Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Ad-hoc On-demand distance vector routing (AODV)Slide 21LEAR – AODVSlide 23Experimental ResultsBalanced Energy Consumption SchemeSlide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41A Survey of Forwarding Strategies for WSN’sAkshay BholeSubhani Basha PetaMeena Krishnappa CEN 5531 - Mobile ComputingFall 2006Outline Introduction Traditional Forwarding Strategies Energy Efficient Forwarding Scheme Balanced Energy Consumption Scheme Supply Chain Scheme Comparison ConclusionOutline Introduction Traditional Forwarding Strategies Energy Efficient Forwarding Scheme Balanced Energy Consumption Scheme Supply Chain Scheme Comparison ConclusionMotivation Search for efficient path from Source to Sink Traditional Methods• Minimize Transmissions• Maximize end-to-end delivery No focus on Energy Efficiency Energy Efficiency gives better Trade-off between Delivery Rate & Required EnergyIntroductionOutline Introduction Traditional Forwarding Strategies Energy Efficient Forwarding Scheme Balanced Energy Consumption Scheme Supply Chain Scheme Comparison ConclusionTraditional Methods• Hop Based Forwarding• Optimal Hop Based Forwarding• PRR Based Forwarding• MT Forwarding• Er based ForwardingHop Based ForwardingTraditional MethodsIdea •Establish reverse path using a hop counter• Packets are forwarded along the reverse path with decreasing hop countersDrawback• Neighboring nodes may have lossy links• Neighboring node might be too far away• Many retransmissions might be necessaryTraditional MethodsPRR Based ForwardingIdeaDowngrade neighbor nodes having low hop counter and poor linksForwarding nodes selection based on• Distance• Link QualitySelection of best forwarder done by minimizingTraditional MethodsMT ForwardingIdeaMinimize the overall packet transmissions along the source-to-sink path.Drawback• delivery rate not considered• might not be the most energy-efficient forwarding strategy for Re-Transmissions ≠ ∞Traditional MethodsEr based ForwardingIdeaFocus on the end-to-end delivery rate and attempts to maximize EirDrawbackDoesn’t work well with Multi-Link Forwarding StrategiesOutline Introduction Traditional Forwarding Strategies Energy Efficient Forwarding Scheme Balanced Energy Consumption Scheme Supply Chain Scheme Comparison ConclusionEnergy Efficient ForwardingIdeaTo find the most energy-efficient forwarding path in the networkTypes of Energy Efficient Forwarding SchemesSingle LinkMulti LinkHow is it done?• Forwarding Set – Identify Potential Forwarding nodes• Node that maximizes Eieff is selected as the forwarder• End-to-End reception rate and Energy is taken into accountEnergy Efficient ForwardingComparison of Single-Link & Multi-LinkEnergy Efficient ForwardingSingle Link Multi LinkPackets addressed to single forwarderPackets addressed to a set of Forwarding nodesLess ReliableMore reliable as it uses Multi path routingLess Robust More robust & fault tolerantNo need of using broadcastUses Broadcast channel of the networkPRR depends on type and quality of neighboring nodeBetter choice of PRRTraditional v/s EEFEnergy Efficient ForwardingInfluence of Node DensityTraditional v/s EEFEnergy Efficient ForwardingInfluence of contention probabilitiesTraditional v/s EEFEnergy Efficient ForwardingInfluence of receiving energy costsOutline Introduction Traditional Forwarding Strategies Energy Efficient Forwarding Scheme Balanced Energy Consumption Scheme Supply Chain Scheme Comparison ConclusionBalanced Energy Consumption SchemeFactors to be considered while designing routing protocols•Energy Conservation•Network Lifetime•End-to-End Delivery RateDo Shortest Path algorithms provide a good solution?Energy Efficient Routing AlgorithmsBalanced Energy Consumption SchemeLEAR(AODV) : Local Energy Aware Routing based on AODVPAR(AODV) : Power Aware Routing based on AODVLPR(AODV) : Lifetime Prediction Routing based on AODVDo you have a route to destination?Ad-hoc On-demand distance vector routing (AODV)Balanced Energy Consumption SchemeReverse Path EstablishedAd-hoc On-demand distance vector routing (AODV)Balanced Energy Consumption SchemeRouting Metric – Remaining Battery Life (Er)Is Er >  ? LEAR – AODVBalanced Energy Consumption SchemeRouting Metric – Remaining Battery Life (Er)Reverse pathEstablishedLEAR – AODVBalanced Energy Consumption SchemeFixed Nodes : Experimental ResultsBalanced Energy Consumption SchemeMobile Nodes : Balanced Energy Consumption SchemeOutline Introduction Traditional Forwarding Strategies Energy Efficient Forwarding Scheme Balanced Energy Consumption Scheme Supply Chain Scheme Comparison ConclusionWhat is Supply chain ?Supply Chain ForwardingDifferent Strategies: Push Strategies Pull Strategies Hybrid StrategiesSupply Chain ForwardingSupply Chain SchemeModeling Sensor Networks as Supply ChainSupply Chain SchemeItems in Supply ChainCounterparts in Sensor NetworksRaw materials or parts Phenomena of Interest.Suppliers or ManufacturesSensor nodes generating dataTransportation Network Intermediate Sensor nodesDistributors Sink NodesFinished Product Data Processed by Sink NodesConsumers End users of the data offered bythe sink nodeModeling Sensor Networks as Supply ChainRouting ProtocolsSupply Chain Scheme Data Diffusion – Pull strategy Spin – Push StrategySupply Chain SchemeSystem ModelManufacture Area: Data Collection Data Aggregation Decision regarding the Forwarding schemeTransport Area: Zone Flooding SchemeSupply Chain SchemeParts of the NetworkSupply Chain SchemeParts of the Network Sensor Field Partition is only conceptual and application dependent  Different Forwarding Mechanisms•Local Broadcasting in manufacture area•Zone Flooding in Transportation area•Unicast based routing in Warehouse area Supply Chain SchemeNovel Features Scalable and flexible, and reduces the difficulty of designing a feasible overall routing scheme Zone flooding scheme attempts to improve the energy efficiency of flooding by restricting the flooding range in the spatial domain and