LAUSR

While localization is essential to many applications, there are quantities of wireless nodes whose accurate locations remain unknown or hard to tell. As a remedy, this paper is leveraging a GPS-capable Android handset that features portability and sufficient computing capability to collect data and display localization results thereof. Our objective is to locate the unknown nodes under irregular radio coverage. To this end, we first devise a range-free approach that computes the most likely circumcenter from a convex polygon representative of radio coverage. Preliminary simulations corroborate the effectiveness of our development. Then the first approach is simplified by allowing for received signal strengths with the notion of estimative regions, namely rectangular areas enclosing an unknown node, to refine the area of interest for localization. Free from involved computations, our treatment mitigates the errors of estimation resulting from different radio signal propagation scenarios, by taking an additional parameter for ameliorating localization accuracy. Field experiments were conducted to demonstrate performance results overlying Google Maps on the handset and through quantitative comparisons in different settings. Performance results show that our development can get fielded in practice.