An Application Research On A System Of Information Publishing/subscribing And Signal Controlling Based On ZigBee

Wireless sensor network is another hot IT technology after Internet, which will have a significant impact on human's life in 21^st century. If we can say that Internet has changed the style of interactions among human beings, sensor network will change the style of interactions between human beings and nature, with fusing the logic information world and the real human world together in the future. ZigBee is a kind of wireless sensor network promoted by ZigBee Alliance.This thesis researches a system of information publishing/subscribing and signal controlling based on ZigBee technology on the platform of small region intelligent transportation system. The main work that has been finished in this paper contains two parts:Part 1: Researchs and analyzes the stack. Uses and develops the stack. Establishes a software application platform based on ZigBee. (1) Researching and analyzing: Microchip ZigBee stack is a open source stack. And this provides the conditions to study the stack deeping into it. This paper has done a deep research on: source code processes, data structures, important parameters, primitives and functions inside the stack. The paper refers to and looks up to a lot of important Chinese documents and English documents. The scope of this paper's study contain: APS and NWK. (2) Using and developing: All the resources of Microchip ZigBee stack are open and can be used by developers. This paper does a research in details on the resources provided by the stack, and develops a software procedure based on ZigBee stack. (3)Establishing: Referring to the standards of ZigBee Alliance (ZigBee Specification), this paper does some improvements on Microchip ZigBee stack such as address distribution, so that we can use ZigBee stack more standard. On the basis of using the stack sensibly and improvements, the paper establishes a software application platform based on ZigBee.Part 2: designs and develops three types of nodes, designs and develops the hardware of nodes, designs and develops the communication between coordinator node and PC, Connects with small region intelligent transportation system and establishes a system of information publishing/subscribing and signal controlling. The nodes on the electric sand table screen are the work of this paper. There are three types of the nodes: signal controlling nodes, information publishing/subscribing nodes and coordinator node. These three types of nodes are designed and developed on the basis of the software application platform developed by this paper. The hardware of nodes include: PIC18F4620 module, serial communication module, power module and CC2420 RF module.Concerning with the arrangement of this paper , significance of wireless sensor network researches and present situation both home and aboard are introduced firstly. In Chapter 2, the APS and NWK of ZigBee stack are deeply researched and analyzed. Some of important functions of SAPs are also described in this Chapter 2. In Chapter 3, the platform and hardware of the system of information publishing/subscribing and signal controlling are designed. In Chapter 4, the hardwares of nodes are designed and developed, and each circuit module of nodes are detailly described. In Chapter 5, the software of nodes is designed and developed. The design of endpoint inside the node, software of coordinator node, software of signal controlling nodes, software information publishing/subscribing nodes, how to use ZigBee stack in node software are introduced in details. Finally, this paper introduces two sub-systems: signal controlling sub-system and information publishing/subscribing sub-system. In Chapter 6, communicating agreement stack and frame format between PC and coordinator node are designed and developed. At last, Chapter 7 is a conclusion with the summary of the thesis and prospect research.