Topology realization using gain control for wireless testbeds

Abstract

Wireless testbeds present a convenient and cost effective option for researchers in communications to validate their work. The main drawback of these testbeds is their reliance on nodes with fixed placement; this limits experimenters ability to test protocols that depend on a complex connectivity between the nodes such as relaying. In this work, we present a way to over-come this limitation; this method attempts to realize a given topology between a set of nodes by adjusting each node's transmit power and receive gain in a manner to connect and disconnect the links between the nodes as desired. We start by expressing the topology realization as an optimization problem using two different forms. The topology realized is dependent on some characteristics of radio-frequency (RF) hardware. Hence, we evaluate theses parameters for a specific platform. A computer evaluation for the two formulations is carried out, followed by a real world experiment to validate the proposed method. During this experiment, the values of gains required to realize a given topology are calculated, then tested using hardware.