{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T16:12:23Z","timestamp":1775578343490,"version":"3.50.1"},"reference-count":49,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,5,21]],"date-time":"2021-05-21T00:00:00Z","timestamp":1621555200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002560","name":"Soonchunhyang University","doi-asserted-by":"publisher","award":["The Soonchunhyang University Research Fund"],"award-info":[{"award-number":["The Soonchunhyang University Research Fund"]}],"id":[{"id":"10.13039\/501100002560","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper presents an in-depth overview of the Bluetooth 5.1 Direction Finding standard\u2019s potentials, thanks to enhancing the Bluetooth Low Energy (BLE) firmware. This improvement allows producers to create location applications based on the Angle of Departure (AoD) and the Angle of Arrival (AoA). Accordingly, it is conceivable to design proper Indoor Positioning Systems (IPS), for instance, for the traceability of resources, assets, and people. First of all, Radio Frequency (RF) radiogoniometry techniques, helpful in calculating AoA and AoD angles, are introduced in this paper. Subsequently, the topic relating to signal direction estimation is deepened. The Bluetooth Core Specification updates concerning version 5.1, both at the packet architecture and prototyping levels, are also reported. Some suitable platforms and development kits for running the new features are then presented, and some basic applications are illustrated. This paper\u2019s final part allows ascertaining the improvement made by this new definition of BLE and possible future developments, especially concerning applications related to devices, assets, or people\u2019s indoor localization. Some preliminary results gathered in a real evaluation scenario are also presented.<\/jats:p>","DOI":"10.3390\/s21113589","type":"journal-article","created":{"date-parts":[[2021,5,24]],"date-time":"2021-05-24T00:01:20Z","timestamp":1621814480000},"page":"3589","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":110,"title":["Bluetooth 5.1: An Analysis of Direction Finding Capability for High-Precision Location Services"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5798-398X","authenticated-orcid":false,"given":"Giovanni","family":"Pau","sequence":"first","affiliation":[{"name":"Faculty of Engineering and Architecture, Kore University of Enna, 94100 Enna, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6656-1797","authenticated-orcid":false,"given":"Fabio","family":"Arena","sequence":"additional","affiliation":[{"name":"Faculty of Engineering and Architecture, Kore University of Enna, 94100 Enna, Italy"}]},{"given":"Yonas Engida","family":"Gebremariam","sequence":"additional","affiliation":[{"name":"Department of ICT Environmental Health System, Graduate School, Soonchunhyang University, Asan 31538, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0604-3445","authenticated-orcid":false,"given":"Ilsun","family":"You","sequence":"additional","affiliation":[{"name":"Department of ICT Environmental Health System, Graduate School, Soonchunhyang University, Asan 31538, Korea"},{"name":"Department of Information Security Engineering, Soonchunhyang University, Asan 31538, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1138","DOI":"10.1016\/j.promfg.2020.10.160","article-title":"Comparative Study of Seamless Asset Location and Tracking Technologies","volume":"51","author":"Ahmed","year":"2020","journal-title":"Procedia Manuf."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1385","DOI":"10.1109\/TII.2019.2950109","article-title":"Smart Collaborative Automation for Receive Buffer Control in Multipath Industrial Networks","volume":"16","author":"Song","year":"2020","journal-title":"IEEE Trans. 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