Tag-to-Tag Mesh Network Using Dual-Radio RFID System for Port Logistics

Abstract

This paper consists of two parts: the protocol for tag-to-tag mesh network (T2T-MN) and the implementation of dual-radio RFID system. Recently, RFID has been adopted in ports or warehouse, being attached to containers and palettes for loading/unloading automation. However, the RFID system has encountered one problem—some tags cannot receive any command from reader intermittently due to signal interference by containers or field equipments (e.g., cranes and yard tractors). This area where reader signal cannot reach is called dead-zone. This paper resolves the dead-zone problem by enhancing the RFID network to support the multi-hop communication between tags. Meanwhile, the multi-hop communication increases the number of transmission of tags, resulting in the high collision probability. Thus, the dual-radio RFID system is adopted in this paper, which utilizes two different radio frequencies for tag-to-reader communication and tag-to-tag communication. The experiment shows that the proposed multi-hop RFID network can resolve the dead-zone problem.