WLAN and Bluetooth Positioning in Smart Phones

Abstract

Although the short range radio frequency technologies such as WLAN (Wireless Local Area Network) and Bluetooth were originally designed for the purpose of wireless communication, they have been widely adopted as common signals of opportunity for positioning in smart phones for both indoors and outdoors. The cell identifier and radio signal strength are the most common observables used for positioning. The applicable position methods include Cell-ID, fingerprinting, and trilateration. Fingerprinting is the most common approach, which can provide a positioning accuracy of even 2-5 meters indoors using either the pattern recognition algorithm or the probabilistic algorithm; however, the obtainable accuracy depends on the positioning environment. The objective of this chapter is to present the WLAN and Bluetooth positioning methodologies and explain the related positioning algorithms. The chapter covers an introduction of the topic, descriptions of the observables, the positioning algorithms, and the implementation issues of the positioning solutions. The chapter is concluded with a short section of future research directions followed by a brief conclusion.