Wlan-based Asset Tracking for Warehouse Management

Asset tracking offers high potential to improve efficiency of warehouse management. Typically the tracking is done employing RFID technology. As yet however, most goods are not prepared with RFID and it would require investment in costly hardware, infrastructure, and process adaptations. WLAN-based asset tracking is getting ready as a cost-effective alternative since software-only approaches are becoming mature. They can reuse existing standard WLAN devices and infrastructure for position sensing. In this paper we present such a system – MagicMap – that we have developed for realtime positioning based on WLAN signal strength measurements, and describe how it seamlessly integrates into a warehouse management scenario. Unfortunately, metal construction of a warehouse and high dynamics of goods influence the WLAN signal dissemination and thus make the approach generally difficult for such scenarios. To assess its applicability, we have measured positioning accuracy and real-time capabilities of MagicMap in comparison with two similar systems (Ekahau and MobileLocator Light) in a typical warehouse setup. Result show applicability of all three WLAN-based systems at an average positioning deviation of 3-5 meters and a tracking delay below 150 seconds – provided some physical constrains are considered.