Dartmouth logo Dartmouth College Computer Science
Technical Report series
CS home
TR home
TR search TR listserv
By author: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
By number: 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000, 1999, 1998, 1997, 1996, 1995, 1994, 1993, 1992, 1991, 1990, 1989, 1988, 1987, 1986

A Dynamically Refocusable Sampling Infrastructure for 802.11 Networks
Udayan Deshpande
Dartmouth TR2008-620

Abstract:

The edge of the Internet is increasingly wireless. Enterprises large and small, homeowners, and even whole cities have deployed Wi-Fi networks for their users, and many users never need to--- or never bother to--- use the wired network. With the advent of high-throughput wireless networks (such as 802.11n) some new construction, even of large enterprise build- ings, may no longer be wired for Ethernet. To understand Internet traffic, then, we need to understand the wireless edge.

Measuring Wi-Fi traffic, however, is challenging. It is insufficient to capture traffic in the access points, or upstream of the access points, because the activity of neighboring networks, ad hoc networks, and physical interference cannot be seen at that level. To truly understand the MAC-layer behavior, we need to capture frames from the air using Air Monitors (AMs) placed in the vicinity of the network. Such a capture is always a sample of the network activity, since it is physically impossible to capture a full trace: all frames from all channels at all times in all places.

We have built a monitoring infrastructure that captures frames from the 802.11 network. This infrastructure includes several "channel sampling" strategies that will capture repre- sentative traffic from the network. Further, the monitoring infrastructure needs to modify its behavior according to feedback received from the downstream consumers of the captured traffic in case the analysis needs traffic of a certain type. We call this technique "refocusing". The "coordinated sampling" technique improves the efficiency of the monitoring by utilizing the AMs intelligently.

Finally, we deployed this measurement infrastructure within our Computer Science building to study the performance of the system with real network traffic.

Note: Ph.D Dissertation. Advisor: David Kotz. Thesis Committee. David Kotz, Andrew Campbell, Chris Bailey-Kellogg, Brian Noble.


PDF PDF (1880KB)

Bibliographic citation for this report: [plain text] [BIB] [BibTeX] [Refer]

Or copy and paste:
   Udayan Deshpande, "A Dynamically Refocusable Sampling Infrastructure for 802.11 Networks." Dartmouth Computer Science Technical Report TR2008-620, May 2008.


Notify me about new tech reports.

Search the technical reports.

To receive paper copy of a report, by mail, send your address and the TR number to reports AT cs.dartmouth.edu


Copyright notice: The documents contained in this server are included by the contributing authors as a means to ensure timely dissemination of scholarly and technical work on a non-commercial basis. Copyright and all rights therein are maintained by the authors or by other copyright holders, notwithstanding that they have offered their works here electronically. It is understood that all persons copying this information will adhere to the terms and constraints invoked by each author's copyright. These works may not be reposted without the explicit permission of the copyright holder.

Technical reports collection maintained by David Kotz.