论文标题
基于测量的Google/Apple曝光通知API评估通勤总线中的接近性检测
Measurement-Based Evaluation Of Google/Apple Exposure Notification API For Proximity Detection in a Commuter Bus
论文作者
论文摘要
我们报告了使用Google/Apple曝光通知（GAEN）API在爱尔兰都柏林的通勤总线上进行的一项测量研究结果。该API可能会被COVID-19触点跟踪应用程序广泛使用。在60对手机位置之间收集了测量，并可以公开使用。我们发现，Gaen API报告的衰减水平不必随着手机之间的距离而增加，这与由金属富含金属富的环境引起的公共汽车内部有一个复杂的无线电环境。改变拿着一双手机的人，否则手机的位置保持不变，可能会在Gaen API报告的衰减水平中导致+/- 10dB的变化。应用瑞士联合-19触点跟踪应用程序使用的规则触发通知到我们的总线测量结果，我们发现，尽管所有手机对彼此至少在15分钟内彼此2m之内，但仍不会触发任何曝光通知。当使用15分钟的曝光持续时间阈值时，应用替代阈值的曝光通知规则可以在某种程度上提高性能为5％的检测率，当暴露持续时间阈值降低到10分钟时，增加到8％。根据手机对之间的距离对数据进行分层，这表明检测率对距离的依赖性较弱。
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 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 holding a pair of handsets, with the location of the handsets otherwise remaining unchanged, can cause variations of +/-10dB 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.
