Design and evaluation of a real-time locating system for wireless sensor networks

摘要

Evaluating target-tracking protocols for wireless sensor networks that canrnlocalise multiple mobile assets can be a very challenging task. Such protocolsrnusually aim at the minimisation of communication overhead, data processing forrnthe participating nodes and delivering adequate tracking information of thernmobile assets in a timely manner. Simulations on such protocols are performedrnusing theoretical models that are based on unrealistic assumptions like the unitrndisc graph communication model, ideal network localisation and perfectrndistance estimations. With these assumptions taken for granted, theoreticalrnmodels claim various performance milestones that cannot be achieved inrnrealistic conditions. In this paper, we design a new localisation protocol, wherernmobile assets can be tracked passively via software agents. Moreover, wernaddress and mitigate issues that hinder performance over the wireless mediumrnand provide a fully deployable protocol. The design, implementation andrnexperimentation of this new protocol along with further optimisations werernperformed using the WISEBED framework. We apply our protocol in a realrnindoor wireless sensor testbed with multiple experimental scenarios to showcasernscalability and trade-offs between network properties and configurable protocolrnparameters. By analysis of the real-world experimental output, we presentrnresults that depict a more realistic view of the target tracking problem, regardingrnpower consumption and the quality of tracking information. Finally, we alsornconduct some much focused simulations to assess the scalability of our protocolrnin very large networks and multiple mobile assets.