A scalable dual-radio wireless testbed for emulating mesh networks

In this paper, we introduce and evaluate ScaleMesh, a scalable miniaturized dual-radio wireless mesh testbed based on IEEE 802.11b/g technology. ScaleMesh can emulate large-scale mesh networks within a miniaturized experimentation area by adaptively shrinking the transmission range of mesh nodes by means of variable signal attenuators. To this end, we derive a theoretical formula for approximating the attenuation level required for downscaling desired network topologies. We conduct a comprehensive performance study, in which we validate the feasibility of ScaleMesh for network emulation and protocol evaluation. Among others, we study the effect of channel selection, signal attenuation level, different topologies, and traffic load on network performance. We particularly focus on the performance of single-radio versus dual-radio communication, while investigating key parameters which can provide a substantial improvement in performance. We show that dual-radio communication improves network goodput by up to 100%, yet does not overcome TCP’s fairness problems over IEEE 802.11.