Systems & networking

Vijay Vasudevan, Amar Phanishayee, Hiral Shah, Elie Krevat, David G. Andersen, Gregory R Ganger , Garth A Gibson, Brian Mueller

ACM SIGCOMM 2009 | August 2009

Victor Bahl, Ranveer Chandra, Patrick Lee, Vishal Mishra, Jitu Padhye, Dan Rubenstein, Yan Yu

IEEE/ACM Transaction on Networking | August 2009, Vol 17(4): pp. 1160-1171

Currently deployed IEEE 802.11WLANs (Wi-Fi networks) share access point (AP) bandwidth on a per-packet basis. However, the various stations communicating with the AP often have different signal qualities, resulting in different transmission rates. This induces a phenomenon known as the rate anomaly problem, in which stations with lower signal quality transmit at lower rates and consume a significant majority of airtime, thereby dramatically reducing the throughput of stations transmitting at high rates. We propose a practical, deployable system, called SoftRepeater, in which stations cooperatively address the rate anomaly problem. Specifically, higher-rate Wi-Fi stations opportunistically transform themselves into repeaters for stations with low data-rates when transmitting to/from the AP. The key challenge is to determine when it is beneficial to enable the repeater functionality. In this paper, we propose an initiation protocol that ensures that repeater functionality is enabled only when appropriate. Also, our system can run directly on top of today’s 802.11 infrastructure networks. We evaluate our system using simulation and testbed implementation, and find that SoftRepeater can improve cumulative throughput by up to 200%.

Project Project

Ramya Raghavendra, Jitu Padhye, Ratul Mahajan, Elizabeth Belding

MSR-TR-2009-108 | August 2009

Moez Draief, Milan Vojnovic

MSR-TR-2009-86 | August 2009

Proceedings of the Eighteenth Conference on Uncertainty in Artificial Intelligence (UAI2002)

Project

Dan Suciu, Raghav Kaushik

International Conference on Very Large Data Bases | August 2009

International Conference on Very Large Data Bases

Srikanth Kandula, Jitu Padhye, Victor Bahl

MSR-TR-2009-109 | August 2009

Galen Reeves, Jie Liu, Suman Nath, Feng Zhao

VLDB ‘2009: Proceedings of 35th Conference on Very Large Data Bases | August 2009

VLDB '2009: Proceedings of 35th Conference on Very Large Data Bases

Marcos K. Aguilera, Idit Keidar, Dahlia Malkhi, Alexander Shraer

Proceedings of the ACM Symposium on Principles of Distributed Computing (PODC) | August 2009

Martin Labrecque, J. Gregory Steffan, Geoffrey Salmon, Manya Ghobadi, Yashar Ganjali

August 2009

2nd Place for Best Project Awards

Yossi Azar, Uriel Feige, Iftah Gamzu, Thomas Moscibroda, Prasad Raghavendra

SPAA 2009: 21st ACM Symposium on Parallelism in Algorithms and Architectures, Calgary, Alberta, Canada | August 2009