{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2024,9,12]],"date-time":"2024-09-12T13:12:32Z","timestamp":1726146752486},"reference-count":36,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2021,10,23]],"date-time":"2021-10-23T00:00:00Z","timestamp":1634947200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000780","name":"European Union","doi-asserted-by":"publisher","award":["871249"],"id":[{"id":"10.13039\/501100000780","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"High-precision indoor localisation is becoming a necessity with novel location-based services that are emerging around 5G. The deployment of high-precision indoor location technologies is usually costly due to the high density of reference points. In this work, we propose the opportunistic fusion of several different technologies, such as ultra-wide band (UWB) and WiFi fine-time measurement (FTM), in order to improve the performance of location. We also propose the use of fusion with cellular networks, such as LTE, to complement these technologies where the number of reference points is under-determined, increasing the availability of the location service. Maximum likelihood estimation (MLE) is presented to weight the different reference points to eliminate outliers, and several searching methods are presented and evaluated for the localisation algorithm. An experimental setup is used to validate the presented system, using UWB and WiFi FTM due to their incorporation in the latest flagship smartphones. It is shown that the use of multi-technology fusion in trilateration algorithm remarkably optimises the precise coverage area. In addition, it reduces the positioning error by over-determining the positioning problem. This technique reduces the costs of any network deployment oriented to location services, since a reduced number of reference points from each technology is required.<\/jats:p>","DOI":"10.3390\/s21217020","type":"journal-article","created":{"date-parts":[[2021,10,25]],"date-time":"2021-10-25T02:07:11Z","timestamp":1635127631000},"page":"7020","source":"Crossref","is-referenced-by-count":21,"title":["WiFi FTM, UWB and Cellular-Based Radio Fusion for Indoor Positioning"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"http:\/\/orcid.org\/0000-0001-7791-0369","authenticated-orcid":false,"given":"Carlos S.","family":"\u00c1lvarez-Merino","sequence":"first","affiliation":[{"name":"Instituto Universitario de Investigaci\u00f3n en Telecomunicaci\u00f3n (TELMA), University of M\u00e1laga, CEI Andalucia TECH E.T.S.I. Ingenier\u00eda de Telecommunication, Bulevar Louis Pasteur 35, 29010 M\u00e1laga, Spain"}]},{"ORCID":"http:\/\/orcid.org\/0000-0003-3024-0294","authenticated-orcid":false,"given":"Hao Qiang","family":"Luo-Chen","sequence":"additional","affiliation":[{"name":"Instituto Universitario de Investigaci\u00f3n en Telecomunicaci\u00f3n (TELMA), University of M\u00e1laga, CEI Andalucia TECH E.T.S.I. Ingenier\u00eda de Telecommunication, Bulevar Louis Pasteur 35, 29010 M\u00e1laga, Spain"}]},{"ORCID":"http:\/\/orcid.org\/0000-0001-8518-7297","authenticated-orcid":false,"given":"Emil Jatib","family":"Khatib","sequence":"additional","affiliation":[{"name":"Instituto Universitario de Investigaci\u00f3n en Telecomunicaci\u00f3n (TELMA), University of M\u00e1laga, CEI Andalucia TECH E.T.S.I. Ingenier\u00eda de Telecommunication, Bulevar Louis Pasteur 35, 29010 M\u00e1laga, Spain"}]},{"ORCID":"http:\/\/orcid.org\/0000-0002-8993-5229","authenticated-orcid":false,"given":"Raquel","family":"Barco","sequence":"additional","affiliation":[{"name":"Instituto Universitario de Investigaci\u00f3n en Telecomunicaci\u00f3n (TELMA), University of M\u00e1laga, CEI Andalucia TECH E.T.S.I. Ingenier\u00eda de Telecommunication, Bulevar Louis Pasteur 35, 29010 M\u00e1laga, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,23]]},"reference":[{"key":"ref_1","first-page":"1124","article-title":"Survey of cellular mobile radio localization methods: From 1G to 5G","volume":"20","author":"Raulefs","year":"2017","journal-title":"IEEE Commun. Surv. Tutor."},{"key":"ref_2","unstructured":"Mautz, R. (2021, August 29). Indoor Positioning Technologies. Permanent Link. Available online: https:\/\/www.research-collection.ethz.ch\/handle\/20.500.11850\/54888."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"6652","DOI":"10.1109\/ACCESS.2016.2606486","article-title":"A look at the recent wireless positioning techniques with a focus on algorithms for moving receivers","volume":"4","author":"Tahat","year":"2016","journal-title":"IEEE Access"},{"key":"ref_4","unstructured":"Decawave (2021, August 29). DWM1001 System Overview and Performance. Available online: https:\/\/www.decawave.com\/dwm1001\/systemoverview\/."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"101416","DOI":"10.1016\/j.pmcj.2021.101416","article-title":"Accurate indoor positioning using IEEE 802.11 mc round trip time","volume":"75","author":"Hashem","year":"2021","journal-title":"Pervasive Mob. Comput."},{"key":"ref_6","unstructured":"Yavari, M., and Nickerson, B.G. (2014). Ultra Wideband Wireless Positioning Systems, Department Fac. Computing Science, University of New Brunswick. Rep. TR14-230."},{"key":"ref_7","unstructured":"(ETSI), E.T.S.I (2021, September 02). Ultra Wide Band. Available online: https:\/\/www.etsi.org\/technologies\/ultra-wide-band?jjj=1596015945046."},{"key":"ref_8","unstructured":"(2021, April 29). LOCUS Project. Available online: https:\/\/www.locus-project.eu\/."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Keating, R., S\u00e4ily, M., Hulkkonen, J., and Karjalainen, J. (2019, January 27\u201330). Overview of positioning in 5G new radio. Proceedings of the 2019 16th International Symposium on Wireless Communication Systems (ISWCS), Oulu, Finland.","DOI":"10.1109\/ISWCS.2019.8877160"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2260","DOI":"10.1109\/LCOMM.2021.3074960","article-title":"Opportunistic fusion of ranges from different sources for indoor positioning","volume":"25","author":"Khatib","year":"2021","journal-title":"IEEE Commun. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1109\/MPRV.2016.69","article-title":"Chameleon: Survey-free updating of a fingerprint database for indoor localization","volume":"15","author":"He","year":"2016","journal-title":"IEEE Pervasive Comput."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Al-homayani, F., and Mahoor, M. (2018, January 24\u201327). Improved indoor geomagnetic field fingerprinting for smartwatch localization using deep learning. Proceedings of the 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN), Nantes, France.","DOI":"10.1109\/IPIN.2018.8626558"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Lobo, F.L., Lima, M., Oliveira, H., El-Khatib, K., and Harrington, J. (2017, January 21\u201325). Solve: A localization system framework for vanets using the cloud and fog computing. Proceedings of the 6th ACM Symposium on Development and Analysis of Intelligent Vehicular Networks and Applications, New York, NY, USA.","DOI":"10.1145\/3132340.3132350"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Verma, R.K., Pati, B., Panigrahi, C.R., Sarkar, J.L., and Mohapatra, S.D. (2018). M2C: An energy-efficient mechanism for computation in mobile cloud computing. Progress in Advanced Computing and Intelligent Engineering, Springer.","DOI":"10.1007\/978-981-10-6872-0_67"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Hou, X., and Arslan, T. (2017, January 27\u201329). Monte Carlo localization algorithm for indoor positioning using Bluetooth low energy devices. Proceedings of the 2017 International Conference on Localization and GNSS (ICL-GNSS). IEEE, Nottingham, UK.","DOI":"10.1109\/ICL-GNSS.2017.8376248"},{"key":"ref_16","unstructured":"Bluetooth (2021, July 10). 3 Key Factors That Determine the Range of Bluetooth. Available online: https:\/\/www.bluetooth.com\/learn-about-bluetooth\/key-attributes\/range\/#estimator."},{"key":"ref_17","unstructured":"Bartoletti, S., Conti, A., Dardari, D., and Giorgetti, A. (2018). 5G Localization and Context-Awareness, University of Ferrara."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"404","DOI":"10.1109\/JPROC.2008.2008846","article-title":"Ranging with ultrawide bandwidth signals in multipath environments","volume":"97","author":"Dardari","year":"2009","journal-title":"Proc. IEEE"},{"key":"ref_19","unstructured":"Daily, C. (2021, September 22). Apple AirTags Use UWB Wireless Tech. Here\u2019s How Ultra Wideband Makes Your Life Easier. Available online: https:\/\/www.cnet.com\/tech\/mobile\/apple-airtags-use-uwb-wireless-tech-heres-how-ultra-wideband-makes-your-life-easier\/."},{"key":"ref_20","unstructured":"I.C.S.L.S. Committee (2007). IEEE Standard for Information Technology-Telecommunications and Information Exchange between Systems-Local and Metropolitan Area Networks-Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, IEEE."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Gentner, C., Ulmschneider, M., Kuehner, I., and Dammann, A. (2020, January 20). WiFi-RTT Indoor Positioning. Proceedings of the 2020 IEEE\/ION Position, Location and Navigation Symposium (PLANS), Portland, OR, USA.","DOI":"10.1109\/PLANS46316.2020.9110232"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Martin-Escalona, I., and Zola, E. (2020). Passive round-trip-time positioning in dense IEEE 802.11 networks. Electronics, 9.","DOI":"10.3390\/electronics9081193"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Martin-Escalona, I., and Zola, E. (2020, January 7\u201311). Ranging Estimation Error in WiFi Devices Running IEEE 802.11 mc. Proceedings of the GLOBECOM 2020-2020 IEEE Global Communications Conference, Taipei, Taiwan.","DOI":"10.1109\/GLOBECOM42002.2020.9347973"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Teunissen, P., and Montenbruck, O. (2017). Springer Handbook of Global Navigation Satellite Systems, Springer.","DOI":"10.1007\/978-3-319-42928-1"},{"key":"ref_25","first-page":"155","article-title":"An introduction to maximum likelihood estimation and information geometry","volume":"17","author":"Miura","year":"2011","journal-title":"Interdiscip. Inf. Sci."},{"key":"ref_26","unstructured":"Zou, C. (2021, September 17). Lecture Notes on Asymptotic Statistics. Available online: http:\/\/web.stat.nankai.edu.cn\/chlzou\/Note_AS.pdf."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1007\/s10589-010-9329-3","article-title":"Implementing the Nelder-Mead simplex algorithm with adaptive parameters","volume":"51","author":"Gao","year":"2012","journal-title":"Comput. Optim. Appl."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1145\/279232.279236","article-title":"Algorithm 778: L-BFGS-B: Fortran subroutines for large-scale bound-constrained optimization","volume":"23","author":"Zhu","year":"1997","journal-title":"ACM Trans. Math. Softw. (TOMS)"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1894","DOI":"10.1016\/j.cageo.2011.03.017","article-title":"Application of MATLAB and Python optimizers to two case studies involving groundwater flow and contaminant transport modeling","volume":"37","author":"Matott","year":"2011","journal-title":"Comput. Geosci."},{"key":"ref_30","unstructured":"Koch, P., Bagheri, S., Foussette, C., Krause, P., B\u00e4ck, T., and Konen, W. (2014, January 27\u201328). Constrained optimization with a limited number of function evaluations. Proceedings of the ProcEEDings 24. Workshop comPutational intElligEncE, Dortmund, Germany."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2298\/SJEE2101001K","article-title":"End-effector Cartesian stiffness shaping-sequential least squares programming approach","volume":"18","year":"2021","journal-title":"Serbian J. Electr. Eng."},{"key":"ref_32","unstructured":"Community, S. (2020, April 30). Different Searching Methods for MLE. Available online: https:\/\/docs.scipy.org\/doc\/scipy\/reference\/generated\/scipy.optimize.minimize.html."},{"key":"ref_33","unstructured":"(2021, September 28). Google Support. Available online: https:\/\/support.google.com\/googlenest\/thread\/44036979\/google-wifi-transmit-power-value?hl=en."},{"key":"ref_34","unstructured":"(2021, September 28). DecaWave. Available online: https:\/\/www.decawave.com\/application-notes\/."},{"key":"ref_35","unstructured":"3GPP (2017). Study on channel model for frequencies from 0.5 to 100 GHz. Technical Report (TR) 38.901, 3rd Generation Partnership Project (3GPP), 3GPP."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"3643","DOI":"10.1109\/TWC.2020.2967726","article-title":"Machine learning-enabled LOS\/NLOS identification for MIMO systems in dynamic environments","volume":"19","author":"Huang","year":"2020","journal-title":"IEEE Trans. Wirel. Commun."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/21\/7020\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,7,20]],"date-time":"2024-07-20T16:56:13Z","timestamp":1721494573000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/21\/7020"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,10,23]]},"references-count":36,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["s21217020"],"URL":"https:\/\/doi.org\/10.3390\/s21217020","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,10,23]]}}}