{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T21:36:17Z","timestamp":1771018577335,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2019,2,18]],"date-time":"2019-02-18T00:00:00Z","timestamp":1550448000000},"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>LoRaWAN is one of the most promising standards for long-range sensing applications. However, the high number of end devices expected in at-scale deployment, combined with the absence of an effective synchronization scheme, challenge the scalability of this standard. In this paper, we present an approach to increase network throughput through a Slotted-ALOHA overlay on LoRaWAN networks. To increase the single channel capacity, we propose to regulate the communication of LoRaWAN networks using a Slotted-ALOHA variant on the top of the Pure-ALOHA approach used by the standard; thus, no modification in pre-existing libraries is necessary. Our method is based on an innovative synchronization service that is suitable for low-cost wireless sensor nodes. We modelled the LoRaWAN channel with extensive measurement on hardware platforms, and we quantified the impact of tuning parameters on physical and medium access control layers, as well as the packet collision rate. Results show that Slotted-ALOHA supported by our synchronization service significantly improves the performance of traditional LoRaWAN networks regarding packet loss rate and network throughput.<\/jats:p>","DOI":"10.3390\/s19040838","type":"journal-article","created":{"date-parts":[[2019,2,19]],"date-time":"2019-02-19T04:08:20Z","timestamp":1550549300000},"page":"838","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":169,"title":["Slotted ALOHA on LoRaWAN-Design, Analysis, and Deployment"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0405-3612","authenticated-orcid":false,"given":"Tommaso","family":"Polonelli","sequence":"first","affiliation":[{"name":"DEI, University of Bologna, 40123 Bologna, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5110-6823","authenticated-orcid":false,"given":"Davide","family":"Brunelli","sequence":"additional","affiliation":[{"name":"DII, University of Trento, I-38123 Trento, Italy"}]},{"given":"Achille","family":"Marzocchi","sequence":"additional","affiliation":[{"name":"DEI, University of Bologna, 40123 Bologna, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8068-3806","authenticated-orcid":false,"given":"Luca","family":"Benini","sequence":"additional","affiliation":[{"name":"DEI, University of Bologna, 40123 Bologna, Italy"},{"name":"IIS, ETH Zurich, 8092 Z\u00fcrich, Switzerland"}]}],"member":"1968","published-online":{"date-parts":[[2019,2,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1109\/COMST.2017.2652320","article-title":"Low power wide area networks: An overview","volume":"19","author":"Raza","year":"2017","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1645","DOI":"10.1016\/j.future.2013.01.010","article-title":"Internet of Things (IoT): A vision, architectural elements, and future directions","volume":"29","author":"Gubbi","year":"2013","journal-title":"Future Gen. Comput. Syst."},{"key":"ref_3","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_4","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1109\/MCOM.2017.1600613","article-title":"Understanding the limits of LoRaWAN","volume":"55","author":"Adelantado","year":"2017","journal-title":"IEEE Commun. Mag."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1466","DOI":"10.3390\/s16091466","article-title":"A study of LoRa: Long range & low power networks for the internet of things","volume":"16","author":"Augustin","year":"2016","journal-title":"Sensors"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Nolan, K.E., Guibene, W., and Kelly, M. (2016, January 5\u20139). An evaluation of low power wide area network technologies for the Internet of Things. Proceedings of the 2016 International Wireless Communications and Mobile Computing Conference (IWCMC), Paphos, Cyprus.","DOI":"10.1109\/IWCMC.2016.7577098"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Pet\u00e4j\u00e4j\u00e4rvi, 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., 13.","DOI":"10.1177\/1550147717699412"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1007\/s10776-017-0341-8","article-title":"Evaluation of LoRa LPWAN technology for indoor remote health and wellbeing monitoring","volume":"24","author":"Mikhaylov","year":"2017","journal-title":"Int. J. Wirel. Inf. Netw."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Neumann, P., Julien, M., and Thomas, N. (2016, January 17\u201319). Indoor deployment of low-power wide area networks (LPWAN): A LoRaWAN case study. Proceedings of the 2016 IEEE 12th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), New York, NY, USA.","DOI":"10.1109\/WiMOB.2016.7763213"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Magno, M., Aoudia, F.A., Gautier, M., Berder, O., and Benini, L. (2017, January 27\u201331). WULoRa: An energy efficient IoT end-node for energy harvesting and heterogeneous communication. Proceedings of the Conference on Design, Automation & Test in Europe, Lausanne, Switzerland.","DOI":"10.23919\/DATE.2017.7927233"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Sartori, D., and Brunelli, D. (2016, January 20). A smart sensor for precision agriculture powered by microbial fuel cells. Proceedings of the Sensors Applications Symposium (SAS), Catania, Italy.","DOI":"10.1109\/SAS.2016.7479815"},{"key":"ref_12","unstructured":"Sornin, N., Luis, M., Eirich, T., Kramp, T., and Hersent, O. (2015). Lorawan Specification, LoRa Alliance, Inc."},{"key":"ref_13","unstructured":"Alliance, L. (2019, January 19). LoRaWAN\u2122 Certified Products. Available online: https:\/\/www.lora-alliance.org\/Products\/Certified-Products."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Bor, M.C., Roedig, U., Voigt, T., and Alonso, J.M. (2016, January 21\u201325). Do LoRa low-power wide-area networks scale?. Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems, Miami, FL, USA.","DOI":"10.1145\/2988287.2989163"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Bankov, D., Khorov, E., and Lyakhov, A. (2016, January 29\u201330). On the limits of LoRaWAN channel access. Proceedings of the 2016 International Conference on Engineering and Telecommunication (EnT), Moscow, Russia.","DOI":"10.1109\/EnT.2016.011"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1109\/LWC.2016.2647247","article-title":"Low power wide area network analysis: Can LoRa scale?","volume":"6","author":"Georgiou","year":"2017","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1109\/MWC.2016.7721743","article-title":"Long-range communications in unlicensed bands: The rising stars in the IoT and smart city scenarios","volume":"23","author":"Centenaro","year":"2016","journal-title":"IEEE Wirel. Commun."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Yang, C., Liang, O., Ontanon, S., and Ke, W. (2018, January 18\u201320). Predictive Modeling with Vehicle Sensor Data and IoT for Injury Prevention. Proceedings of the 2018 IEEE 4th International Conference on Collaboration and Internet Computing (CIC), Philadelphia, PA, USA.","DOI":"10.1109\/CIC.2018.00047"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1671","DOI":"10.1016\/j.mejo.2014.05.019","article-title":"Clamp-and-Forget: A self-sustainable non-invasive wireless sensor node for smart metering applications","volume":"45","author":"Porcarelli","year":"2017","journal-title":"Microelectron. J."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Goursaud, C., and Gorce, J.-M. (2015). Dedicated networks for IoT: PHY \/ MAC state of the art and challenges. EAI Trans. Internet Things.","DOI":"10.4108\/eai.26-10-2015.150597"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Margelis, G., Piechocki, R., Kaleshi, D., and Thomas, P. (2015, January 14\u201316). Low throughput networks for the IoT: Lessons learned from industrial implementations. Proceedings of the 2015 IEEE 2nd World Forum on Internet of Things (WF-IoT), Milan, Italy.","DOI":"10.1109\/WF-IoT.2015.7389049"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Weyn, M., Ergeerts, G., Wante, L., Vercauteren, C., and Hellinckx, P. (2013). Survey of the DASH7 alliance protocol for 433 MHz wireless sensor communication. Int. J. Distrib. Sens. Netw.","DOI":"10.1155\/2013\/870430"},{"key":"ref_23","unstructured":"ISO-IEC (2014). ISO\/IEC 18000-7:2014 Information Technology \u201cRadio Frequency Identification for Item Managemen \u201cPart 7: \u201cParameters for Active Air Interface Communications at 433 MHz\u201d, ISO."},{"key":"ref_24","unstructured":"(2015). LoRaWAN\u2122, Specification v1.0, LoRa Alliance, Inc."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Polonelli, T., Brunelli, D., and Guermandi, M. (2018, January 4\u20137). An accurate low-cost Crackmeter with LoRaWAN communication and energy harvesting capability. Proceedings of the 2018 IEEE 23rd International Conference on Emerging Technologies and Factory Automation (ETFA), Turin, Italy.","DOI":"10.1109\/ETFA.2018.8502592"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2186","DOI":"10.1109\/JIOT.2017.2768498","article-title":"Scalability analysis of large-scale LoRaWAN networks in ns-3","volume":"4","author":"Haxhibeqiri","year":"2017","journal-title":"IEEE Internet Things J."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Polonelli, T., Brunelli, D., and Benini, L. (2018, January 29\u201331). Slotted ALOHA Overlay on LoRaWAN-A Distributed Synchronization Approach. Proceedings of the 2018 IEEE 16th International Conference on Embedded and Ubiquitous Computing (EUC), Bucharest, Romania.","DOI":"10.1109\/EUC.2018.00026"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Tessaro, L., Raffaldi, C., Rossi, M., and Brunelli, D. (2018, January 16\u201318). Lightweight Synchronization Algorithm with Self-Calibration for Industrial LORA Sensor Networks. Proceedings of the 2018 Workshop on Metrology for Industry 4.0 and IoT, Brescia, Italy.","DOI":"10.1109\/METROI4.2018.8428309"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Tessaro, L., Raffaldi, C., Rossi, M., and Brunelli, D. (2018, January 20\u201322). LoRa Performance in Short Range Industrial Applications. Proceedings of the 2018 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM), Amalfi, Italy.","DOI":"10.1109\/SPEEDAM.2018.8445392"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Rossi, M., Tosato, P., Gemma, L., Torquati, L., Catania, C., Camal\u00f2, S., and Brunelli, D. (2017, January 27\u201331). Long range wireless sensing powered by plant-microbial fuel cell. Proceedings of the 2017 Design, Automation & Test in Europe Conference & Exhibition (DATE), Lausanne, Switzerland.","DOI":"10.23919\/DATE.2017.7927258"},{"key":"ref_31","unstructured":"Bor, M., Vidler, J.E., and Roedig, U. (2016, January 15\u201317). Lora for the Internet of Things. Proceedings of the 2016 International Conference on Embedded Wireless Systems and Networks (EWSN \u201916), TU Graz, Austria."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Casals, L., Mir, B., Vidal, R., and Gomez, C. (2017). Modeling the energy performance of lorawan. Sensors, 17.","DOI":"10.3390\/s17102364"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Abramson, N. (1970, January 17\u201319). HE ALOHA SYSTEM: Another alternative for computer communications. Proceedings of the ACM Fall Joint Computer Conference, Houston, TX, USA.","DOI":"10.1145\/1478462.1478502"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1109\/25.406614","article-title":"Performance of an Exponential Backoff Scheme for Slotted-ALOHA Protocol in Local Wireless Environment","volume":"44","author":"Jeong","year":"1995","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_35","unstructured":"(2019, January 19). SX1276\/77\/78\/79 Transceivers. (01\/2019). Available online: https:\/\/www.semtech.com\/uploads\/documents\/DS_SX1276-7-8-9_W_APP_V5.pdf."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1400","DOI":"10.1109\/TCOM.1975.1092768","article-title":"Packet switching in radio channels: Part I\u2014Carrier sense multiple-access modes and their throughput-delay characteristics","volume":"23","author":"Kleinrock","year":"1975","journal-title":"IEEE Trans. Commun."},{"key":"ref_37","unstructured":"(2019, January 19). Conduit AEP: LoRa Communication and Node-RED. Hoboken, NJ, USA, 2019. Available online: http:\/\/www.multitech.net\/developer\/software\/lora\/conduit-aep-lora-communication\/."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1109\/JETCAS.2014.2337171","article-title":"Energy Neutral Wireless Sensing for Server Farms Monitoring","volume":"4","author":"Rossi","year":"2014","journal-title":"IEEE J. Emerg. Sel. Top. Circuits Syst."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/4\/838\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:32:55Z","timestamp":1760185975000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/4\/838"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,2,18]]},"references-count":38,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2019,2]]}},"alternative-id":["s19040838"],"URL":"https:\/\/doi.org\/10.3390\/s19040838","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,2,18]]}}}