{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T14:19:50Z","timestamp":1781705990065,"version":"3.54.5"},"reference-count":39,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2019,1,19]],"date-time":"2019-01-19T00:00:00Z","timestamp":1547856000000},"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>In this paper, a pervasive monitoring system to be deployed in underground environments is presented. The system has been specifically designed for the so-called \u201cBottini\u201d, i.e., the medieval aqueducts dug beneath the Centre of Siena, Italy. The results of a measurement campaign carried out in the deployment scenario show that the transmission range of LoRa (Long Range) technology is limited to a maximum of 200 m, thus, making the adoption of a classical star topology impossible. Hence, a Linear Sensor Network topology is proposed based on multi-hop LoRa chain-type communications. In this scenario, an ad-hoc transmission scheme is presented that optimally evaluates the wake-up time of all nodes with the aim of minimizing the average energy dissipation deriving from clock offsets. Numerical results show that the proposed wake-up time optimization leads in the best case to a 50% reduction in power dissipation with respect to a scheme that evaluates the wake-up time in a non-optimal way.<\/jats:p>","DOI":"10.3390\/s19020402","type":"journal-article","created":{"date-parts":[[2019,1,22]],"date-time":"2019-01-22T03:08:22Z","timestamp":1548126502000},"page":"402","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":95,"title":["A Multi-Hop LoRa Linear Sensor Network for the Monitoring of Underground Environments: The Case of the Medieval Aqueducts in Siena, Italy"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8006-0710","authenticated-orcid":false,"given":"Andrea","family":"Abrardo","sequence":"first","affiliation":[{"name":"Department of Information Engineering and Mathematical Sciences, University of Siena, 53100 Siena SI, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3991-8858","authenticated-orcid":false,"given":"Alessandro","family":"Pozzebon","sequence":"additional","affiliation":[{"name":"Department of Information Engineering and Mathematical Sciences, University of Siena, 53100 Siena SI, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,1,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"012104","DOI":"10.1088\/1742-6596\/476\/1\/012104","article-title":"Energy harvesting from fluid flow in water pipelines for smart metering applications","volume":"476","author":"Hoffmann","year":"2013","journal-title":"J. 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