Content: IntroductionSensorsSensor Node ArchitectureSensor Network ArchitectureMote TechnologyComparison of MANET and WSNRequirements of a WSNChallenges for a WSNWSN ApplicationsChapter NotesBibliographyWireless Sensor Networks ArchitectureIntroductionNetwork Protocol StackCommunication StandardsIEEE 802.11IEEE 802.15.4ZigBee6LoWPANSummaryBibliographyInformation GatheringIntroductionRoutingFlat-based Routing AlgorithmsHierarchical Routing AlgorithmsInformation Gathering Based on Geographic LocationsLocalizationGeographical RoutingLandmark-based RoutingData AggregationContent-based NamingSummary BibliographyEnergy Management in WSNIntroductionDuty CyclingIndependent StrategiesDependent StrategiesIndependent Sleep/Wakeup SchemesAsynchronous SchemesTDMA-based MAC ProtocolsContention-based MAC ProtocolsHybrid MAC ProtocolsData-driven ApproachesData PredictionData SensingEnergy-Aware Routing ProtocolsHierarchical Energy-Aware RoutingLocation-based RoutingData Aggregation-based RoutingRemarksSummaryBibliographySecurity in WSNIntroductionChallenges in WSNAttacks in WSNAttack CategorizationProtection Against AttacksCryptography in WSNKey ManagementKey Management in Distributed WSNKey Management in Hierarchical WSNSecure Routing in WSNsAttacks on Routing ProtocolsCountermeasures for Attacks Intrusion Detection in WSNIntrusion Detection SystemsSummaryBibliographyOperating Systems for WSNsIntroductionArchitectureMonolithicMicro-kernelVirtual MachineExecution ModelEvent-basedThread-basedHybrid ModelsSchedulingPower ManagementCommunicationCase Study: Popular Operating SystemsTinyOS ContikiMagnetOSMantis OSSummaryBibliographyProgramming WSNsIntroductionTinyOSTOSSIMTinyOS InstallationCTP in TinyOSModified SPIN in TinyOSContikiCOOJAContiki InstallationBroadcast Example in ContikiCastaliaModules under CastaliaCastalia InstallationT MAC in CastaliaNS-3 InstallationMobility Model in NS-3SummaryBibliography