As broadband Internet speeds continue to increase, the home wireless ("WiFi") network may more frequently become a performance bottleneck. Past research, now nearly a decade old, initially documented this phenomenon through indirect inference techniques, noting the prevalence of WiFi bottlenecks but never directly measuring them. In the intervening years, access network (and WiFi) speeds have increased, warranting a re-appraisal of this important question, particularly with renewed private and federal investment in access network infrastructure. This paper studies this question, developing a new system and measurement technique to perform direct measurements of WiFi and access network performance, ultimately collecting and analyzing a first-of-its-kind dataset of more than 13,000 joint measurements of WiFi and access network throughputs, in a real-world deployment spanning more than 50 homes, for nearly two years. Using this dataset, we re-examine the question of whether, when, and to what extent a user's home wireless network may be a performance bottleneck, particularly relative to their access connection. We do so by directly and continuously measuring the user's Internet performance along two separate components of the Internet path -- from a wireless client inside the home network to the wired point of access (e.g., the cable modem), and from the wired point of access to the user's ISP. Confirming and revising results from more than a decade ago, we find that a user's home wireless network is often the throughput bottleneck. In particular, for users with access links that exceed 800~Mbps, the user's home wireless network was the performance bottleneck 100% of the time.

翻译：随着宽带互联网速度持续提升，家庭无线局域网（WiFi）可能更频繁地成为性能瓶颈。十年前的研究曾通过间接推断技术初步记录了这一现象，指出WiFi瓶颈的普遍性，但从未进行直接测量。在此期间，接入网络（及WiFi）速度显著提升，亟需重新评估这一关键问题——尤其当私有和联邦资金再次大力投入接入网络基础设施建设之际。本文针对该问题展开研究，开发了一套新型系统和测量技术，实现对WiFi与接入网络性能的直接测量，最终在覆盖50余户家庭的真实部署环境中，历时近两年收集并分析了包含超过13,000组WiFi与接入网络吞吐量联合测量的首创数据集。基于该数据集，我们重新审视了用户家庭无线网络是否、何时以及在多大程度上可能成为性能瓶颈（特别是相较于其接入链路），通过持续直接测量互联网路径中两个独立组件的性能——从家庭网络内部无线客户端到有线接入点（如线缆调制解调器），再由有线接入点至用户互联网服务提供商（ISP）。研究结果印证并修正了十余年前的结论：用户家庭无线网络常构成吞吐量瓶颈。具体而言，当用户接入链路速率超过800Mbps时，其家庭无线网络在100%的场景下均为性能瓶颈。