In these days, an interest on location based services (LBS) aroused. This may help first responders in an emergency environment to secure the safety. To achieve this goal, the positioning method with the simultaneous localization and mapping (SLAM) utilizing portable access points (APs) and the extended Kalman filter is developed. In this paper, the position determination method at the entrance of emergency environment for the first responders is presented to provide the absolute position of the first responders. System structure and a simulation result to certify the proposed method would be followed.

Keywords: indoor positioning, seamless positioning, first responders