An indoor location system performance evaluation and electromagnetic measurements

Radio signals based indoor location systems is a hot topic. Even many papers deals with this subject, and some solutions were tested, currently we have no mature commercial implementations. Based on WLAN, RFID, WSN, ZigBee or proprietary solutions, location systems working principles implies the measurement of radio signals. Due to propagation issues in real working conditions, the practical demonstrated performances are far enough from theoretical simulation results. In indoor environments, the presence of different objects in rooms may cause multiple propagation paths, dynamic position changing objects or human presence affect the measurement precision. In this paper, we evaluate a 2.4 GHz WSN based location system both in an isolated environment setup - in a shielded room, and in real conditions in a laboratory room and compare the results. We measure the electromagnetic field generated by the system, in order to estimate the potential risks to humans if these systems are massively deployed.