1、2022/11/211一個傳感器網絡調查Ian F.Akyildiz,Weilian Su,Yogesh Sankarasubramaniam,and Erdal CayirciGeorgia Institute of TechnologyReport：yan yi li From:IEEE Communications Magazine August 2002.2022/11/212大綱o Introductiono 感測網路的通訊體系架構n Physical,Data link,Network,Transport,Applicationo 結論2022/11/213Introduction
2、o Application areas:nHealth,military,home,and commercialo The differences between sensor networks and ad hoc networks:nThe number of sensor nodes in a sensor network can be several orders of magnitude higher than the nodes in an ad hoc network.nDensity of deploymentnProbability of failurenChange of
3、topologynHardware constraint2022/11/214感測網路的通訊架構感測器節點通常分散於感測領域這些分散的每一個感測器節點都有能力去收集數據資料並且回傳路由數據到接收端.接收端可以通過網路或是衛星和事件管理者做通訊.2022/11/215感測網路設計的影響因素o including fault toleranceo Scalabilityo production costso operating environmento sensor network topologyo hardware constraintso transmission mediao power
4、consumption2022/11/216硬體的限制2022/11/217感測網路通訊架構Used by the sink and sensor nodes 2022/11/218實體層o 頻率選擇，載波頻率的產生，信號檢測，調變以及數據加密 o 915 MHz ISM頻帶已被廣泛提出的感測網路nIndustrial,scientific,medicalo 追求的能量使用效率n二進制和多進制調變n(超寬頻)UWB 無線電脈衝(IR)o 基頻o 不需要媒介或者是載波頻率o 脈衝位置調變(PPM)o 較低的傳輸電力和簡單的收發器2022/11/219實體層o Open research issu
5、es:n Modulation schemeso Simple and low-powern Strategies to overcome signal propagation effectsn Hardware designo Tiny,low-power,low-costo transceiver,sensing,and processing unitso need to be designed.2022/11/2110資料鏈結層o Responsibility:n Multiplexing of data streamsn Data frame detectionn Medium acc
6、ess controln Error control2022/11/2111資料鏈結層o Open research issues:n MAC for mobile sensor networkso SMACS and EARn Determination of lower bounds on the energy required for sensor network self-organizationn Error control coding schemesn Power-saving modes of operationo Turn the transceiver off when i
7、dleo Using short data packets2022/11/2112網路層oDesigned according to the following principles:n Power efficiencyn Data-centricn No hinder the collaborative effortn An ideal sensor network has attribute-based addressing and location awareness2022/11/2113網路層o Route 1:Sink-A-B-T,total PA=4,total=3o Route
8、 2:Sink-A-B-C-T,total PA=6,total=6o Route 3:Sink-D-T,total PA=3,total=4o Route 4:Sink-E-F-T,total PA=5,total=6o Maximum PA route:nRoute 4o Minimum energy(ME)route:nRoute 1o Minimum hop(MH)route:nRoute 3Route 1:Sink-A-B-T,total PA=4,total=3,Route 2:Sink-A-B-C-T,total PA=6,total=6,Route 3:Sink-D-T,tot
9、al PA=3,total=4,Route 4:Sink-E-F-T,total PA=5,total=62022/11/2114網路層o Floodingo Gossipingo Sensor protocols for information via negotiation(SPIN)o Directed diffusionADVREQDATAADVREQDATASourceSinkStep 1:propagate interestStep 2:set up gradientStep 3:send data2022/11/2115網路層o Open research issuesn Imp
10、roved or new protocols to address higher topology changes and higher scalability.2022/11/2116傳輸層o Need when system is planned to be accessed through the Internet or other external networkso Between sensor node and sink node:UDPo Between sink node and user:UDP or TCPTCP/UDP?2022/11/2117傳輸層o Open rese
11、arch issuesn Hardware constraints such as limited power and memory.Each sensor node cannot store large amounts of data like a server in the internet.n may be needed where UDP-type protocols are used in the sensor network and TCP/UDP protocols in the internet or satellite network.2022/11/2118應用層o Pot
12、ential application layer protocols for sensor networks remains a largely unexplored region.o three possible application layer protocolsn Sensor management protocol(SMP)n task assignment and data advertisement protocol(TADAP),n Sensor query and data dissemination protocol(SQDDP)2022/11/2119應用層o Open
13、research issuesn Although SQTL is proposed,other application layer protocols still need to be developed to pride a greater level of servicesn Research developments should also focus on TADAP and SQDDP2022/11/2120Conclusiono Wide range of application areaso New sensor networking techniques are requiredo Intend to motivate a search for solutions to the open research issues
