METHOD AND SYSTEM FOR TRACING POSITION OF MOBILE DEVICE IN REAL TIME

摘要

The present invention relates to a technique for reducing computing power and improving accuracy when tracing the position of a terminal in real time based on strength of a wireless signal in a wireless LAN environment. The invention can be achieved by comprising: a first step for selecting a calibration point, receiving from the access point the strengths of a certain number of wireless signals for every calibration point, and generating or interpolating the data necessary for position estimation such as an average value and standard deviation of the strengths of the wireless signals based on the results from the reception; a second step for receiving the strength of a wireless signal from a client in real time, accumulating position history depending on the strength of the wireless signal, obtaining a certain number of previous positions using the position history, then calculating an anticipated position of the client based on the previous positions, average speed vector, and time; a third step for designating candidate calibration points based on the previous positions, obtaining a Bayesian probability to calculate the probability that the strengths of the wireless signals received from the client appear in each candidate calibration point, and obtaining an estimated position of the client based on the probability, wherein a weight depending on the distance between the anticipated position and each candidate calibration point is applied to Bayesian probability; and a fourth step for comparing a zone threshold value with the distance difference between the anticipated position and the estimated position, and deciding whether or not the estimated position resulting from the comparison is considered as the estimated position.