Multi-subnetwork Switching Mechanism in the Large-Scale Zigbee Mesh Network for the Real-Time Indoor Positioning System

with the advantages of lower energy consumption, lower cost and higher reliability, the Zigbee technology is applied widely in positioning system. In our real-time indoor positioning system (RIPS), there are almost 4000 nodes in a building. In such a large-scale network, when hundreds of nodes send data to coordinator, the coordinator takes heavy load which causes serious packet loss and weak network performance. This paper realizes a multi-sub network switching mechanism for real-time indoor positioning system (RIPS) to solve the heavy load of coordinator. In the RIPS, we deploy multiple sub networks in the building, using the technology of Zigbee and RFID to achieve switching between multiple sub networks automatically. To realize the function of switching between different sub networks, we define proper frame format to regulate the communication way. What´s more, the existing CC2530 hardware is based on the two-dimensional coordinate, it can´t identify which floor the blind node locates on, in this paper, a three-dimensional coordinate method is raised. We can read the z-coordinate to specify the position of blind nodes.