【作者】 易安安；

【导师】 刘希顺；

【作者基本信息】 国防科学技术大学 ， 电子与通信工程， 2009， 硕士

【摘要】 无线传感器网络(Wireless Sensor Network,WSN)综合了微电子技术、嵌入式计算技术、现代网络及无线通信技术、分布式信息处理技术等先进技术,能够协同地实时监测、感知和采集网络覆盖区域中各种环境或监测对象的信息,并对其进行处理,处理后的信息通过无线方式发送,并以自组多跳的网络方式传送给观察者。传感器网络的应用前景十分广阔,在军事、工农业、环境监测,医疗护理、抢险救灾、危险区域远程控制以及智能家居等领域都有潜在的使用价值,已经引起了许多国家学术界和工业界的高度重视。802.15.4/ZigBee是一个由ZigBee联盟定义的低速率、低功耗的无线个域网通信标准,802.15.4/ZigBee是目前在无线传感网络中应用最为广泛的协议体系,无线传感网络的特性决定了其无线应用不需要较高的传输带宽,而需要较低的传输延时和极低的功率消耗,低成本、低功耗、应用简单的IEEE 802.15.4/ZigBee协议的诞生为无线传感器网络及大量基于微控制的应用提供了互联互通的国际标准。本文基于802.15.4/ZigBee,为无线传感网络在智能楼宇监测系统中的应用研究设计了一个结合时分复用和多信道调度(频分复用)的动态按需MAC机制-ZTF-MAC,并分别针对星型和簇树结构网络拓扑进行了详细研究和讨论。在星型结构网络中,按需对节点进行分组并对各组进行时隙调度。在簇树结构网络中,除按需性的分组机制外,加入了多信道的调度,为子网分配和使用多信道机制,这种按需性的分组和动态的多信道调度,可减少由网络节点密度大所造成的冲突和干扰,增加网络吞吐量。此外,为了适应网络中的实时性紧急事件的数据传输要求,ZTF-MAC中特别考虑和设计了对紧急事务的响应机制,这样,在保证网络整体吞吐量的同时,还可获得对紧急事务的快速响应。本文通过仿真分析了ZTF-MAC的吞吐量、能耗和紧急事务响应时延三个方面的性能。仿真结果表明ZTF-MAC可改善802.15.4的吞吐量和能耗性能,同时具有对网络应用紧急事务快速响应的特性。服务原语和命令帧的设计是通信标准协议栈设计的原型和参考规范,本文最后研究和分析了802.15.4/ZigBee协议规范中的服务原语和命令帧,并为ZTF-MAC设计实现了相关的原语和命令帧。更多还原

【Abstract】 Wireless Sensor Network (WSN) combines some advanced technologies such as microelectronics, embedded computing, modern network, wireless communication and distributed information processing. It can real-timely monitor and collect various environmental information data that are processed and then sent through wireless communication. The transmission is in multi-hop and Ad hoc mode. WSN has broad application prospect. It can be applied to military affairs, industry, agriculture, environment monitoring, health care, emergency and disaster relief, remote control, smart home, et al. WSN has been highly emphasized by academic circles and industrial community in many countries.802.15.4/ZigBee is a low rate, low energy consumption Wireless Pan Area Network (WPAN) protocol defined by ZigBee Alliance. At present, 802.15.4/ZigBee is the most widely protocol architecture used in WSN. Characteristics of WSN determine that its wireless applications do not need high transfer bandwidth, but low latency and energy consumption. IEEE 802.15.4/ZigBee provides international communication standard to WSN and vast applications based on Micro Control Unit (MCU。Based on 802.15.4/ZigBee, this paper researches and designs a dynamic and on-demand MAC scheme called ZTF-MAC for application of Smart Building in WSN. ZTF-MAC combines Time Division Multiple Access and multi-channel scheduling. ZTF-MAC is discussed in detail for Star and Cluster-tree topology network respectively. In Star network, nodes are on-demand grouped and scheduled by time slots. In Cluster-tree network, in addition to grouping scheme, multi-channel scheduling is added for subnet. The on-demand grouping and dynamic multi-channel scheduling can reduce collision and interference induced by high node density, then increase network throughput. Furthermore, there are some real-time emergent data to transmit in WSN, and ZTF-MAC specially concerns and designs respond scheme for emergent events. In this way, ZTF-MAC can quickly responds for emergency with high throughput in the whole network.Throughput, energy Consumption and latency in response of emergency in ZTF-MAC is simulated. The results indicate that ZTF-MAC can improve performance of them in 802.15.4. At the same time, ZTF-MAC can quickly response for emergency in WSN. Service primitive and command frame are prototypes and reference specifications for design of protocol stack. At last, this paper studies and analyzes primitives and command frames in 802.15.4/ZigBee, and realizes relevant primitives and command frames of ZTF-MAC.更多还原