More and more consumer devices implement the IEEE Ultra-Wide Band (UWB) standard to perform distance measurements for sensitive tasks such as keyless entry and startup of modern cars, to find lost items using coin-sized trackers, and for smart payments. While UWB promises the ability to perform time-of-flight centimeter-accurate distance measurements between two devices, the accuracy and reliability of the implementation in up-to-date consumer devices have not been evaluated so far. In this paper, we present the first evaluation of UWB smartphones from Apple, Google, and Samsung, focusing on accuracy and reliability in passive keyless entry and smart home automation scenarios. To perform the measurements for our analysis, we build a custom-designed testbed based on a Gimbal-based platform for Wireless Evaluation (GWEn), which allows us to create reproducible measurements. All our results, including all measurement data and a manual to reconstruct a GWEn are published online. We find that the evaluated devices can measure the distance with an error of less than 20cm, but fail in producing reliable measurements in all scenarios. Finally, we give recommendations on how to handle measurement results when implementing a passive keyless entry system.

翻译：越来越多的消费设备采用IEEE超宽带（UWB）标准，用于执行敏感任务中的距离测量，例如现代汽车的无钥匙进入与启动、利用硬币大小的追踪器寻找丢失物品以及智能支付。尽管UWB声称能够在两台设备之间实现厘米级精度的飞行时间距离测量，但迄今为止，尚缺乏对当前消费设备中该实现方案的准确性与可靠性的评估。本文首次对苹果、谷歌和三星的UWB智能手机进行了评估，重点关注其在无钥匙进入和智能家居自动化场景中的准确性与可靠性。为进行测量分析，我们基于用于无线评估的云台平台（GWEn）构建了定制化的测试平台，从而实现可重复的测量。我们的所有结果（包括全部测量数据及重建GWEn的操作手册）均已在线公开。研究发现，被评估设备能够以低于20厘米的误差测量距离，但在所有场景中均未能生成可靠的测量结果。最后，我们就实施无钥匙进入系统时如何处理测量结果给出了建议。