An Approach for Filtering Inaccurate Access Point Observation Report in WiFi Positioning System

WiFi Positioning System (WPS) plays important role in Ubiquitous applications. It shows shorter response time than GPS and provides more precise position than Cell towers. It is widely used in hybrid positioning systems, e.g. GPS and WPS. The main problem of WPS is how to collect WiFi Access Point (AP) positions because the most of AP positions are not published. So thus, WPS providers collect AP positions by themselves or rely on the WPS user´s report. There are several WPS provided, some are commercial system and the others are voluntarily provided. Outdoor position estimation method are already established in commercial system, however, the indoor case requires some more researches. It is necessary to keep voluntarily WPSs. In this paper, we propose an open method to select precise position reported by users to keep WPS estimation accuracy. The proposed method is basically based on the precision preservation methods used in GPS. WPS does not have the same degree of accuracy as GPS, it should be verified the effectiveness in WPS. We have some consideration about the applicability of the proposed method.