Hierarchical Asset Tracking System using IEEE 802.15.4a Radio in Container Terminals

Due to the increase in the volume of international trading, throughput of logistics terminals has emerged as an important issue. It is important to ship and unload container cargo rapidly to improve throughput. The real-time location tracking of various vehicle assets is a major factor for efficient port terminal processing. In this paper, we will describe a system that we designed for asset tracking using IEEE 802.15.4a-based wireless communications for the efficient management of vehicles in the logistics terminals, and we will provide data from performance evaluations obtained from a real terminal environment. We applied a hierarchical-based tracking technique to overcome a non-line of sight (NLOS) problem. We improved the tracking estimation accuracy of yard tractors between container stacks by measuring a transfer crane's precise location using communication between the light tower's readers and crane's mobile readers. We improved the tracking estimation accuracy of yard tractors between container stacks using a transfer crane's precision location. For measuring the crane's precision location, a mobile reader was attached to the crane. The mobile reader communicates with readers attached to light towers so that line of sight (LOS) is guaranteed. The proposed tracking system was installed at Gwangyang International Terminal, where we carried out an asset tracking performance evaluation. The results of the evaluation in a real logistics terminal confirmed that the tracking system has an estimated tracking error of approximately 6.53 m.