{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,9]],"date-time":"2026-02-09T02:00:58Z","timestamp":1770602458286,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2020,1,31]],"date-time":"2020-01-31T00:00:00Z","timestamp":1580428800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008736","name":"Fondo de Fomento al Desarrollo Cient\u00edfico y Tecnol\u00f3gico","doi-asserted-by":"publisher","award":["IT17M1001"],"award-info":[{"award-number":["IT17M1001"]}],"id":[{"id":"10.13039\/501100008736","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002941","name":"Departamento de Investigaciones Cient\u00edficas y Tecnol\u00f3gicas, Universidad de Santiago de Chile","doi-asserted-by":"publisher","award":["NA"],"award-info":[{"award-number":["NA"]}],"id":[{"id":"10.13039\/501100002941","id-type":"DOI","asserted-by":"publisher"}]},{"name":"STIC-AMSUD","award":["19-STIC-08"],"award-info":[{"award-number":["19-STIC-08"]}]},{"DOI":"10.13039\/501100003593","name":"Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico","doi-asserted-by":"publisher","award":["NA"],"award-info":[{"award-number":["NA"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>In this manuscript we propose a hybrid Visible Light Communication and Radio Frequency (VLC-RF) scheme for the implementation of a portable Phaser Measurement Unit (PMU) for deep underground tunnels. Through computer simulations and laboratory measurements we are capable of providing Coordinated Universal Time (UTC) to the PMUs, as well as high accuracy positioning in a Global Positioning System (GPS) denied environment. The estimated PMU position, time stamp, and electrical power system measurements are sent to a central monitoring station using a radio frequency uplink with a data rate of hundreds of Kbps. Simulations and experimental measurements show that the proposed scheme can be used to control a large number of VLC-RF PMU devices inside a tunnel. The tests demonstrate the viability of the hybrid prototype, which will improve performance compared to commercial PMUs that lack these features.<\/jats:p>","DOI":"10.3390\/s20030790","type":"journal-article","created":{"date-parts":[[2020,1,31]],"date-time":"2020-01-31T11:55:56Z","timestamp":1580471756000},"page":"790","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["A Hybrid VLC-RF Portable Phasor Measurement Unit for Deep Tunnels"],"prefix":"10.3390","volume":"20","author":[{"given":"Ismael","family":"Soto","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, Universidad de Santiago de Chile, Santiago 9170124, Chile"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rafael","family":"Nilson Rodrigues","sequence":"additional","affiliation":[{"name":"Academic Department of Electrotechnic, Federal Institute of Santa Catarina, Florian\u00f3polis 88020-300, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabriel","family":"Massuyama","sequence":"additional","affiliation":[{"name":"Academic Department of Electrotechnic, Federal Institute of Santa Catarina, Florian\u00f3polis 88020-300, Brazil"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6567-8988","authenticated-orcid":false,"given":"Fabian","family":"Seguel","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Universidad de Santiago de Chile, Santiago 9170124, Chile"},{"name":"Universit\u00e9 de Lorraine, CRAN, CNRS UMR 7039, BP 70239 Nancy, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3958-503X","authenticated-orcid":false,"given":"Pablo","family":"Palacios J\u00e1tiva","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Universidad de Chile, Santiago 8370451, Chile"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3461-4484","authenticated-orcid":false,"given":"Cesar A.","family":"Azurdia-Meza","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Universidad de Chile, Santiago 8370451, Chile"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicolas","family":"Krommenacker","sequence":"additional","affiliation":[{"name":"Universit\u00e9 de Lorraine, CRAN, CNRS UMR 7039, BP 70239 Nancy, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,1,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Wache, M., and Murray, D.C. 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