiliation":[{"name":"Departamento de Electr\u00f3nica y Telecomunicaciones, Universidad Central \u201cMarta Abreu\u201d de Las Villas, Santa Clara 50100, Villa Clara, Cuba"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9965-915X","authenticated-orcid":false,"given":"An","family":"Braeken","sequence":"additional","affiliation":[{"name":"Department of Engineering Technology (INDI), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kris","family":"Steenhaut","sequence":"additional","affiliation":[{"name":"Department of Engineering Technology (INDI), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium"},{"name":"Department of Electronics and Informatics (ETRO), Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7927-3711","authenticated-orcid":false,"given":"Hector","family":"Cruz-Enriquez","sequence":"additional","affiliation":[{"name":"Departamento de Electr\u00f3nica y Telecomunicaciones, Universidad Central \u201cMarta Abreu\u201d de Las Villas, Santa Clara 50100, Villa Clara, Cuba"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,14]]},"reference":[{"key":"ref_1","unstructured":"Tehcnical Markworkgroup (2021, November 10). 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