The mistaken axioms of wireless-network research
David F. Kotz, Calvin C. Newport, Chip Elliott · 2003
Most research on ad-hoc wireless networks makes sim-plifying assumptions about radio propagation. The “Flat Earth ” model of the world is surprisingly popular: all ra-dios have circular range, have perfect coverage in that range, and travel on a two-dimensional plane. CMU’s ns-2 radio models are better but still fail to represent many aspects of realistic radio networks, including hills, obstacles, link asymmetries, and unpredictable fading. We briefly argue that key “axioms ” of these types of prop-agation models lead to simulation results that do not ad-equately reflect real behavior of ad-hoc networks, and hence to network protocols that may not work well (or at all) in reality. We then present a set of 802.11 mea-surements that clearly demonstrate that these “axioms” are contrary to fact. The broad chasm between simula-tion and reality calls into question many of results from prior papers, and we summarize with a series of recom-mendations for researchers considering analytic or simu-lation models of wireless networks. 1