{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T06:35:01Z","timestamp":1790836501644,"version":"4.1.0"},"reference-count":15,"publisher":"Public Library of Science (PLoS)","issue":"4","license":[{"start":{"date-parts":[[2021,4,29]],"date-time":"2021-04-29T00:00:00Z","timestamp":1619654400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001637","name":"Trinity College Dublin","doi-asserted-by":"publisher","award":["TACT"],"award-info":[{"award-number":["TACT"]}],"id":[{"id":"10.13039\/501100001637","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001602","name":"Science Foundation Ireland","doi-asserted-by":"crossref","award":["16\/IA\/4610"],"award-info":[{"award-number":["16\/IA\/4610"]}],"id":[{"id":"10.13039\/501100001602","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>We report on the results of a measurement study carried out on a commuter bus in Dublin, Ireland using the Google\/Apple Exposure Notification (GAEN) API. This API is likely to be widely used by Covid-19 contact tracing apps. Measurements were collected between 60 pairs of Android handset locations and are publicly available. We find that the attenuation level reported by the GAEN API need not increase with distance between handsets, consistent with there being a complex radio environment inside a bus caused by the metal-rich environment. Changing the people sitting in a pair of seats can cause variations of \u00b110dB in the attenuation level reported by the GAEN API. Applying the rule used by the Swiss Covid-19 contact tracing app to trigger an exposure notification to our bus measurements we find that no exposure notifications would have been triggered despite the fact that all pairs of handsets were within 2m of one another for at least 15 mins. Applying an alternative threshold-based exposure notification rule can somewhat improve performance to a detection rate of 5% when an exposure duration threshold of 15 minutes is used, increasing to 8% when the exposure duration threshold is reduced to 10 mins. Stratifying the data by distance between pairs of handsets indicates that there is only a weak dependence of detection rate on distance.<\/jats:p>","DOI":"10.1371\/journal.pone.0250826","type":"journal-article","created":{"date-parts":[[2021,4,29]],"date-time":"2021-04-29T17:56:26Z","timestamp":1619718986000},"page":"e0250826","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":20,"title":["Measurement-based evaluation of Google\/Apple Exposure Notification API for proximity detection in a commuter bus"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4056-4014","authenticated-orcid":true,"given":"Douglas J.","family":"Leith","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephen","family":"Farrell","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,4,29]]},"reference":[{"key":"pone.0250826.ref001","article-title":"Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing","author":"L Ferretti","year":"2020","journal-title":"Science"},{"key":"pone.0250826.ref002","unstructured":"Irish Times. EU urges vigilance to avoid coronavirus second wave; 17 May 2020. Available from: https:\/\/www.irishtimes.com\/news\/world\/europe\/eu-urges-vigilance-to-avoid-coronavirus-second-wave-1.4255632."},{"key":"pone.0250826.ref003","unstructured":"Apple and Google partner on COVID-19 contact tracing technology; 10 April, 2020. Available from: https:\/\/www.apple.com\/newsroom\/2020\/04\/apple-and-google-partner-on-covid-19-contact-tracing-technology\/."},{"key":"pone.0250826.ref004","unstructured":"Google Blog. Exposure Notification API launches to support public health agencies; Accessed 13 June 2020. Available from: https:\/\/blog.google\/inside-google\/company-announcements\/apple-google-exposure-notification-api-launches\/."},{"issue":"4","key":"pone.0250826.ref005","doi-asserted-by":"crossref","DOI":"10.1145\/3431832.3431840","article-title":"Coronavirus Contact Tracing: Evaluating The Potential Of Using Bluetooth Received Signal Strength For Proximity Detection","volume":"50","author":"DJ Leith","year":"2020","journal-title":"ACM Computer Communications Review"},{"key":"pone.0250826.ref006","author":"DJ Leith","year":"2020","journal-title":"Dublin Bus GAEN Attenuation Durations Dataset"},{"key":"pone.0250826.ref007","unstructured":"BBC News. Coronavirus: First Google\/Apple-based contact-tracing app launched; Accessed 14 June 2020. Available from: https:\/\/www.bbc.com\/news\/technology-52807635."},{"key":"pone.0250826.ref008","unstructured":"DP-3T Team. DP-3T Exposure Score Calculation Summary; Accessed 14 June 2020. Available from: https:\/\/github.com\/DP-3T\/documents\/blob\/master\/DP3T%20-%20Exposure%20Score%20Calculation.pdf."},{"key":"pone.0250826.ref009","doi-asserted-by":"crossref","unstructured":"Kita N, Ito T, Yokoyama S, Tseng M, Sagawa Y, Ogasawara M, et al. Experimental study of propagation characteristics for wireless communications in high-speed train cars. In: 2009 3rd European Conference on Antennas and Propagation; 2009. p. 897\u2013901.","DOI":"10.1109\/APS.2009.5172166"},{"issue":"8","key":"pone.0250826.ref010","doi-asserted-by":"crossref","first-page":"1060","DOI":"10.1049\/iet-map.2018.6132","article-title":"Experimental characterisation and modelling of intra-car communications inside highspeed trains","volume":"13","author":"L Zhang","year":"2019","journal-title":"IET Microwaves, Antennas and Propagation"},{"key":"pone.0250826.ref011","unstructured":"Exposure Notifications: Android API Documentation; accessed 6 June 2020. Available from: https:\/\/static.googleusercontent.com\/media\/www.google.com\/en\/\/covid19\/exposurenotifications\/pdfs\/Android-Exposure-Notification-API-documentation-v1.3.2.pdf."},{"key":"pone.0250826.ref012","author":"DJ Leith","year":"2020","journal-title":"GAEN Due Diligence: Verifying The Google\/Apple Covid Exposure Notification API"},{"key":"pone.0250826.ref013","volume":"9","author":"DJ Leith","year":"2020","journal-title":"Modified Exposure Notification App"},{"key":"pone.0250826.ref014","author":"S Farrell","year":"2020","journal-title":"A Coronavirus Contact Tracing App Replay Attack with Estimated Amplification Factors"},{"key":"pone.0250826.ref015","author":"M Briers","year":"2020","journal-title":"Risk scoring calculation for the current NHSx contact tracing app"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0250826","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,4,29]],"date-time":"2021-04-29T17:57:13Z","timestamp":1619719033000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0250826"}},"subtitle":[],"editor":[{"given":"Jacopo","family":"Soldani","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,4,29]]},"references-count":15,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2021,4,29]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0250826","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,4,29]]}}}