Quantitative comparison of indoor positioning on different densities of WiFi arrays in a single environment

Abstract

Location Based Services (LBS), which are supported by ubiquitous location finding and positioning information, have become increasingly popular. These services are integrated with various wireless technologies (i.e. cellular, WiFi, and Bluetooth) on mobile devices that establish necessary location information. While each of these technologies contributes to the integration, development and success of LBSs, WiFi has been the most widely employed as an alternative to the Global Positioning System (GPS). Several commercial WiFi-based positioning systems (WPS) are available to the public to extend positioning coverage to places where GPS is unreliable or unavailable; however, these commercial WPSs often fail to deliver GPS-like positioning. The coarse positioning accuracy of commercial WPSs may be caused by unreliable or unsecured databases, which contain the essential WiFi-array information to produce local positioning. Knowing this, the quality of WiFi-based positioning services can be enhanced by improving the quality of a database with well-surveyed and accurate information. The Saskatchewan Enhanced positioning System (SaskEPS) is designed to reduce common errors in WPS. SaskEPS's positioning accuracy and consistency is supported by a thoroughly validated Access Point (AP) database. It has been tested in several buildings at the University of Saskatchewan and successfully provides GPS-like positioning accuracy. Our tests have also begun to elucidate the role of WiFi density in ensuring GPS-like positioning accuracy in indoor spaces. In this paper, we investigate the quantitative relationship between WiFi density and SaskEPS's overall positioning accuracy.

Exploring Mobility Indoors: an Application of Sensor‐based and GIS Systems

“…Our contribution in this article corresponds primarily to the methodology itself, and not the insights gained from this methodology already discussed in other works (Petrenko et al. ; Jung and Bell ). This kind of technique permits a new level of precision in the understanding of indoor behavior without the need to deploy new systems either for the space or the individual.…”

“…WiFi is susceptible to environmental influences that affect the precision, performance, and reliability of the technology (Jung and Bell ); the effect that environmental variance has on WiFi is the primary reason there is not a single accurate and reliable positioning system in development today. Many of the existing systems have received limited adoption because they are targeted at consumers as navigation aids (Kourouthanassis and Roussos ).…”

“…The exact locations of APs are stored in a server‐located database. To ensure correct positioning, the system also calibrates the signal strength and assesses whether an AP signal is experiencing interference from structures such as floors or walls (Jung and Bell ). SaskEPS produces 2.5 dimensional positioning information that consists of X, Y coordinates, and floor information.…”

“…Each of the 20 interconnected buildings that are included in the network is represented as a multi‐level structure and they are separated according to their floor number. The WCN was created based on CentreLINE (CL) with the purpose of capturing and simplifying the geometry of building layout, improving positioning, and supporting indoor navigation (Jung and Bell ; Petrenko et al. ).…”

Localization in an Industrial Environment: A Case Study on the Difficulties for Positioning in a Harsh Environment

“…Hence, localizing users or objects in indoor environments for location-based services has become a central topic of research in the last decades (cf. [4][5][6]). Similar to outdoor systems, indoor systems can also be based on time difference of arrival (TDOA).…”