A Coordinator Loss-Tolerant Zigbee Mesh Network with Region Detection Using RFID for the Real-time Indoor Positioning System

Abstract

in Zigbee network, the coordinator is the most important nodes. If the coordinator lost, this would lead the network into non-controllable state, or even cause the collapse of the entire network. The mesh network, designed for the RIPS(The Real-time Indoor Positioning System) which has about 4000 nodes and used to monitor the baby and other special patients in hospital, contains multiple networks and must have a coordinator in each network. Simultaneously, in the RIPS, the coordinator in each network is used as a gateway. Thus, it is important that there is coordinator loss-tolerant mechanism in each network for improving the reliability of the RIPS. On the other hand, indoor positioning system needs the region detection, but the zigbee mesh network does not distinguish region. Therefore, region (eg room) detection in each network of the RIPS is necessary to prevent false alarms. In this paper, for these problems, a zigbee mesh network with coordinator loss-tolerant mechanism and region detection using RFID is designed and implemented. There is a backup coordinator in each network, first it works as a router and then it adopts the binding mechanism to real-time monitor the working status of coordinator. Similar to the access control system, the region detection uses RFID Detector, which is the Zigbee Router with RFID reader, to monitor the moblie nodes' status of entry and exit. Experiments show that the mechanisms are feasible and effective.