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Creators/Authors contains: "Peng, Chunyi"

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  1. Free, publicly-accessible full text available June 19, 2025
  2. In this work, we present our attempt to tackle the last-hundred-feet problem for autonomous drone delivery.We take a computer-vision based approach to progressively landing towards a convenient and safe drop-off point at all times (here, at the front/garage door). Specifically, we develop structural semantic segmentation (SSS), a new technique that leverages a single-family house structure to streamline and enhance semantic segmentation in the drop-to-door problem context.We implement SSS into an Android app; Our preliminary evaluation in a residential zone shows SSS is promising to make autonomous drop-to-door in real-time, with no need to wait for slow visual processing. Video demo is available at Youtube [5]. App is released at Github [6]. 
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    Free, publicly-accessible full text available February 28, 2025
  3. In this work, we have conducted a measurement study with three US operators to reveal three types of problematic failure handling on secondary radio access which have not been reported before. Compared to primary radio access failures, secondary radio access failures do not hurt radio access availability but significantly impact data performance, particularly when 5G is used as secondary radio access to boost throughput. Improper failure handling results in significant throughput loss, which is unnecessary in most instances. Datasets are available at https:// github.com/mssn/ scgfailure. 
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    Free, publicly-accessible full text available February 28, 2025
  4. Free, publicly-accessible full text available May 29, 2025
  5. Carrier aggregation (CA) is an important component technology in 5G and beyond. It aggregates multiple spectrum fragments to serve a mobile device. However, the current CA suffers under both high mobility and increased spectrum space. The limitations are rooted in its sequential, cell-by-cell operations. In this work, we propose CA++, which departs from the current paradigm and explores a group-based design scheme. We thus propose new algorithms that enable concurrent channel inference by measuring one or few cells but inferring all, while minimizing measurement cost via set cover approximations. Our evaluations have confirmed the effectiveness of CA++. Our solution can also be adapted to fit in the current 5G OFDM PHY and the 3GPP framework. 
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  6. In this paper, we study an important, yet unexplored problem of configuration dependencies in 5G/4.5G radio resource control (RRC). Different from the previous studies in 3G/4G networks, 5G/4.5G allows more than one cells to serve a mobile device, resulting in more configuration dynamics and complexity that vary with all the serving cells. We analyze inter-dependency among configurations, categorize dependent misconfigurations, uncover their root causes, and quantify negative performance impacts. Specifically, we formulate configuration updates into a delta state machine (DSM) and unveil two types of dependent misconfigurations among states (inter-state) and within a state (intra-state); They stem from structural dependency and cross-parameter dependency. We further show that such misconfigurations incur service disruption and performance degradation. Our findings have been largely validated with three US operators and one Chinese operator; Our study has uncovered 644 instances of problematic dependencies.

     
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