The location-sensing technology is a core technology of location-based services and applications. In this paper, we present a location-sensing method, called as cell-based positioning method and its positioning accuracy estimation. In addition, we apply simulated annealing (SA) method to determine the locations and transmission ranges of base stations such that a better positioning accuracy is achieved. The numerical experiments are also given to show that the proposed method is effectiveness. KEY WORDS Location-sensing, location determination, location-based applications.