NeTS: Small: Tools for Large-Scale Network Testbed Experimentation

Arizona State University, Scottsdale AZ

Investigators

Abstract

Over the last decade, the use of wireless Internet-connected devices has nearly doubled in the U.S., with users fueling new socially useful applications. Despite being expected to behave predictably under a wide set of circumstances, these engineered networks have complex behaviors, exhibiting characteristics not easily studied using traditional techniques. Experimentation is one way to improve our understanding. Among the many parameters of the network, the devices, and the environment, a necessary first step in experimentation is screening to select those that significantly impact performance for follow-on study. This project contributes to the national interest by developing tools integrated with test-beds to address grand challenges in wireless networks. The minimum requirements for screening in this setting are captured in a locating array (LA). LAs exhibit logarithmic growth in the number of parameters, making practical the consideration of an order of magnitude more parameters in experimentation. The structure of the LA and the analysis to recover the significant parameters and two-way interactions impacting the measured performance are tightly coupled. While the basic requirements of screening are known, the basic requirements of recovery are not well understood. If balance is required, then the Rao bound applies, and the array size must grow polynomially in the number of parameters and two-way interactions. Approaches include either making the recovery algorithm work with the lack of balance in the LA, or making the LA more suitable for recovery. Practical networking applications motivate new structure on the LA that in turn impacts recovery. The goals of this project are to produce tools integrated with testbeds (1) to generate and validate screening designs for large-scale test-bed experimentation, and (2) for their subsequent analysis. This project advances research in two primary areas: (1) Understanding the requirements for recovery, and the trade-offs in array structure and recovery, thus helping to build a bridge between novel LAs and traditional screening designs. (2) The effective use of screening designs requires the deployment of tools to support them. Novel open source tools to construct, verify, and analyze LAs will be developed and integrated in a wireless network test-bed. The tools will be made available in a community wide repository, equipped with documentation and training materials, including steps to integrate them with a variety of test-beds. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.