User tracking as an alternative positioning technique for LBS

Different approaches are used for positioning of mobile users and all of them have advantages and disadvantages. The Global Positioning System (GPS) offers the easiest and most accurate 3D positioning of the user but it is not operational indoors. The positioning within mobile networks (using only the information related to the base network transmitter) could be made available everywhere but it is rather inaccurate. Still, there are many situations when the position of the mobile client cannot be detected with the needed accuracy and within an acceptable waiting time. This paper investigates a user tracking (more specifically optical tracking) as an alternative approach for establishing locations. The tracking system utilised within the outdoor AR reality system (i.e. UbiCom project) is discussed and new ideas for users tracking for LBS are presented. The ideas are motivated by and linked to the OpenGIS Consortium (OGC) specifications for Location Services and related OGC specifications for Web Services.