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，家庭无线网络（"WiFi"）可能更频繁地成为性能瓶颈。十年前的研究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直接测量。在随后的十年间，接入网络（及WiFi）速度不断提升，尤其是在私营和联邦政府对接入网络基础设施的新一轮投资背景下，有必要重新评估这一重要问题。本文通过开发新型系统与测量技术，对WiFi和接入网络性能开展直接测量，最终在横跨50余个家庭、持续近两年的真实部署环境中，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个此类数据集。基于该数据集，我们重新审视了用户家庭无线网络何时、在何种程度上会成为性能瓶颈（尤其是相对于其接入连接而言）的问题。具体方法是通过直接且持续地测量用户互联网路径中两个独立组件的性能——从家庭网络内部的无线客户端到有线接入点（如有线调制解调器），以及从有线接入点至用户ISP。我们确认并修正了十多年前的研究结论，发现用户家庭无线网络通常为吞吐量瓶颈。特别地，对于接入链路速率超过800 Mbps的用户，其家庭无线网络在100%的情况下都是性能瓶颈。