[talks] Swati Roy will present her General Exam Wednesday, May 4, 2016 in CS 302 at 2:30pm

[Nicki Gotsis]

The members of her committee are Nick Feamster (Adviser), Jennifer Rexford, and Kyle Jamieson.

Everyone is invited to attend her talk, and those faculty wishing to remain for the oral exam following are welcome to do so.   Please find her abstract and reading list below.

Abstract:

As smartphone users increasingly rely on cellular networks to access voice, video, and web applications, guaranteeing good performance and high availability is more important than ever. Historically, managing cellular network configuration has been a manual, error-prone process; recently, however, automated solutions such as SON (Self Organizing Networks) controllers are being deployed for dynamic tuning of network configuration. Self-organizing networks (SON) are a new paradigm in cellular networks that dynamically react to changes in network and traffic conditions, automatically adjusting the network configuration to improve performance for end users. For example, when a cell tower becomes congested, a SON controller might automatically tune the transmission power or antenna tilt of neighboring cell towers to better distribute load.  Large cellular network providers are currently deploying SON in their cellular networks to improve end-user performance for voice, video, and web applications. SON automates many aspects of cellular network configuration, but it is nonetheless susceptible to software bugs.  Additionally, if it is configured incorrectly, it may provide suboptimal performance for particular network conditions and traffic load. One of the biggest challenges in SON configuration is determining how a configuration change affects the performance that end users experience. Existing systems are based on classic time-series prediction, and compare the performance between a study group (where a particular configuration change was implemented) and a control group (where the change was not implemented) to tackle the impact of external factors or rely on comparisons of a particular configuration change against a baseline. Yet, because a SON controller operates in a dynamic environment, isolating the effects of any single configuration change against a control group or a baseline is incredibly difficult.  We propose a capability (Veracity) to analyze and quantify the performance effects of SON actions. Assessing the effects of SON control is difficult because of the dynamic nature of SON and the dependency of end-user performance on factors such as radio channel quality, mobility and traffic load. Veracity addresses these using model-driven impact detection and quantification. Our evaluation using data collected from an operational cellular network demonstrates that Veracity is accurate. Veracity is now being used by the service providers' field operation teams for the assessment of SON effectiveness in arenas and stadiums.

Reading List:

[1] Ajay Mahimkar, Han Hee Song, Zihui Ge, Aman Shaikh, Jia Wang, Jennifer Yates, Yin Zhang, Joanne Emmons: Detecting the performance impact of upgrades in large operational networks. In ACM SIGCOMM, 2010.

[2] A. Mahimkar, Z. Ge, J. Yates, C. Hristov, V. Cordaro, S. Smith, J. Xu, and M. Stockert: Robust assessment of changes in cellular networks. In ACM CoNEXT, 2013.

[3] M. Shafiq, L. Ji, A. Liu, J. Pang, S. Venkataraman, and J. Wang: A first look at cellular network performance during crowded events. In SIGMETRICS, 2013.

[4] M. Zubair Shafiq, Lusheng Ji, Alex X. Liu, Jia Wang: Characterizing and Modeling Internet Traffic Dynamics of Cellular Devices, In SIGMETRICS, 2011. 

[5] S. Sundaresan, W. de Donato, N. Feamster, R. Teixeira, S. Crawford, and A. Pescape: Broadband Internet Performance: A View From the Gateway . In SIGCOMM, Aug. 2011.

[6] Srikanth Sundaresan , Nick Feamster , Renata Teixeira: Measuring the Performance of User Traffic in Home Wireless Networks. In PAM, 2015

[7] Mingzhe Li, Feng Li, Mark Claypool, and Robert Kinicki: Weather Forecasting - Predicting Performance for Streaming Video over Wireless LANs, In NOSSDAV, June 2005.

[8] Naga Katta, Haoyu Zhang, Michael Freedman, and Jennifer Rexford. Ravana: Controller Fault-Tolerance in Software-Defined Networking, In SIGCOMM Symposium For SDN Research (SOSR), June 2015. 

[9] Athula Balachandran, Vaneet Aggarwal, Emir Halepovic, Jeffrey Pang, Srinivasan Seshan, Shobha Venkataraman, He Yan: Modeling Web Quality-of-Experience on Cellular Networks. In MobiCom 2014.

[10] Xin Jin, Li Erran Li, Laurent Vanbever, and Jennifer Rexford. SoftCell: Scalable and Flexible Cellular Core Network Architecture. In CoNext 2013. 

[11]  L. L. Peterson and B. S. Davie. Computer Networks, Fifth Edition: A Systems Approach. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 5th edition, 2011. 

Best,
Swati