电子科大_无线传感器网络_wsnchapter概述

1、1会计学电子科大电子科大_无线传感器网络无线传感器网络_wsnchapter概述概述无线传感器网络涉及这么多知识、技术。需要哪些基础？达到什么目标？需要掌握哪些重点？起源于军事目的的无线传感器网络在民用化过程中会出现哪些问题？对其后续发展带来什么影响？以上哪些特征是“普世化”的，哪些特征只针对特定的应用场景。以上哪些特征是“普世化”的，哪些特征只针对特定的应用场景。从无线联网的从无线联网的角度来看，传角度来看，传感器网络节点感器网络节点的体系由分层的体系由分层的的网络通信协网络通信协议、网络管理议、网络管理平台和应用支平台和应用支撑平台撑平台三个部三个部分。分。物物 理理 层层数据链路层数据链

2、路层网网 络络 层层传传 输输 层层应应 用用 层层能能 量量 分分 配配移移 动动 管管 理理应应 用用 优优 化化网络通信协议类似于传统网络通信协议类似于传统InternetInternet网络中的网络中的TCP/IPTCP/IP协议体系，它由协议体系，它由物理层、数据链路层、网络层、传输层和应用层组成。物理层、数据链路层、网络层、传输层和应用层组成。各层内容将在后续章节依次介绍讨论各层内容将在后续章节依次介绍讨论。Chapter 1:Introduction任务管理中心任务管理中心 Internet、卫星、卫星或移动通信网或移动通信网络等络等汇聚节点汇聚节点监测区域监测区域传感器节点传感

3、器节点Sink传感器节点传感器节点Internet、卫、卫星或移动通星或移动通信网信网WSN体系结构体系结构终端终端用户用户检测区域检测区域2.25 inMicrophoneAccelerometerLightTemperatureSounderMagnetometer1.25 in回顾微机原理或嵌入式系统内容理解无线传感器节点系统平台结构和组成，工作原理及应用无线传感器网络都是以此为基础n Smalln Low powern Low bit raten High density n Low cost (dispensable)n Autonomousn AdaptiveSENSING UNI

4、TPROCESSING UNIT传感器节点的具体产品传感器节点的具体产品25 lb, 19.5 x 5.5 x 16 inch 64 W $6K (today)160 KB Floppies16-256 KB RAM4.77 MHzOriginal IBM PC (1981)0.5 oz, 2.25 x 1.25 x 0.25 inch14 mW $125512 KB Flash128 KB RAM8 MHzMICAZ Mote (2005)Rockwell WINSSmart DustJPL Sensor WebsDustMICA MoteRene MoteweC MoteDot MoteF

5、eatureImote (2003)Mica2 (2003)MicaZ (2004)Telos (2005)Stargate (2005)Imote2 (2009)Speed MHz1288840013-416*Flash kB(Program)5121281284832,00032,000Serial Flash kB(Measurement data)N/A#5125121024N/A#N/A#SRAM / EEPROM / SDRAM kB(Configuration)64441064,000256-32,000 * Multiple processor speed levels# Im

6、ote, Stargate, and Imote2 use a single Flash for program and measurement data Imote, Imote2, and Telos use SRAM; Mica2 and MicaZ use EEPROM; Stargate uses SDRAM Imote2 will have different versions, SRAM changes accordinglyFeatureImote (2003)Mica2 (2003)MicaZ (2004)Telos (2005)ImoteRadio Frequency2.4

7、 GHz300-900MHz2.4 GHz2.4 GHz2.4 GHzDataRate kb/s72015250250250 (720 /11,000 )Power CarrierSense/Rx./Tx. mA15 / 24 / 248 / 10 / 278 / 20 / 181 / 20 / 1840/20/18PowerSleep mA1-250 192761-100 Radio Range32 ft (10 m)500 ft (150m)300 ft (100m)400 ft (125m)100ft (30m)Power sourceAA Battery2xAA2xAA2xAA3xAA

8、A With external Bluetooth adapter With external WLAN adapter Different sleep levelsLogger FlashATMega128L controllerAnalog I/ODigital I/OFreq. Tunable Radio51-Pin Expansion ConnectorAntennaMMCX connectorLEDsRangePeak Data RateCloserFartherSlowerFasterUWBHomeRFWireless Data ApplicationsWireless Video

9、 ApplicationsIrDA802.11g802.11b802.11a2.5G/3GZigBee802.15.4BluetoothISM LinkWiFiCommon NameZigbeeBluetoothWiFiUWBIEEE standard802.15.4802.15.1802.11802.15.3Max Data Rate250Kbps750Kbps54Mbps1000+ MbpsTX power30+ mA40+ mA400+ MaStandby ldd3ua200ua20maStack Size8-60KB100+ KB100+ KBNetwork TypeStar, Clu

10、ster, MeshStar(8 nodes max)StarNetwork Join/FormationmssecondssecondsMax Packet Size(bytes)1323594095RangeOver 1200 meters100 meters100 meters 10 metersDevices2168ZigBeeReduced Function Device (RFD)Limited to being leaf devicesCannot become a network coordinatorTalks only to a network coordinatorVer

11、y simple implementationsimple devices; e.g. Light switch, infrared sensor38 primitivesFull Function Device (FFD)Any topologyNetwork coordinator capableTalks to any other device3 modes: PAN Coordinator, Coordinator, Device49 primitives (14 PHY+ 35 MAC) (1/3 of Bluetooth)Cluster TreeMeshStarPAN Coordi

12、natorFull function deviceReduced function deviceClustered stars - for example,cluster nodes exist between roomsof a hotel and each room has a star network for control.Point to point频段频段 (MHz)扩频参数扩频参数数据参数数据参数片速率片速率 (kchip/s)调制方式调制方式比特速率比特速率 (kb/s)符号速率符号速率 (ksymbol/s)符号符号868868.6300BPSK2020二进制90292860

13、0BPSK4040二进制868868.6*400ASK25012.520-bitSPSS902928*1600ASK250505-bitSPSS868868.6*400O-QPSK1002516-ary正交902928*1000O-QPSK25062.516-ary正交24002483.52000O-QPSK25062.516-ary正交注：* 项为可选项目，系新增内容868MHz / 915MHz PHY868.3 MHzChannel 0Channels 1-10928 MHz902 MHz2 MHz2.4 GHzChannels 11-262.4835 GHz5 MHz2.4 GHz P

14、HY802.11 DSSS2.4122.402.412.482.472.462.452.442.432.422.4622.4372.4835(end of ISM Band)Possible 802.11 Channel(North America)802.11 Spectrum Occupancy (Typical)PHY 负载物理帧头(PHR)同步头(SHR)PSDUReserved(1 比特)Frame length(7 比特)SFD前导码（preamble）可变1 字节1 字节Ocets:4 字节SFD，Start-of-Frame DelimiterPSDU，PHY Service

15、Data Unitl帧头帧头MHR，MAC Header：包括帧控制域，帧序列号，地址和用于加解密的附加安全头部l帧尾帧尾MFR，MAC Footer：16位CRC校验码4 Types of MAC Frames:lBeacon FramelData FramelAcknowledgment FramelMAC Command FrameImpact AnalysisAddressingRoutingSecurityNetwork managementLow power(1-2 years lifetime on batteries)Storage limitations, low overh

16、eadPeriodic sleep aware routing, low overheadSimplicity (CPU usage), low overheadPeriodic sleep aware management, low overheadLow cost($10/unit)Stateless address generationSmall or no routing tablesEase of Use, simple bootstrappingSpace constraintsLow bandwidth (300kbps)Compressed addressesLow routi

17、ng overheadLow packet overheadLow network overheadHigh density(2-4? units/sq ft)Large address space IPv6Scalable and routable to *a node*RobustEasy to use and scalableIP network interactionAddress routable from IP worldSeamless IP routingWork end to end from IP networkCompatible with SNMP, etc25 lb, 19.5 x 5.5 x 16 inch 64 W $6K (today)160 KB Floppies16-256 KB RAM4.77 MHzOriginal IBM PC (1981)0.5 oz, 2.25 x 1.25 x 0.25 inch14 mW $125512 KB Flash128 KB RAM8 MHzMICAZ Mote (2005)Common NameZigbeeBluetoothWiFiUWBIEEE standard802.15.4802.15.1802.11802.15.3Max Data Rate250Kbps750K