Location-based Services Fundamentals and Operation

Chapter 9. Indoor Positioning

Traditionally, LBSs were designed for supporting typical outdoor applications, for example, fleet management and navigation. However, the potentials of location-related indoor applications were realized much earlier as LBSs entered the market. They were explored in conjunction with research on ubiquitous computing since the beginning of the 1990s. Typical application fields that were and still are under investigation address office environments and shopping malls, to name only a few. Though research and development considered outdoor and indoor LBSs strictly separated from each other for a long time, there is now an increasing demand for an integrated approach. From the users' point of view, it would be very convenient to invoke indoor and outdoor LBSs by using the same mobile devices, while service providers might be interested in reusing their infrastructures, interfaces, and protocols for both types of LBSs.

However, the major problem of an integrated approach is the absence of a common, universal positioning technology. Conventional GPS receivers do not work inside buildings, while cellular positioning methods generally fail to provide a satisfactory degree of accuracy. The delivered position fixes cannot even be used for determining whether a target person stays inside or outside a certain building, not to mention that it is by no means possible to locate it with the granularity of rooms or floors. Thus, there is a demand for stand-alone indoor ...