Campus Event Calendar
Event Entry
What and Who
"Using Redundancy to Enable Interactive Communication for Moving Vehicles"
Ratul Mahajan
Microsoft Research, Redmond
SWS Colloquium
Ratul Mahajan is a Researcher at Microsoft Research. His research
interests include all aspects of networked systems, especially their
architecture and design. His work spans Internet routing and measurements,
incentive-compatible protocol design, practical models for wireless
networks, and vehicular networks. He has published several highly-cited
papers in top-tier venues such as SIGCOMM, SOSP, and NSDI. He is a winner
of the SIGCOMM best paper award, the William R. Bennett Prize, and
Microsoft Research Graduate Fellowship. He obtained his Ph.D. from the
University of Washington (2005) and B.Tech. from Indian Institute of
Technology, Delhi (1999).
SWS, RG1
Expert Audience
English
Note: We use this to send email in the morning.
Date, Time and Location
Monday, 13 July 2009
14:00
60 Minutes
E1 5
5th floor
Saarbrücken
Abstract
Through extensive measurements of wireless connectivity from moving
vehicles, I find that packet loss creates significant performance issues
for interactive applications. This poor performance exists for both WLAN
technologies (e.g., WiFi) and WWAN technologies (e.g., 3G and WiMax).
Unlike wired networks, in wireless networks priority-based queuing is not
sufficient to reduce packet loss for loss-sensitive applications. I
propose that losses should instead be masked through aggressive but
controlled use of available redundancy, and I describe two such systems.
The first system, called ViFi, targets the use of WiFi from moving
vehicles. Current WiFi handoff methods, in which clients communicate with
one base station at a time, lead to frequent disruptions in connectivity.
ViFi leverages the presence of redundant in-range base stations to reduce
disruptions and improve application performance. The second system, called
PluriBus, targets the use of 3G or WiMax from moving vehicles. PluriBus
leverages the spare capacity in the wireless channel using a novel erasure
coding method. In my experiments, each system improves the performance of
interactive applications by at least a factor of 2.
Contact
Brigitta Hansen
0681 - 9325691
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Brigitta Hansen, 07/06/2009 14:43 -- Created document.