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<div class="elementToProof">This is an announcement of Muhammad Iqbal Rochman's Dissertation Defense.<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Candidate: Muhammad Iqbal Rochman<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Date: Monday, April 01, 2024<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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<div class="elementToProof">Time: 9 am CT</div>
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</span>Remote Location: <a href="https://uchicago.zoom.us/j/91496723089?pwd=SFZyaHc2WlY0SGwrYmJuRG54d1E4dz09" id="OWA7e6c4197-c0fd-030c-5913-05a35c3c7eca" class="OWAAutoLink">https://uchicago.zoom.us/j/91496723089?pwd=SFZyaHc2WlY0SGwrYmJuRG54d1E4dz09</a> Meeting
ID: 914 9672 3089 Passcode: 603129<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Location: JCL 298<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Title: Performance Evaluation of Wireless Networks Using Device-based Measurement<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Abstract: Traditional methods for measuring cellular and wireless network performance, like simulations and lab experiments, often fail to capture the complexities of real-world deployments. Device manufacturers and network operators may face practical
or economic limitations that prevent them from fully implementing network capabilities. This can include optional features like Multiple User MIMO (MU-MIMO) or massive MIMO, which may be omitted as long as basic device compatibility is maintained. The resulting
lack of clarity on actual network performance highlights the need for independent, academic measurement reports on deployed wireless networks, free from the influence of commercial operators. Our research investigates the design, approaches, and challenges
of using consumer devices as viable tools for wireless performance measurement. We explored methodologies for extracting data using both standard device Application Programming Interfaces (APIs) and root-access capabilities. Our findings demonstrate that
this device-based methodology is both sufficient and scalable for characterizing previous-generation (4G and Wi-Fi 5/802.11ac) and current-generation (5G and Wi-Fi 6e) wireless networks, including their unique spectrum and feature sets.<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Our methodology effectively measures the performance of newly deployed 5G networks in high-band/mmWave (>24 GHz) and mid-band (1-6 GHz), revealing crucial insights: (1) While we confirm the Gigabit-level downlink (DL) throughput of mmWave networks as
advertised by operators, it suffers from limited range due to high-frequency signal fading. This necessitates dense and costly network infrastructure. Furthermore, indoor penetration, even with line-of-sight, is hampered by low-emission glass. Additionally,
device thermal limitations can throttle throughput; and (2) The mid-band deployments, on the other hand, provide a balance of coverage and performance with a median of 200 Mbps DL throughput using a single 100~MHz channel, reaching 1~Gbps when aggregating
multiple channels. This surpasses the median 31 Mbps achieved with a 20 MHz 4G mid-band channel. However, this improvement appears to be driven only by increased bandwidth availability. Moreover, we observe adjacent channel interference between 4G and 5G mid-band,
likely due to insufficient guard bands and mismatched TDD configurations. These findings underscore the importance of additional spectrum for future 6G networks. However, operators and device manufacturers should emphasize the implementation of new 5G features
like MU-MIMO and higher modulation for optimal performance.<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Beyond cellular networks, our methodology has proven valuable in evaluating the newly released unlicensed 6 GHz spectrum utilized by Wi-Fi 6E. While current regulations mandate low-power indoor (LPI) deployments to protect incumbent fixed links, concerns
persist regarding potential interference. Our extensive measurement campaigns across two university campuses indicate outdoor RSSI values between -64 and -95 dBm (median -89~dBm). Additionally, we observed building entry loss (BEL) of 12-16 dB through double-pane
low-emission windows and 25-33 dB through solid brick walls. Notably, only 5% of indoor BSSIDs were detectable outdoors. These findings suggest a low risk of interference to incumbent fixed links. However, further research is warranted to determine appropriate
signal levels for the proposed client-to-client (C2C) mode in future Wi-Fi 7 specifications.<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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</span>Advisors: Monisha Ghosh<span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class=""><br class="">
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<div class="elementToProof">Committee Members: Heather Zheng, Nick Feamster, and Monisha Ghosh</div>
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