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PacketLab is a recently proposed model for accessing remote vantage points. The core design is for the vantage points to export low-level network operations that measurement researchers could rely on to construct more complex measurements. Motivating the model is the assumption that such an approach can overcome persistent challenges such as the operational cost and security concerns of vantage point sharing that researchers face in launching distributed active Internet measurement experiments. However, the limitations imposed by the core design merit a deeper analysis of the applicability of such model to real-world measurements of interest. We undertook this analysis based on a survey of recent Internet measurement studies, followed by an empirical comparison of PacketLab-based versus native implementations of common measurement methods. We showed that for several canonical measurement types common in past studies, PacketLab yielded similar results to native versions of the same measurements. Our results suggest that PacketLab could help reproduce or extend around 16.4% (28 out of 171) of all surveyed studies and accommodate a variety of measurements from latency, throughput, network path, to non-timing data. 

5G is a high-bandwidth low-latency communication technology that requires deploying new cellular base stations. The environmental cost of deploying a 5G cellular network remains unknown. In this work we answer several questions about the environmental impact of 5G deployment, including: Can we reuse minerals from discarded 4G base stations to build 5G or does 5G require new minerals that were not required in 4G base stations? And, how sustainable is this transition? We answered these questions buy surveying the minerals needed to build 5G base stations. We found that the key technologies behind 5G require additional rare-earth metals to build essential semiconductor components needed for 5G, such as yttrium, barium, gallium, and germanium. Additionally, since 5G needs many more base stations than 4G network to achieve the same coverage, we describe how 5G will likely increase the use of materials like copper, gold, and aluminum, all of which are difficult or impractical to recycle from the 4G base stations they will replace. We estimate that to provide coverage comparable to 4G in the United States, we will need about 600 million 5G base stations, which will consume thousands of tons of these metals and significant amount of fossil fuels, as well as will result in releasing toxic gases during material mining and refining. Despite these environment costs, we also describe the environmental benefits that a 5G network can offer. 

Using a toolbox of Internet cartography methods, and new ways of applying them, we have undertaken a comprehensive active measurement-driven study of the topology of U.S. regional access ISPs. We used state-of-the-art approaches in various combinations to accommodate the geographic scope, scale, and architectural richness of U.S. regional access ISPs. In addition to vantage points from research platforms, we used public WiFi hotspots and public transit of mobile devices to acquire the visibility needed to thoroughly map access networks across regions. We observed many different approaches to aggregation and redundancy, across links, nodes, buildings, and at different levels of the hierarchy. One result is substantial disparity in latency from some Edge COs to their backbone COs, with implications for end users of cloud services. Our methods and results can inform future analysis of critical infrastructure, including resilience to disasters, persistence of the digital divide, and challenges for the future of 5G and edge computing.