Presentation on theme: "Wireless Sensor Networks"— Presentation transcript:
1 Wireless Sensor Networks Rob Roosendaal, LecturerINHolland University
2 Agenda Introduction Theoretical Background Practical Information AgendaIntroductionTheoretical BackgroundPractical InformationWrap up and questions
3 Introduction to Wireless Sensor Networks Introduction to Wireless Sensor Networks
4 Our projects Alzheimer's disease ADL: Activities in Daily Life Our projectsAlzheimer's diseaseADL: Activities in Daily LifeAcceptance of technologiesHow to measure progress in ADLTablet as interface for easy acceptanceSensor technology for detectionSensor communicationCollecting data
5 Crawling the web Alzheimer's disease Human computer interaction Crawling the webAlzheimer's diseaseHuman computer interactionProgramming Android tabletsConnectiong devices to a tabletWireless Sensor Networks
6 Alzheimer's disease Memory loss that disrupts daily life Alzheimer's diseaseMemory loss that disrupts daily lifeChallenges in planning or solving problemsDifficulty completing familiar tasks at home to work or at leisureConfusion with time or placeTrouble understanding visual images and special relationshipsNew problems with words in speaking or writingMisplacing things and loosing the ability to retrace stepsDecreased and poor judgementWithdrawl from work or social activitiesChange in mood and peronality
7 Framework for Disseminating Data Framework for Disseminating DataEstablish communications message (What should be said?)Define the audience (To whom should it be said?)Select the channel (Through what communication medium?)Market the message (How should the message be stated?)Evaluate the impact (What effect did the message create?)Principles and Practice of Public Health Surveillance (Teutsch and Churchill, 2000)
8 Wireless Sensor Network Wireless Sensor NetworkA wireless sensor network (WSN) of spatially distributed autonomous sensors to monitor physical or environmental conditions and to cooperatively pass their data through the network to a main location. The more modern networks are bi-directional, also enabling control of sensor activity.
9 Measuring physical parameters Measuring physical parametersAcoustic, sound, vibrationAutomotive, transportationChemicalElectric current, electric potential, magnetic, radioEnvironment, weather, moisture, humidityFlow, fluid velocityIonizing radiation, subatomic particlesNavigation instrumentsPosition, angle, displacement, distance, speed, accelerationOptical, light, imaging, photonPressureForce, density, levelThermal, heat, temperatureProximity, presenceSensor technologyOther sensors and sensor related properties and conceptsThis is only a summarized list, the complete list of sensors you can use is about 400 items long !
10 Measuring physical parameters Measuring physical parametersFocusing on healthcare, domotics and personal environmentWhich sensors do we have?
11 IT Points of interest Autonomous sensors Points of interestITAutonomous sensorsPhysical or environmental conditionsCooperatively pass their dataThrough the network to a main location(Bi-directional, control of sensor activity)
13 Physical or environmental conditions Physical or environmental conditions
14 Cooperatively pass their data Cooperatively pass their dataReceive or transmitTransmit if data has to be sentSingle-hopClose byLower transmission rateMulti-hopHigher transmission rateLess nodes availableData-gathering wireless sensor networks: organization and capacity,Enrique J. Duarte-Melo, Mingyan Liu
15 Through the network to a main location Through the network to a main locationWireless and wired network partsDistributed routing, different routing protocolsAdapting to changes in connectivityReal-time communication, connection oriented!Quality of ServiceSecurity
16 Structure/Backbone (HW) Structure/Backbone (HW)Hardware aspectsbasic aspects (CPU, memory, radio)specific sensors aspects (what type of signals are you measuring?)
19 Equipment Tablet, running the app Static computer for developing EquipmentTablet, running the appStatic computer for developingWireless sensor network to gather data and sent data to the tabletWireless network for the tablet to comunicate with the internetServer for monitoring the app (compressed data)
20 Wireless Sensor Node (1) Wireless Sensor Node (1)Sensor nodessensor technologytiny battery driven computerswireless communication interfaceorganize into a networkmonitoring of processes, environmental conditions, eventsact as routersforward data cooperatively
23 Classifications of sensor network protocols Classifications of sensor network protocols
24 Clustered sensor network architecture Clustered sensor network architectureOrganizes the sensor nodes into clustersEach cluster is governed by a cluster-headOnly heads send messages to a BSSuitable for data fusionSelf-organizing
26 Network Initialization & Maintenance Protocol Network Initialization & Maintenance ProtocolBase Station (BS) broadcasts ID using Code Division Multiple Access (CDMA) common control channel (BS reaches all nodes in one hop)Nodes record BS ID & send beacon signal with their own IDs at their low default power levelsAll nodes the BS can hear are at 1-hop distanceThe BS broadcasts a control packet with all layer one node IDsAll nodes send a beacon signal againThe layer one nodes record the IDs they hear-layer 2The layer one nodes inform the BS of the layer 2The BS broadcasts the layer2 nodes IDs,…To maintain: periodic beaconing updates are required
27 Routing ProtocolDownlink from the BS is by direct broadcast on the control channelEnables multi-hop data forwarding to the BSThe remaining energy is considered when forwarding to the next hop (layer)Only the nodes of the next layer need to be maintained in the routing table
28 Low-Energy Adaptive Clustering Hierarchy (LEACH) Low-Energy Adaptive Clustering Hierarchy (LEACH)Self-organizing and adaptive clustering protocolEvenly distributes the energy expenditure among the sensorsPerforms data aggregation where cluster heads act as aggregation pointsTwo main phases:Setup phase: organizing the clustersSteady-state phase: deals with the actual data transfers to the BS
29 Low-Energy Adaptive Clustering Hierarchy (LEACH) Low-Energy Adaptive Clustering Hierarchy (LEACH)Merits:Accounting for adaptive clusters and rotating cluster headsOpportunity to implement any aggregation function at the cluster headsDemerits:Highly dynamic environmentsContinuous updatesMobility
30 Efficient Data Gathering in WSN Efficient Data Gathering in WSNData gathering from different correlatedcues from the network state uses hints or cues about the physical environment to optimize network behaviorenergy-efficient rooted aggregation trees a simple, scalable and distributed correlation-aware aggregation structurecongestion reduction techniques providing congestion control from the sink to the sensors in a sensor field
31 Medium Access Control Framing Medium Access Reliability Flow Control Medium Access ControlFramingFrame format and data en- and decapsulationMedium AccessWhich devices participate in communication at what timeReliabilitySuccessful transmission between devicesFlow ControlPrevent frame loss through buffer overloadsError ControlError detection or correction
32 Location discovery? Distance estimation Position computation Location discovery?Distance estimationTechniques to estimate the relative distance between nodesPosition computationCalculate coordinates based on known other nodesTriangulation, multilateration, proximityLocalizationBased on information about distances and positions
33 Leftovers Quality of network coverage Security Real time communication LeftoversQuality of network coverageSecurityReal time communication...
35 The internet of things is close! The internet of things is close!What we can do:Acquired dataReports or alarm noticesAutomatically forwarded to information systems
36 The internet of things is close! The internet of things is close!What we can do with this technology:Extending the internet into the real-worldAutonomous Information SystemsAutomatically update themselvesSynchronize with the actual state of monitored structure or process
37 The internet of things is close! The internet of things is close!What we can do with this technology:Near-real-time information enables early interventionPrevent abnormal behaviorMalfunctionDamagesDangerous situations
38 The internet of things is close! The internet of things is close!Typical application domains:Home care and e-health (or t-health)Environmental monitoringFactory automation and maintenanceSupply chain and asset managementPhysical security and control…
41 Wireless Sensor Modules Wireless Sensor ModulesThe iSense modular hardware and software platform for wireless networks for industry and research applications comprises modules for wireless networking, sensors modules, different power supplies, solar power harvesting, interfaces to PCs, GPS and more.
42 Wireless Sensor Solutions Wireless Sensor SolutionsBased upon a broad range of hardware, software and protocol components as well as our different networking devices, coalesenses offers both standardized as well as customer specific wireless sensor networking systems.
43 Solar Power Harvesting Solar Power HarvestingThe iSense Solar Power Harvesting System is an out-of-the-box solution for running self-powered wireless sensor networks. By harvesting solar energy and storing it in a rechargeable battery, it allows to operate sensor nodes all-time autonomously
44 Wireless Sensor Devices Wireless Sensor Devicescoalesenses offers a number of different devices as building blocks for wireless systems, ranging from LAN gateways over repeaters to USB sticks.
45 Wireless Sensor Technology Wireless Sensor Technologycoalesenses offers a collection of hardware and software for wireless sensor networks, a technology for literally giving eyes and ears to modern control and information systems.
47 Wrap up Environment: Main question: Health, Alzheimers Wrap upEnvironment:Health, AlzheimersDomotics, Wireless Sensor NetworksIT, Tablet and internet connectionMain question:How can we add value to the life of a patient with Alzheimers