CS 638: Multimedia Networking and Operating Systems

Fall 2026

Course Description and Learning Outcomes:

Have you wondered how AI and immersive computing can be synergistic? This course explores the latest and open research problems in multimedia networking and operating systems, with several example case studies such as YouTube, Netflix, Zoom, VR Chat. We will also be exploring the role of AI, e.g., in augmented reality (AR).

The topics to be covered (tentatively) include:

  1. Multimedia applications, such as video streaming, video conferencing, and extended (e.g., augmented, virtual) reality/immersive computing, their infrastructure/resource requirements, and assessing their user quality of experience
  2. Multimedia formats and compression, e.g., H.264, AAC, point clouds, polygon meshes, 3D Gaussian splats
  3. Multimedia network traffic characteristics, traffic engineering, and protocols to transport multimedia traffic and control congestion, e.g., QUIC, DASH, RTP
  4. Content distribution networks and edge clouds, e.g., Akamai, Netflix OpenConnect, Zoom data centers
  5. End system resource management, e.g., real-time scheduling
  6. AI, ML, and LLMs for multimedia and extended reality applications, e.g., video analytics, generative models
  7. Multimedia over Wi-Fi and cellular networks

Upon completion of this course, students will grasp key multimedia/extended reality networking and operating systems concepts, requirements, and challenges, and several current and recently proposed solutions.

Days/Time:

TTh 10:30--11:45 AM

Room:

LWSN B134

Instructor:

Sonia Fahmy, office: LWSN 2142H, e-mail: last name @purdue.edu
Please post privately on edstem.org if you wish to set up an appointment to meet online or in-person.

Handouts, including lecture notes, will be posted on the edstem.org Resoures page (click on the down arrow in the top row of the course page on edstem.org).

Please make sure that you check edstem.org and your Purdue e-mail frequently (at least once a day). Please do not post answers to the assignments, though posting general clarifications is fine.

Prerequisites:

CS 503 or CS 536 or consent of the instructor

Credit:

03

Policies:

Academic Integrity

Please review the page maintained by Professor Gene Spafford for information about academic integrity.

Due Dates

All assignments/reports/reviews are due on the dates and times specified. It is the responsibility of the students to manage their time so that required work can be submitted before the deadline.

Attendance and Classroom Policy

Class participation and discussions are strongly encouraged. However, please be considerate to others: avoid coming to class late, leaving early, talking to other students, etc. Please turn off your cell phone or make it silent before the class starts.

Emergency Policy

In the event of a major campus emergency, course requirements, deadlines and grading percentages are subject to changes that may be necessitated by a revised semester calendar or other circumstances. Any changes will be posted on edstem.org.

AI Policy

Use of AI tools in this course is permitted without restrictions, but each student is responsible for fully understanding, validating, and being able to explain outputs of AI tools; otherwise, a grade penalty may be incurred. It is required to disclose the use of AI tools.

Non-discrimination Statement and Accessibility

Purdue University is committed to maintaining a community which recognizes and values the inherent worth and dignity of every person; fosters tolerance, sensitivity, understanding, and mutual respect among its members; and encourages each individual to strive to reach his or her own potential. In pursuit of its goal of academic excellence, the University seeks to develop and nurture diversity. The University believes that diversity among its many members strengthens the institution, stimulates creativity, promotes the exchange of ideas, and enriches campus life. More details are available on Brightspace table of contents, under University Policies.

Purdue University strives to make learning experiences as accessible as possible. If you anticipate or experience physical or academic barriers based on disability, you are welcome to let me know so that we can discuss options. You are also encouraged to contact the Disability Resource Center at: drc@purdue.edu or by phone: 765-494-1247. More details are available on Brightspace under Accessibility Information.

Mental Health/Wellness

If you are experiencing stress or personal problems, Purdue provides counseling services through the Purdue CAPS Center. Please see https://www.purdue.edu/CAPS/ for more details.

Learning Resources:

We will cover some material from the following books, but they are not required, i.e., your class notes will suffice:

We will also discuss important and recent papers on multimedia and extended reality in top networking and operating systems conferences, journals, and magazines.

Discussion Lead and Reviews: Each student will lead the discussion of *one* of the assigned papers. The presentation should discuss the main ideas of the paper, in addition to pointing out their significance/novelty, applications, limitations, and relationship to other work. The student leading the discussion is expected to prepare original slides on the strengths and weaknesses of the paper, with suggestions for improvement/extension. Please credit the source of any slide or figure you use that is not original.

Since one of the aims of this course is to learn to critique research papers, students will complete reviews of assigned papers before their discussion. This means that students should read these assigned papers critically and carefully. Please be prepared to discuss your review in class.

Tentative Grading Plan:

Homeworks and best *five* paper reviews 35%
Paper presentation 15%
Project plan and updates 10%
Project report 25%
Project presentation 10%
Class participation 5%

We will use Gradescope to submit homeworks, paper reviews, and project documents.

Tentative Course Schedule:

Date Topic/Reading(s) Due
Aug. 25 Course overview; Examples (Netflix; Netflix presentation at FAST '21; Google Networking; GGN; Zoom)
Aug. 27 Multimedia units and streams, real-time systems, Quality of Experience (QoE) and Quality of Service (QoS)
Sept. 1 Review of key systems and networking concepts
Sept. 3 Review of key systems and networking concepts (cont'd)
TCP throughput (no slow start); TCP throughput (with slow start); Fairness index; Fairness/efficiency; Equation-based congestion control
Sept. 8 Audio, video, and real-time protocols
Henning Schulzrinne and Jonathan Rosenberg, Internet Telephony: Architecture and Protocols-- An IETF Perspective, Computer Networks and ISDN Systems, vol 31, no 3, pp. 237-255, February 1999.
Sept. 10 Audio, video, and real-time protocols (cont'd)
Sept. 15 Network traffic management
Sept. 17 Network traffic management (cont'd)
Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye, Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan. 2010. Data center TCP (DCTCP). SIGCOMM Comput. Commun. Rev. 40, 4 (October 2010), 63-74.
RFC 9330 | RFC 9331 | RFC 9332 		Homework 1 due by 8 PM
Sept. 22 Network traffic management (cont'd); Content distribution networks and peer-to-peer systems
Sept. 24 Content distribution networks and peer-to-peer systems (cont'd)
Open Connect Everywhere: A Glimpse at the Internet Ecosystem through the Lens of the Netflix CDN. ACM SIGCOMM Computer Communications Review, 48(1), January 2018. 		Project plan due by 8 PM
Sept. 29 QUIC
(1) Adam Langley, Alistair Riddoch, Alyssa Wilk, Antonio Vicente, Charles Krasic, Dan Zhang, Fan Yang, Fedor Kouranov, Ian Swett, Janardhan Iyengar, Jeff Bailey, Jeremy Dorfman, Jim Roskind, Joanna Kulik, Patrik Westin, Raman Tenneti, Robbie Shade, Ryan Hamilton, Victor Vasiliev, Wan-Teh Chang, and Zhongyi Shi. The QUIC Transport Protocol: Design and Internet-Scale Deployment. SIGCOMM '17. pp. 183-196. [Click here for the slides]
(2) J. Iyengar, M. Thomson, QUIC: A UDP-based multiplexed and secure transport, RFC 9000, May 2021.
(3) C. Perkins and J. Ott, Real-time Audio-Visual Media Transport over QUIC EPIQ'18: Proceedings of the Workshop on the Evolution, Performance, and Interoperability of QUIC December 2018 Pages 36-42.
(4) Mirko Palmer, Malte Appel, Kevin Spiteri, Balakrishnan Chandrasekaran, Anja Feldmann, and Ramesh K. Sitaraman. 2021. VOXEL: cross-layer optimization for video streaming with imperfect transmission. In Proceedings of the 17th International Conference on emerging Networking EXperiments and Technologies (CoNEXT '21). Association for Computing Machinery, New York, NY, USA, 359-374.
Oct. 1 QUIC (cont'd) Homework 2 due on Sunday, Oct. 4, by 8 PM
Oct. 6 Video conferencing
Nathaniel Cherian, Akhil Prasad, Sonia Fahmy, "A Microscopic View of Congestion Control Behavior in Video Conferencing Applications," In Proc. of Passive and Active Measurement Conference (PAM), pp. 152-167, March 2026. [Link to Proceedings]
Oct. 8 Panoramic videos, volumetric videos, and extended reality
(1) Gustavo de Veciana, Sonia Fahmy, George Kesidis, Voicu Popescu. Ten Ways in which Virtual Reality Differs from Video Streaming, 7 pp., 2024.
(2) Voicu Popescu, George Kesidis, Gustavo de Veciana, Sonia Fahmy, "Benchmarking Extended Reality Systems," in IEEE Internet Computing, vol. 29, no. 6, pp. 7-14, Nov.-Dec. 2025, [PDF].
(3) Mijanur R. Palash, Voicu Popescu, Amit Sheoran, Sonia Fahmy, "Robust 360 Video Streaming via Non-Linear Sampling," In Proceedings of IEEE INFOCOM (the conference on computer communications), 10 pp., May 2021. [PDF]
(4) Umakant Kulkarni, Khaled Diab, Lianjie Cao, Faraz Ahmed, Shivang Aggarwal, Puneet Sharma, Sonia Fahmy, "Maestro: QoE-Aware Dynamic Resource Allocation in Wi-Fi Networks," Proc. ACM Netw. 3, CoNEXT1, Article 4 (March 2025), 24 pages. [PDF]
(5) Yufeng Chen, Umakant Kulkarni, Voicu Popescu, Sonia Fahmy, "RUN: A Case for Cross-Layer Networked Virtual Reality," In Proceedings of the 33rd ACM International Conference on Multimedia (MM '25), pp. 12111-12120, October 27-31, 2025, Dublin, Ireland, 2025. [PDF]
Oct. 15 Panoramic videos, volumetric videos, and extended reality (cont'd)
Oct. 20 Multimedia and real-time operating systems
(1) C. L. Liu and James W. Layland. Scheduling algorithms for multiprogramming in a hard-real-time environment, Journal of the Association for Computing Machinery, volume 20, number 1, January 1973, pp. 46-61.
(2) A. L. N. Reddy and J. Wyllie. Disk scheduling in a multimedia I/O system. In Proceedings of ACM Multimedia '93, Anaheim, CA, 225-234, August 1993.
(3) D. J. Gemmell, H. M. Vin, D. D. Kandlur, P. Venkat Rangan and L. A. Rowe, Multimedia Storage Servers: A Tutorial in Computer, vol. 28, no. 5, pp. 40-49, May 1995.
Homework 3 due by 8 PM
Oct. 22 Multimedia and real-time operating systems (cont'd)
Oct. 27 Ammar Tahir, Prateesh Goyal, Yongzhou Chen, and Radhika Mittal. Queueless and Lossless Rate Control. In Proceedings of SIGCOMM 2026. Discussion lead: Mahir Rahman; Paper review due by 10:00 AM
Oct. 29 Jin Heo, Vic Wang, Ketan Bhardwaj, and Ada Gavrilovska. Stimpack: An Adaptive Rendering Optimization System for Scalable Cloud Gaming. In Proceedings of NSDI 2026. Discussion lead: Ruibing Feng; Paper review due by 10:00 AM
Nov. 3 Zili Meng, Xiao Kong, Jing Chen, Bo Wang, Mingwei Xu, Rui Han, Honghao Liu, Venkat Arun, Hongxin Hu, and Xue Wei. Hairpin: Rethinking Packet Loss Recovery in Edge-based Interactive Video Streaming. In Proc. of 21st USENIX Symposium on Networked Systems Design and Implementation (NSDI 24), pp. 907--926. Discussion lead: Shyam Gopal Vemulapalli; Paper review due by 10:00 AM
Nov. 5 Jing Wang, Xiao Kong, Yunzhe Ni, Nian Wen, Jiaxing Zhang, Congcong Miao, and Honghao Liu. From Source to Solution: Tackling Packet Losses in Large-scale Cloud Gaming Systematically and Precisely. In Proceedings of NSDI 2026. Discussion lead: Daniyal Bekinalkar; Paper review due by 10:00 AM
Nov. 10 Guest speakers: Dr. Amber Johnson Avery and Nilofer Rajpurkar, Purdue alumni. Project update due
Nov. 12 Hua Meng, Yufan Zhuang, Yasna Noushirvani, Xiangjie Huang, and Zili Meng. MAE: More Adaptive Video Encoder for Consistent Low Latency in High-Quality Real-Time Communication. In Proceedings of NSDI 2026. Discussion lead: Shriya Anil; Paper review due by 10:00 AM
Nov. 17 Dehui Wei, Jiao Zhang, Haozhe Li, Rui Han, Zhichen Xue, Yajie Peng, Xiaofei Pang, Yan Ma, and Jialin Li. HyperEdge: An Edge CDN Infrastructure for Cost Efficient Video Streaming. In Proceedings of NSDI 2026. Discussion lead: Duong Dinh; Paper review due by 10:00 AM
Nov. 19 Le Zhang, Tong Meng, Bingcong Lu, Jinghao Yuan, Lu Chen, Huanting Liu, Lei Xiao, Nailiang Wu, Zhou Sha, Changqing Yan, Jianrong Zhang, Jianxin Kuang, and Li Song. Adaptive Bitrate Live Streaming over HTTP-FLV: A Practical System Perspective. In Proceedings of SIGCOMM 2026. Discussion lead: Alejandro Griffith; Paper review due by 10:00 AM
Nov. 24 Brent Zoomers, Maarten Wijnants, Ivan Molenaers, Joni Vanherck, Jeroen Put, Lode Jorissen, and Nick Michiels. PRoGS: Progressive Rendering of Gaussian Splats. In Proceedings of 2025 IEEE/CVF Winter Conference on Applications of Computer Vision (WACV). Discussion lead: Dhruv Chanana; Paper review due by 10:00 AM
Dec. 1 Review and discussion
Dec. 3 Review and discussion
Dec. 8 Project presentations (Duong/Ruibing, Shriya, Alejandro)
Dec. 10 Project presentations (Daniyal, Shyam, Dhruv) Final project report due Dec. 16th, 2026 by 8 PM