I. Introduction
The aim of Location-based Services (LBS) is to deliver relevant and timely services based on the location of a user [1]. The potential user base for LBS is growing rapidly, since the majority of new mobile devices are today embedded with several sensors used for determining the location and the orientation of a user. The development of mobile devices have also enabled introduction of Mobile Augmented Reality (MAR) applications that can be treated as a special case of LBS [1]. In MAR applications, the data from embedded sensors is used collaboratively for augmenting the view of the physical real world with location-based information [2].