{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T09:26:19Z","timestamp":1772529979479,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2018,8,29]],"date-time":"2018-08-29T00:00:00Z","timestamp":1535500800000},"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 Power Wide Area Networks (LPWANs) are gaining attention in both academia and industry by offering the possibility of connecting a large number of nodes over extended distances. LoRa is one of the technologies used as a physical layer in such networks. This paper investigates the LoRa links over seawater in two typical scenarios: clear Line-of-Sight (LOS) and obstructed path in two different Industrial, Scientific and Medical (ISM) radio bands:     868     MHz and     434     MHz. We used three different LoRa devices in the experiments: the Own Developed LoRa Transceiver (ODT) and two commercial transceivers. Firstly we investigated transceivers\u2019 Receive Signal Strength Indicator (RSSI) and Signal-to-Noise (SNR) measurement chain linearity and provided correction factors for RSSI to correlate it with actual signal levels received at transceivers\u2019 inputs. Next, we carried out field experiments for three different LoRa Spreading Factors,     S F \u2208 [  7 , 10 , 12  ]    , within a bandwidth of     B W = 125     kHz and Coding Rate     C R = 4 \/ 6    . The experiments showed that LoRa links are fully feasible over seawater at distances at least     22     km long, using only low-cost off-the-shelf rubber duck antennas in LOS path condition in both ISM bands. In addition, we showed that LoRa links can be established over     28     km obstructed LOS oversea path in ISM     434     MHz band, but using costly, higher gain antennas. Furthermore, the laboratory experiments revealed that RSSI is linear in a wide range, up to     \u2212 50     dBm, whereas the SNR measurement chain goes into saturation for Received Signal Strength (RSS) values higher than     \u2212 100     dBm. These findings enabled accurate interpretation of the results obtained in field experiments.<\/jats:p>","DOI":"10.3390\/s18092853","type":"journal-article","created":{"date-parts":[[2018,8,30]],"date-time":"2018-08-30T02:49:34Z","timestamp":1535597374000},"page":"2853","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":52,"title":["Experimental Study of LoRa Transmission over Seawater"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3707-687X","authenticated-orcid":false,"given":"Nikola","family":"Jovalekic","sequence":"first","affiliation":[{"name":"Department of Electronics, School of Electrical Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11060 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6437-5408","authenticated-orcid":false,"given":"Vujo","family":"Drndarevic","sequence":"additional","affiliation":[{"name":"Department of Electronics, School of Electrical Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11060 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7083-5319","authenticated-orcid":false,"given":"Ermanno","family":"Pietrosemoli","sequence":"additional","affiliation":[{"name":"Telecommunications\/ICT4D Lab, ICTP, Str. Costiera 11, 34151 Trieste, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2091-2616","authenticated-orcid":false,"given":"Iain","family":"Darby","sequence":"additional","affiliation":[{"name":"IAEA Nuclear Science and Instrumentation Laboratory, IAEA Laboratories Seibersdorf A-2444, 2444 Seibersdorf, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0578-0830","authenticated-orcid":false,"given":"Marco","family":"Zennaro","sequence":"additional","affiliation":[{"name":"Telecommunications\/ICT4D Lab, ICTP, Str. Costiera 11, 34151 Trieste, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,8,29]]},"reference":[{"key":"ref_1","unstructured":"Iridium (2018, June 30). Iridium Maritime Solutions. Available online: https:\/\/www.iridium.com\/solutions\/maritime\/."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Kazdaridis, G., Symeonidis, P., Zographopoulos, I., Korakis, T., Klun, K., and Kovac, N. (2017, January 18\u201320). On the development of energy-efficient communications for marine monitoring deployments. Proceedings of the 2017 13th International Conference on Advanced Technologies, Systems and Services in Telecommunications (TELSIKS), Nis, Serbia.","DOI":"10.1109\/TELSKS.2017.8246278"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Boydstun, D., Farich, M., McCarthy, J., Rubinson, S., Smith, Z., and Rekleitis, I. (2015, January 3\u20135). Drifter sensor network for environmental monitoring. Proceedings of the 2015 12th Conference on Computer and Robot Vision, Halifax, NS, Canada.","DOI":"10.1109\/CRV.2015.10"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Pozzebon, A., Cappelli, I., Mecocci, A., Bertoni, D., Sarti, G., and Alquini, F. (2018). A wireless sensor network for the real-time remote measurement of aeolian sand transport on sandy beaches and dunes. Sensors, 18.","DOI":"10.3390\/s18030820"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Trasvi\u00f1a-Moreno, C., Blasco, R., Marco, \u00c1., Casas, R., and Trasvi\u00f1a-Castro, A. (2017). Unmanned aerial vehicle based wireless sensor network for marine-coastal environment monitoring. Sensors, 17.","DOI":"10.3390\/s17030460"},{"key":"ref_6","unstructured":"Semtech (2018, June 30). LoRa Modulation Basics. Available online: https:\/\/www.semtech.com\/uploads\/documents\/an1200.22.pdf."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Petajajarvi, J., Mikhaylov, K., Roivainen, A., Hanninen, T., and Pettissalo, M. (2015, January 2\u20134). On the coverage of lpwans: Range evaluation and channel attenuation model for lora technology. Proceedings of the 2015 14th International Conference on ITS Telecommunications (ITST), Copenhagen, Denmark.","DOI":"10.1109\/ITST.2015.7377400"},{"key":"ref_8","unstructured":"ETSI (2018, June 30). EN 300 220-1 V3.1.0 (2016-05). Available online: http:\/\/www.etsi.org\/deliver\/etsi_en\/300200_300299\/30022001\/03.01.00_20\/en_30022001v030100a.pdf."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Li, L., Ren, J., and Zhu, Q. (2017, January 21\u201324). On the application of lora lpwan technology in sailing monitoring system. Proceedings of the 2017 13th Annual Conference on Wireless On-demand Network Systems and Services (WONS), Jackson, WY, USA.","DOI":"10.1109\/WONS.2017.7888762"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Jovalekic, N., Drndarevic, V., Darby, I., Zennaro, M., Pietrosemoli, E., and Ricciato, F. (2018). LoRa transceiver with improved characteristics. IEEE Wirel. Commun. Lett.","DOI":"10.1109\/LWC.2018.2855744"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1818","DOI":"10.1109\/LSP.2017.2762960","article-title":"Frequency shift chirp modulation: The lora modulation","volume":"24","author":"Vangelista","year":"2017","journal-title":"IEEE Signal Process. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Reynders, B., and Pollin, S. (2016, January 22). Chirp spread spectrum as a modulation technique for long range communication. Proceedings of the 2016 Symposium on Communications and Vehicular Technologies (SCVT), Mons, Belgium.","DOI":"10.1109\/SCVT.2016.7797659"},{"key":"ref_13","unstructured":"(2018, June 30). Spread SpectrumScene. The Advantages of Constant Envelope Modulation. Available online: http:\/\/sss-mag.com\/cem.html."},{"key":"ref_14","unstructured":"Bastille Networks (2018, June 30). Decoding LoRa, a Wireless Network for the Internet of Things. Available online: https:\/\/www.rsaconference.com\/writable\/presentations\/file_upload\/hta-f01-decoding-lora-a-wireless-network-for-the-internet-of-things_copy1.pdf."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Petajajarvi, J., Mikhaylov, K., Pettissalo, M., Janhunen, J., and Iinatti, J. (2017). Performance of a low-power wide-area network based on LoRa technology: Doppler robustness, scalability, and coverage. Int. J. Distrib. Sens. Netw., 3.","DOI":"10.1177\/1550147717699412"},{"key":"ref_16","unstructured":"Libelium (2018, June 30). Sx1272 LoRa Module for Arduino, Raspberry Pi and Intel Galileo\u2014868 MHz [xbee socket]. Available online: https:\/\/www.cooking-hacks.com\/documentation\/tutorials\/extreme-range-lora-sx1272-module-shield-arduino-raspberry-pi-intel-galileo."},{"key":"ref_17","unstructured":"Uputronics (2018, June 30). Raspberry Pi+ LoRa Expansion Board. Available online: https:\/\/store.uputronics.com\/index.php?route=product\/product&product_id=68."},{"key":"ref_18","unstructured":"Semtech (2018, June 30). Sx1276\/77\/78\/79\u2014137 MHz to 1020 MHz Low Power Long Range Transceiver. Available online: https:\/\/www.semtech.com\/uploads\/documents\/DS_SX1276-7-8-9_W_APP_V5.pdf."},{"key":"ref_19","unstructured":"Semtech (2018, June 30). Errata Note: Sx1276\/77\/78\u2014137 to 1020 MHz Low Power Long Range Transceiver. Available online: https:\/\/www.semtech.com\/uploads\/documents\/sx1276_77_78-errata.pdf."},{"key":"ref_20","unstructured":"Silicon Labs (2018, June 30). EFM32GG990 Datasheet. Available online: https:\/\/www.silabs.com\/documents\/public\/data-sheets\/EFM32GG990.pdf."},{"key":"ref_21","unstructured":"Micron Technology Inc. (2018, June 30). Nand128-a Nand256-a Datasheet. Available online: https:\/\/www.micron.com\/~\/media\/documents\/products\/data-sheet\/...\/nandxxx-a.pdf."},{"key":"ref_22","unstructured":"Semtech (2018, June 30). Sx1272\/73\u2014860 MHz to 1020 MHz Low Power Long Range Transceiver. Available online: https:\/\/www.semtech.com\/uploads\/documents\/sx1272.pdf."},{"key":"ref_23","unstructured":"Seeed Inc. (2018, June 30). Seeeduino Stalker v2.3. Available online: http:\/\/wiki.seeedstudio.com\/Seeeduino_Stalker_v2.3\/."},{"key":"ref_24","unstructured":"HopeRF (2018, June 30). RFM95\/96\/97\/98(w)\u2014Low Power Long Range Transceiver Module. Available online: http:\/\/www.hoperf.com\/upload\/rf\/RFM95_96_97_98W.pdf."},{"key":"ref_25","unstructured":"Raspberry Pi Foundation (2018, June 30). Raspberry Pi3 Specifications. Available online: https:\/\/www.raspberrypi.org\/products\/raspberry-pi-3-model-b\/."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Zennaro, M., Rainone, M., and Pietrosemoli, E. (2017). Radio link planning made easy with a telegram bot. Smart Objects and Technologies for Social Good, Springer International Publishing.","DOI":"10.1007\/978-3-319-61949-1_31"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Gaelens, J., Van Torre, P., Verhaevert, J., and Rogier, H. (2017). Lora mobile-to-base-station channel characterization in the antarctic. Sensors, 17.","DOI":"10.3390\/s17081903"},{"key":"ref_28","unstructured":"Youssef, N., Wang, C.X., Patzold, M., Jaafar, I., and Tabbane, S. (2004, January 17\u201319). On the statistical properties of generalized Rice multipath fading channels. Proceedings of the 2004 IEEE 59th Vehicular Technology Conference. VTC 2004-Spring, Milan, Italy."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Boano, C., Cattani, M., and R\u00f6mer, K. (2018, January 22\u201324). Impact of Temperature Variations on the Reliability of LoRa\u2014An Experimental Evaluation. Proceedings of the 7th International Conference on Sensor Networks\u2014Volume 1 (SENSORNETS), Madeira, Portugal.","DOI":"10.5220\/0006605600390050"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Boano, C.A., Brown, J., He, Z., Roedig, U., and Voigt, T. (2009, January 24\u201325). Low-power radio communication in industrial outdoor deployments: The impact of weather conditions and ATEX-compliance. Proceedings of the 1st International Conference on Sensor Networks Applications, Experimentation and Logistics (SENSAPPEAL), Athens, Greece.","DOI":"10.1007\/978-3-642-11870-8_11"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/9\/2853\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:21:57Z","timestamp":1760196117000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/9\/2853"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,8,29]]},"references-count":30,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2018,9]]}},"alternative-id":["s18092853"],"URL":"https:\/\/doi.org\/10.3390\/s18092853","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,8,29]]}}}