Analysis of the Optimal Strategy for Wlan Location Determination Systems

This paper presents a general analysis for the performance of WLAN location determination systems. WLAN locations determination systems estimates the user location using software-based techniques in a WLAN environment. We present an analytical method for calculating the average distance error and probability of error of WLAN location determination systems. These expressions are obtained with no assumptions regarding the distribution of signal strength or the probability of the user being at a specific location, which is usually taken to be a uniform distribution over all the possible locations in current WLAN location determination systems. We use these expressions to find the optimal strategy to estimate the user location and to prove formally that probabilistic techniques give more accuracy than deterministic techniques, which has been taken for granted without proof for a long time. The analytical results are validated through simulation experiments and we present the results of testing actual WLAN location determination systems in an experimental testbed. We also study the effect of the assumption that the user position follows a uniform distribution over the set of possible locations on the accuracy ∗Also affiliated with Alexandria University, Egypt.