Measurement-Driven Modeling of Wireless Link Capacity

This work is being done with collaboration between NEC Labs, Princeton, NJ and WINGS Lab at SUNY, Stony Brook, NY.

The goal of the project is to create a practical, empirically derived, measurement-based model of the capacity of a link in 802.11-based wireless networks. We do link-quality measurements on a testbed to determine delivery ratio and received signal strengths of each link. These measured parameters are then modeled into metrics that quantify interference between nodes and links. The interference model thus created is used to model the capacity of a link.

For example, in the above figure, consider a set of active links (CA, BD and EF) carrying a certain amount of traffic at a specified rate. Our goal is to create a model that can predict the capacity of any given link (e.g. BC or AB), i.e., the maximum amount of traffic that can be pushed on that link. We want to do this for an actual deployed network. Thus, purely theoretical models are not sufficient.

Here, you will find our testbed details, our software, and some data for our testbed.

This Applet demonstrates the working of our calculations for the NEC Labs Mesh Testbed.

Anand Kashyap Anand Kashyap

Samir Das

Samrat Ganguly

• “A Measurement-Based Approach to Modeling Link Capacity in 802.11-based Wireless Networks,” Anand Kashyap, Samrat Ganguly and Samir Das. Proc. ACM MobiCom, Montreal, Sept 2007. PDF
• “A Measurement-Based Model for Estimating Transmission Capacity in a Wireless Mesh Network,” Anand Kashyap, Samrat Ganguly and Samir Das. Poster in ACM WiNTech, Los Angeles, Sept 2006. PDF PPT
• “Characterizing Interference in 802.11-based Wireless Mesh Networks,” Anand Kashyap, Samrat Ganguly and Samir Das. Technical Report, 2006 PDF