1,Wireless Sensor Networks,巨型机说：“我认为全球大概只需要五台计算机就够了”； PC机说：“每个家庭的桌面上都应该有一台电脑”; Pocket PC说：“太大了，应该每人口袋里放一台”; WSN说：“每粒沙子都应该是一台计算机”。,2,Outline,General Comments Wireless Sensor Network Applications Architecture of WSN Overview of Sensor Hardware Characteristic of WSN Our Work,3,Outline,General Comments Wireless Sensor Network Applications Architecture of WSN Overview of Sensor Hardware Characteristic of WSN Hot Issues Our Work,4,Sensor network: A new research hotspot,August 2003 Business Week projects “Sensors and Sensor Networks“. to be one of 4 Key Technology Waves of the Future,国家中长期科学和技术发展规划纲要将传感器网络列为重点研究领域,5,Faster, Smaller, Numerous,Moores Law “Stuff” (transistors, etc) doubling every 1-2 years,Bells Law New computing class every 10 years,year,log (people per computer),Source: The Mote Revolution: Low Power Wireless Sensor Network Devices,Streaming Data to/from the Physical World,6,Whats are Wireless Sensor Networks,Wireless networks are usually composed of small, low-cost devices that communicate wirelessly and have the capabilities of Processing, Sensing and Storing The purpose is to measure different physical parameters in a given environment, in order to characterize its properties, or to take decisions depending on these measurements.,7,Enabling Technologies,Embedded,Networked,Sensing,Control system w/ Small form factor Untethered nodes,Exploit collaborative Sensing, action,Tightly coupled to physical world,Embed numerous distributed devices to monitor and interact with physical world,Network devices to coordinate and perform higher-level tasks,Exploit spatially and temporally dense, in situ, sensing and actuation,8,Outline,General Comments Wireless Sensor Network Applications Architecture of WSN Overview of Sensor Hardware Characteristic of WSN Hot Issues OUR WORK,9,Wireless Sensor Network Applications,Military Applications Environmental Applications Health Applications Home Applications Industrial Applications Other Commercial Applications,Application WSN,10,Military Applications,enemy tracking, battlefield surveillance target detection and classification,11,An Example:Counter Sniper System,Using the arrival times of the acoustic events at different sensor locations, the shooter position can be accurately calculated using the speed of sound and the location of the sensors.,12,民用领域,土壤湿度、温度、成 份监测，节点对土壤 进行周期性采样将数 据发送给远端用户,森林防火：节点实时 监测周围温度情况， 并在探测到温度过高 时发出警报。,医疗看护：将传感器 配置在身体上，可以 将身体情况传输给远 端监控中心。GE公司,13,科技领域,了 解 火 山 习 性,研 究 鸟 类 习 性,海洋环境监测,sensors and vehicles are deployed to perform collaborative monitoring tasks over a given area under ocean. Large number of sensor nodes collect data from the ocean and forward to a master node.,14,Industrial Applications,地面上的 传感节点,立柱上的 传感节点,无线传感网络原型系统拓扑图: 矿井安全检测和防护系统,From talk of Yunhao Luo,15,Outline,General Comments Wireless Sensor Network Applications Architecture of WSN Overview of Sensor Hardware Characteristic of WSN Hot Issues OUR WORK,16,Architecture of WSN,Sensor nodes are scattered in a sensor field(object field) Sensor nodes can self organize to form a sensor network Data are collected by these scattered nodes and routed back to the sink in a multi-hop way The user communicate with the sink via Internet,17,Architecture of WSN(contd),nodes are still stationary. multiple, mobile sinks defined as users. sinks may collect data at any time, any place.,18,无线传感网络,接入网络,核心网络,Architecture of WSN(contd),From Talk of YunHao Luo,19,A general work process of WSN,Deploy,Organize into network,Sensing and monitoring,Data collection and dissemination,20,Outline,General Comments Wireless Sensor Network Applications Architecture of WSN Overview of Sensor Hardware Characteristic of WSN Hot Issues OUR WORK,21,Sensor Hardware,Fundamental Components Various Sensing,Processing,Storing, Transceiver,Power Application dependent components Locating, Mobilizer, Power generator,22,Sensor Node Samples,LWIM III UCLA, 1996 Geophone, RFM radio, PIC, star network,AWAIRS I UCLA/RSC 1998 Geophone, DS/SS Radio, strongARM, Multi-hop networks,Sensor Mote UCB, 2000 RFM radio, Atmel,Medusa, MK-2 UCLA NESL 2002,23,Mote Evolution,Source: The Mote Revolution: Low Power Wireless Sensor Network Devices,24,Outline,General Comments Wireless Sensor Network Applications Architecture of WSN Overview of Sensor Hardware Characteristic of WSN Hot Issues OUR WORK,25,Characteristic of WSN,Resource Constraints battery equipped,recharging the batteries is impossible or unfeasible Radio and embedded CPU Self configuring Randomly deployed, unattended. Dynamic Topology Data centric Different from traditional network Unique traffic model Application specific,26,Power Consumption,Power is of most important and directly influencing the lifetime of WSN Consumption in three domains: Sensing, communication and data processing Energy consumed by Comm. is dominating The energy cost of transmitting 1Kb a distance of 100 m is approximately the same as that for executing 3 million instruct