Ahmad Hassan

EEB 228

3650 McClintock Ave

Los Angeles, CA 90089

I am a Ph.D. student in the Electrical & Computer Engineering department at the University of Southern California. I am fortunate enough to be advised by Prof. Feng Qian. Topics that intrigue me include, but are not limited to, Mobile Systems, ML for Systems, 5G Mobile Networking, Multimedia Systems, and Networked VR/MR. My current research highlights challenges faced by today’s 4G/5G applications and argues for a cross-layer design to overcome these challenges.

Since the last few years, I have been working closely with Prof. Zhi-Li Zhang and Prof. Z. Morley Mao. Previously, I was an undergrduate student at the Lahore University of Management Sciences majoring in Computer Science, where I had a great time studying cellular networks and congestion control under the supervision of Prof. Zafar Ayyub Qazi.

*** I am looking for Summer 2025 internships. Please reach out at ahmadhas@usc.edu with any opportunities. Thank you! ***

news

Sep 18, 2024	Our work on 5G TDD Scheduling has been accepted to ACM CoNext 2024. Wait for details!
May 15, 2024	Our 5G Carrier Aggregation study led by Wei got into Sigcomm 2024!
Jan 03, 2024	Our OASIS work led by Shuowei was accepted to MMSys’24. Best paper award!
Jan 01, 2024	Our “QUIC is not Quick Enough over Fast Internet” paper led by Xumiao was accepted to TheWebConf24 (previously WWW).
Dec 15, 2023	Our smart band switching work has been accepted to HotMobile’24.

selected publications

CONEXT

Wixor: Dynamic TDD Policy Adaptation for 5G/xG Networks

Ahmad Hassan, Shivang Aggarwal, Mohamed Ibrahim, and 2 more authors

In Proceedings of the ACM CoNEXT 2024 Conference, 2024

PDF

SIGCOMM

Dissecting Carrier Aggregation in 5G Networks: Measurement, QoE Implications and Prediction

Wei Ye, Xinyue Hu, Steven Sleder, and 9 more authors

In Proceedings of the ACM SIGCOMM 2024 Conference, Sydney, NSW, Australia, 2024

DOI Bib PDF

@inproceedings{10.1145/3651890.3672251,
  author = {Ye, Wei and Hu, Xinyue and Sleder, Steven and Zhang, Anlan and Dayalan, Udhaya Kumar and Hassan, Ahmad and Fezeu, Rostand A. K. and Jajoo, Akshay and Lee, Myungjin and Ramadan, Eman and Qian, Feng and Zhang, Zhi-Li},
  title = {Dissecting Carrier Aggregation in 5G Networks: Measurement, QoE Implications and Prediction},
  year = {2024},
  isbn = {9798400706141},
  publisher = {Association for Computing Machinery},
  address = {New York, NY, USA},
  url = {https://doi.org/10.1145/3651890.3672250},
  doi = {10.1145/3651890.3672250},
  booktitle = {Proceedings of the ACM SIGCOMM 2024 Conference},
  pages = {340–357},
  numpages = {18},
  keywords = {carrier aggregation, 4G, 5G, network measurement, mobile network throughput prediction, deep learning},
  location = {Sydney, NSW, Australia},
  series = {ACM SIGCOMM '24},
}

NSDI

Habitus: Boosting Mobile Immersive Content Delivery through Full-body Pose Tracking and Multipath Networking

Anlan Zhang, Chendong Wang, Yuming Hu, and 5 more authors

In 21st USENIX Symposium on Networked Systems Design and Implementation (NSDI 24), Apr 2024

Bib PDF

@inproceedings{295677,
  author = {Zhang, Anlan and Wang, Chendong and Hu, Yuming and Hassan, Ahmad and Zhang, Zejun and Han, Bo and Qian, Feng and Xu, Shichang},
  title = {Habitus: Boosting Mobile Immersive Content Delivery through Full-body Pose Tracking and Multipath Networking},
  booktitle = {21st USENIX Symposium on Networked Systems Design and Implementation (NSDI 24)},
  year = {2024},
  isbn = {978-1-939133-39-7},
  address = {Santa Clara, CA},
  pages = {1677--1695},
  url = {https://www.usenix.org/conference/nsdi24/presentation/zhang-anlan},
  publisher = {USENIX Association},
  month = apr,
}

SIGCOMM
Vivisecting Mobility Management in 5G Cellular Networks

Ahmad Hassan, Arvind Narayanan, Anlan Zhang, and 7 more authors

In Proceedings of the ACM SIGCOMM 2022 Conference, Amsterdam, Netherlands, Apr 2022

Abs DOI Bib PDF Slides Website

With 5G’s support for diverse radio bands and different deployment modes, e.g., standalone (SA) vs. non-standalone (NSA), mobility management - especially the handover process - becomes far more complex. Measurement studies have shown that frequent handovers cause wild fluctuations in 5G throughput, and worst, service outages. Through a cross-country (6,200 km+) driving trip, we conduct in-depth measurements to study the current 5G mobility management practices adopted by three major U.S. carriers. Using this rich dataset, we carry out a systematic analysis to uncover the handover mechanisms employed by 5G carriers, and compare them along several dimensions such as (4G vs. 5G) radio technologies, radio (low-, mid- & high-)bands, and deployment (SA vs. NSA) modes. We further quantify the impact of mobility on application performance, power consumption, and signaling overheads. We identify key challenges facing today’s NSA 5G deployments which result in unnecessary handovers and reduced coverage. Finally, we design a holistic handover prediction system Prognos and demonstrate its ability to improve QoE for two 5G applications 16K panoramic VoD and realtime volumetric video streaming. We have released the artifacts of our study at https://github.com/SIGCOMM22-5GMobility/artifact.
@inproceedings{hassan2022vivisecting, author = {Hassan, Ahmad and Narayanan, Arvind and Zhang, Anlan and Ye, Wei and Zhu, Ruiyang and Jin, Shuowei and Carpenter, Jason and Mao, Z. Morley and Qian, Feng and Zhang, Zhi-Li}, title = {Vivisecting Mobility Management in 5G Cellular Networks}, year = {2022}, isbn = {9781450394208}, publisher = {Association for Computing Machinery}, address = {New York, NY, USA}, url = {https://doi.org/10.1145/3544216.3544217}, doi = {10.1145/3544216.3544217}, booktitle = {Proceedings of the ACM SIGCOMM 2022 Conference}, pages = {86--100}, numpages = {15}, keywords = {coverage, 5G, dataset, energy, handover, mobility, handover prediction, mobility management, network measurement, application performance}, location = {Amsterdam, Netherlands}, series = {SIGCOMM '22}, talk = {https://dl.acm.org/doi/10.1145/3544216.3544217}, }
SIGCOMM
A Variegated Look at 5G in the Wild: Performance, Power, and QoE Implications

Arvind ^*Narayanan, Xumiao ^*Zhang, Ruiyang Zhu, and 9 more authors

In Proceedings of the 2021 ACM SIGCOMM 2021 Conference, Virtual Event, USA, Apr 2021

Abs DOI Bib PDF Code

Motivated by the rapid deployment of 5G, we carry out an in-depth measurement study of the performance, power consumption, and application quality-of-experience (QoE) of commercial 5G networks in the wild. We examine different 5G carriers, deployment schemes (Non-Standalone, NSA vs. Standalone, SA), radio bands (mmWave and sub 6-GHz), protocol configurations (_e.g._ Radio Resource Control state transitions), mobility patterns (stationary, walking, driving), client devices (_i.e._ User Equipment), and upper-layer applications (file download, video streaming, and web browsing). Our findings reveal key characteristics of commercial 5G in terms of throughput, latency, handover behaviors, radio state transitions, and radio power consumption under the above diverse scenarios, with detailed comparisons to 4G/LTE networks. Furthermore, our study provides key insights into how upper-layer applications should best utilize 5G by balancing the critical tradeoff between performance and energy consumption, as well as by taking into account the availability of both network and computation resources. We have released the datasets and tools of our study at https://github.com/SIGCOMM21-5G/artifact.
@inproceedings{narayanan2021variegated, author = {Narayanan, Arvind and Zhang, Xumiao and Zhu, Ruiyang and Hassan, Ahmad and Jin, Shuowei and Zhu, Xiao and Zhang, Xiaoxuan and Rybkin, Denis and Yang, Zhengxuan and Mao, Zhuoqing Morley and Qian, Feng and Zhang, Zhi-Li}, title = {A Variegated Look at 5G in the Wild: Performance, Power, and QoE Implications}, year = {2021}, isbn = {9781450383837}, publisher = {Association for Computing Machinery}, address = {New York, NY, USA}, url = {https://doi.org/10.1145/3452296.3472923}, doi = {10.1145/3452296.3472923}, booktitle = {Proceedings of the 2021 ACM SIGCOMM 2021 Conference}, pages = {610--625}, numpages = {16}, keywords = {video streaming, mmWave, power characteristics, network measurement, power model, dataset, energy efficiency, latency, 5G}, location = {Virtual Event, USA}, series = {SIGCOMM '21}, talk = {https://dl.acm.org/doi/10.1145/3452296.3472923} }