Design and Implementation of a Real Time Locating Systems over IEEE 802.15.4a Radio for Port Logistics

Real time locating systems (RTLS) are required to provide high quality service for port logistics. When such locating systems are applied to port logistics, however, they encounter the problem of unreachable signals. The environments of port logistics have radio-shaded areas (RSA), which often cause failures in measurement or positioning errors. This paper addresses the design and implementation of a real time locating system over IEEE 802.15.4a radio for application to port logistics. The proposed RTLS include methods that employ assistant tags and a directional-antenna-based reader. In addition, this paper describes experiments and records their performance in order to solve the problem associated with RSAs in the port logistics environment. The results show that the measurement success rate is increased by up to 38%, with a locating accuracy that has a circular error probability (CEP) of 1.13 m.