arXiv subjects

Hardani Ismu Nabil

Publications and source records attributed to Hardani Ismu Nabil.

3 recordsLinked to original sources

arXiv2026

App-Based Performance Characterization of Cellular and Wi-Fi Networks in Dense Stadium Deployments

The concentration of 77,622 spectators during football games at Notre Dame Stadium creates an exceptionally demanding environment for wireless infrastructure. To handle this extreme user density, the stadium deploys concurrent multi-tier networks serving outdoor users: an enterprise 5/6 GHz Wi-Fi network with ~900 outdoor Access Points (APs) alongside high-density multi-carrier 4G/5G networks powered by a neutral-host small-cell Distributed Antenna System (DAS) with up to 129 unique cell identifiers (PCIs) per operator. This study evaluates user-perceived performance and QoE across these networks using commercial smartphones to execute web browsing, WhatsApp messaging, and Instagram media posting workloads. Our empirical results reveal that while cellular networks deliver strong peak downlink performance in an empty stadium, game-day crowd loads heavily strain uplink and latency performance, triggering a severe cellular "uplink gap." Under Non-Standalone (EN-DC) anchor congestion, web browsing handshakes suffer a catastrophic 5,983 ms P90 Time-to-First-Byte (TTFB), and image upload failure rates climb to 46%. Furthermore, while narrow low-band FDD channels (e.g., n5) maintain robust channel quality during uploads, they exhibit a 70% median Block Error Rate (BLER) during active browsing tests, driving a 36.6% page-load failure rate. Conversely, the dense stadium Wi-Fi infrastructure delivers downlink throughput comparable to the best performing 5G Standalone (SA) deployment while providing better uplink and latency resilience, yielding the lowest game-day page-load failure rate (3.9%) and bounding image upload latency degradation to just 2.1x relative to empty-stadium baselines. These insights proves that densification through localized Wi-Fi deployment is essential to absorb severe stadium traffic spikes.

cs.NI↗

arXiv2026

Comprehensive Analysis of Cellular Uplink Performance in a Dense Stadium Deployment

Uplink performance remains a critical limitation in modern 5G networks, where UEs have to balance limited transmission power against propagation challenges. We conducted extensive measurements in the University of Notre Dame's football stadium, which has a seating capacity of 80,000 spectators, evaluating network behavior under both unloaded (pregame) and severely congested (game day) conditions, with a focus on uplink performance. Analyzing PHY-layer metrics captured via the Rohde & Schwarz QualiPoc, we show that high-frequency TDD bands in the uplink are severely bottlenecked in both the spectral and temporal domains. Despite transmitting near maximum 3GPP power limits, propagation loss inherent to high-frequency bands restricts UEs to low MCS indices and low PRB allocations, even in unloaded networks. This inability to achieve wideband allocation is further compounded by the significantly smaller number of uplink slots compared to downlink slots in TDD frames. Consequently, we observe a severe disparity between uplink and downlink: while high-frequency TDD bands carry the majority of downlink throughput, the network relies heavily on lower-frequency FDD bands for uplink. Additional measurements under favorable propagation conditions around a Verizon COW deployment located in the stadium parking lot also show that this limitation is not solely propagation-driven; rather, the duplexing scheme itself also plays a significant role. Even when TDD bands achieve higher or comparable MCS, FDD bands have a performance edge in the uplink due to the restrictive, downlink-heavy TDD architecture. These findings emphasize the indispensable role of low-frequency FDD spectrum in sustaining uplink capacity, providing insights that will help guide the design of next-generation wireless networks.

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arXiv2026

Evaluating Smartphone GNSS Accuracy for Geofenced 6 GHz Operations

The recently deployed 6 GHz spectrum in the U.S. utilizes distinct power categories, with the latest proposed "Geofenced Variable Power" (GVP) category permitting indoor and outdoor operations without continuous Automated Frequency Coordination (AFC) by relying instead on local databases of exclusion zones. Consequently, the safe operation of GVP devices depends entirely on reliable GNSS localization to respect these geofences. However, GNSS accuracy is highly variable and significantly degrades in environments like urban canyons or indoors. This paper presents the first comprehensive empirical study evaluating GNSS reliability specifically for GVP compliance. Utilizing the SigCap Android application, we document and compare GNSS accuracy across an extensive array of real-world conditions, encompassing urban versus suburban landscapes, varying mobility states (stationary, walking, driving), and indoor versus outdoor settings. The results demonstrate that while device hardware causes variations in GNSS accuracy, the operational environment is the primary driver of error. Indoor settings and dense urban areas consistently degrade localization. Moreover, outdoor positions adjacent to buildings often surprisingly produce significant inaccuracies, even near low-elevation structures. We further analyze the contribution of different GNSS constellations to device positioning and show that satellites from non-U.S.-licensed constellations-although currently used in a substantial portion of location fixes-are not permitted for regulatory geolocation under FCC requirements.

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