Database Correlation for GSM Location in Outdoor & Indoor Environments

Estimation of the location of a Mobile Station accurately is a key requirement to effectively provide a wide range of Location Based Services over mobile networks. Hence developing cellular positioning techniques has been a key research problem, with numerous localization solutions been proposed. These include technologies such as Cell ID, angle and time of arrival methods, statistical methods and fingerprinting methods. This paper presents fingerprinting based positioning techniques suitable for outdoor and indoor positioning. Multiple positioning techniques were proposed, implemented and evaluated with outdoor and indoor trials. The ultimate solution proposed in this paper is not a single positioning technique; rather it presents several positioning techniques that achieve optimum performance in each test environment. The results reports 67% positioning error as 112 m, 299 m and 221 m for urban, suburban and rural areas respectively. Experimental results show that the proposed positioning methods achieve accuracy far better than Cell-ID and trilateration approaches for the tested network environments especially for rural areas. The 67% positioning error for rural area is 1045 m and 1386 m with basic Cell-ID and trilateration techniques while proposed fingerprinting based technique reports 67% positioning error as 221m. With indoor positioning this paper reports 50% positioning error as 8.7 m and also it was possible to accurately differentiate between floors in the selected multi storey building. Keywords— Outdoor Positioning, Indoor Positioning, Database Correlation