ZITAG: ZigBee Identification Tag Framework for Warehouse Chin-Song Lim, W.A.F.W.Othman, M.R.Arshad School of Electrical & Electronic Engineering Universiti Sains Malaysia Engineering Campus Penang, Malaysia Email: lcs10 eee105@student.usm.my, eeamirfuad@eng.usm.my, rizal@eng.usm.my Abstract—Real-time inventory location sensing tracking fea- ture demand has become an increasing trend in warehouse system. Conventional manual or computerized rack indexing, storing and retrieving process has meet limitation in view of fast turnaround inventory transaction business environment. In this paper, we proposed the ZigBee Identification Tag (ZITAG) and its design framework, which is combination of tag function and ZigBee wireless sensor node. ZITAG is embedded with read- writable unique identifier and provides real-time indoor location reference data when activated. ZITAG, Auto ID, RFID, ZIGBEE, location sensing, RSSI. I. I NTRODUCTION The blooming smart phone and tablet economy worldwide has drive semiconductor industry to progress more rapidly than before. As consequences, timing has become the criti- cal factor for electronics devices manufacturers and logistics service provider. Thus, more advanced, accurate and real-time inventory position tracking methodology is highly required in enhancing the current warehouse system. This motivates the idea of ZigBee Identification Tag (ZITAG) framework which purpose is to simplify the inventory placing procedure and pro- vide effective and target-oriented inventory retrieving process. Without additional sensor interface, ZITAG is able integrated with event-triggering mechanism for expiring inventory which required to be handle or transit, preventing items from being un-found, and can be incorporated with anti-theft mechanism. The content of this paper is organized as follow: Section II described the background and related technology. Section III explains the methodology. Section IV illustrated the ZITAG framework, architecture and proposed prototype model. Pre- liminary experiment result is presented in Section V. Section VI summarized the framework and future works. II. BACKGROUND A. Current Challenges Barcode and Radio Frequency Identification (RFID) are among two widely used technologies in inventory tracking system. Using RFID tag has better advantages over barcode label, but still has some drawback in some situation. When component is placing at metal rack, RFID tag reader may reduce it reading efficiency due to RF signal reflection. Al- though passive type RFID anti-metal tag is available but the tag is expensive due to it special made and unable to tell the distance between tag and reader, posing the challenge to locate the object position precisely. Handheld RFID reader has limitation of reading distance of 1-2m practically. A warehouse rack might span over 3-4 floor or 20m height, which is out of reading range of handheld reader. Although static RFID reader can be installed at the multiple points of the warehouse, it is unable to tell which level the container or carton is located, its cost is expensive and large quantity of reader is required to install. Commercially available static mounted RFID reader reading range is 5m and 10m. Due to the competitive business environment, warehouse owner also provide rack space rental facility to different customer to store their inventory, so called shared-service warehouse. This business feature has added another level of complexities to the situation. The same company personal who has authority to enter the warehouse might just transfer the inventory from one storage location to another location (both belonging to their own company rented space) in the warehouse, and their might tend to forget where is the rack due to human habits of negligence. Finally, time to retrieve the inventory by another personal who request for the inventory will be consuming. B. Related Works Over the past few years, tremendous interest and research effort has been worked on Real-time Location System. As a result, many of sensor network technology have been suc- cessfully applied to remote control and monitoring application [11]. Wireless network sensor platform, measurement metric and localization algorithm are major factors that required continuous enhancement in order to build a mature platform for warehouse inventory real-time tracking system. The 802.11 WLAN / WIFI [10], [21] and IEEE 802.15.4 / ZigBee [20], [5], [12], [6] were among the popular wireless standard used. ZigBee is more suitable over WIFI of small MCU and memory footprint, small network ZigBee header protocol, and battery operated. Wireless sensor network localization measurement metric typically based on Received Signal Strength (RSS), Time of Arrival (TOA), Time Difference on Arrival (TDOA), Angle of Arrival (AOA) [17], [12], [16], [2], [15] and Link Quality 2012 IEEE International Conference on Control System, Computing and Engineering, 23 - 25 Nov. 2012, Penang, Malaysia 978-1-4673-3143-2/12/$31.00 ©2012 IEEE 89