A Survey of Indoor Positioning Systems and Algorithms Klaithem Al Nuaimi Faculty of Information Technology (FIT) United Arab Emirates University Al Ain, UAE klaithem.nuaimi@uaeu.ac.ae Hesham Kamel Faculty of Information Technology (FIT) United Arab Emirates University Al Ain, UAE hesham@uaeu.ac.ae Abstract—Positioning objects has been an important topic since it is needed to locate people, guide them to a certain place, and assist companies and organizations with their assets management. Several systems and algorithms were proposed to solve the positioning problem and to enhance existing systems. In this paper, we survey various indoor positioning systems to explore the related challenges that exist in this area and evaluate some proposed solutions. We provide a categorization and classification of the current indoor positioning systems and identify some possible areas of enhancements Index Terms—Indoor Positioning, Sensor Networks, Positioning Algorithms, Wireless Positioning Technologies, Object Tracking. I. INTRODUCTION Tracking people and objects became a very interesting field of research in the last ten years. The theory of positioning has been used in various application areas. For example, a company could acquire the necessity to position its equipment to track down its assets. Additionally, indoor positioning is very useful for positioning people within buildings such as hospitals and nursing homes (e.g., positioning the first responders of a rescue team in a building, given the absent of a positioning system). These applications require positioning, either to track down people or to guide them to a certain place within a building in order to save their lives. In an outdoor environment, the Global Positioning System (GPS) works efficiently in positioning and targeting different types of entities. It has been used in many outdoor applications for localizing people, cars, as well as other objects. However, GPS lacks the same level of efficiency when used within indoor environments. This problem is due to the existence of obstacles that can weaken the signal of the GPS (e.g., building architecture, walls) where the existence of different equipment can cause a noise in the GPS transmitted signal. Pedersen [1] proposed a micro positioning strategy that should be implemented within the indoor environment in order to position and track objects. He stated that this strategy would work as a replacement for the GPS positioning system. In addition, Fhelelboom [2] found that a wireless local area network (WLAN) can be used within any indoor environment to position objects. In this paper, we review the different positioning environments, the different systems applied for each environment and the algorithms used within each system. We specify two scenarios for positioning people and objects within an indoor environment. Each of these scenarios has its own challenges, which researchers tried in the past to mitigate by proposing several solutions over the last ten years. We have organized the paper as follows. In the next section, section II, we point out some preliminary technical information regarding indoor positioning. In section III we discuss the problems and challenges that are associated with indoor positioning systems. Next, in section IV we discuss the existing approaches for localizing object within an indoor environment. This is followed by a comparison of the different positioning approaches and solutions in section V. Then, we propose some solutions that can help improve positioning in indoor environment in section VI. Finally, in section VII we render our conclusion. II. PRELIMINARIES Here we present some preliminary information that researchers must be aware of indoor positioning systems and environments. A. Type of Positioning In this section, we focus on two types of positioning. The first type is positioning objects when there is an installed positioning system within the building and users are carrying tools such as RFID or any other equipment based on the wireless sensor network used in the system. We identify this type as a Fixed Indoor Positioning System. The second type is positioning users who have the equipment such as RFID when the building does not have the system installed within that giving environment. It is referenced as pedestrians positioning. B. Positioning Principle There are mainly four principles used in building positioning systems. These principles are Trilateration, Triangulation, Scene Analysis and Proximity [3]. The principle used can provide a faster calculation of the position. It can also provide a better accuracy depending on the system architecture too. 2011 International Conference on Innovations in Information Technology 978-1-4577-0314-0/11/$26.00 ©2011 IEEE 185