Communication Protocols and Applications for ZigBee-Based Wireless Sensor Networks

ZigBee is a standard which is considered to be suitable for wireless sensor networks (WSNs). This paper discusses four research topics in ZigBee-based WSNs. First, we observe that using the ZigBee network formation scheme may lead to some nodes cannot join the network. We model an orphan problem to characterize this phenomenon. Second, based on the observation that convergecast is a fundamental operation in WSNs. We define a minimum delay beacon scheduling problem for quick convergecast in ZigBee tree-based WSNs. Third, we promote a new concept of long-thin (LT) topology for WSNs, where a network may have a number of linear paths of nodes as backbones connecting to each other. We propose a simple, yet efficient, address assignment scheme for a LT WSN. Finally, we introduce a novel 3D dynamically path finding algorithm based on ZigBee WSNs. This algorithm aims to guide people to safe places when emergencies happen.