ZUL - A light-weight architecture for Zigbee-based ubiquitous applications

The IEEE 802.15.4 and the Zigbee wireless protocol are increasingly being used in ubiquitous applications ranging from smart homes to novel learning applications. A common architecture for such applications has emerged. This paper describes a light-weight software architecture for building such applications. The ZUL (Zigbee-Based Ubiquitous Layer) architecture defines two virtual machines; one for the host called ZUL-H and one for the Zigbee nodes called ZUL-E. A reference implementation for the ZUL-H has been developed using the .NET framework while ZUL-E has been implemented using C language for two different types of Zigbee hardware platforms. A case study that re-implements the Prête-à-apprendre+ wearable ubiquitous learning toolkit using ZUL shows that using ZUL makes the design cleaner and easier to maintain.