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Graduate Project Presentation TCET.797.01 Presented By Braj Raj Singh Telecommunication Engineering Technology Efficient Data Aggregation from polling points in Wireless Sensor Network

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Graduate Project PresentationTCET.797.01Presented By Braj Raj SinghTelecommunication Engineering TechnologyEfficient Data Aggregation from polling points in Wireless Sensor Network

1Background-Existing System-A number of approaches exploiting sink mobility for data collection in wireless sensor networks have been proposed in recent years.In single hop communication, we can minimize energy consumption, however, at the expense of high data delivery delay.In the second solution, this delay is low but the energy consumption due to multi hop communication is rather high.

Proposed System- Our proposed protocol aims at minimizing the overall network overhead and energy expenditure associated with the multi hop data retrieval process while also ensuring balanced energy consumption among sensor nodes and prolonged network lifetime. This is achieved through building cluster structures consisted of member nodes that route their measured data to their assigned cluster head (CH). Clustering has proven to be an effective approach for organizing the network in the above context. Besides achieving energy efficiency, clustering also reduces channel contention and packet collisions, resulting in improved network throughput under high load. Wireless sensor NETWORK (WSN)1

Wireless Sensor NetworkA Collection of Spatially Distributed Organized autonomous sensor nodes that collects data from its surrounding.The Wireless sensor network is a combination of wireless sensing and data networking that consists of protocols and algorithms with self-organizing capabilities and can be used in safety-critical or highly reliable applications

Important Characteristics-

Scalability and ReliabilitySelf-ConfigurabilityFlexible Topology ChangesSelf-organizedNo wired infrastructurePotential multi-hop routesAbility to withstand in harsh environmental conditional

4Applications of WSN- The Military ApplicationsThe Medical ApplicationsEnvironmental Monitoring Target tracking Industrial ApplicationInfrastructure and protection application

The Military Applications- The military application of sensor nodes include battle field surveillances and monitoring, guiding system of intelligent missile and detection of attack by weapons of mass destruction.

The Medical Applications sensor are extremely useful in patient diagnosis and monitoring . Patient can wear small sensor devices that monitor the physiological data like heart rate blood pressure.Environmental Monitoring This include traffic ,habitat , wild lifeTarget tracking Industrial Application- it include industrial sensing and diagnostic Infrastructure and protection application- it is use for power grid monitoring and water distribution monitoring.

5Topology of Wireless Sensor NetworkPoint to point (Peer to Peer) topology- In this type of network topology nodes are involved in direct node-to-node communication without going through centralized communication hub. Each peer is able to work as either client or server.Star topology- In star topology, each node must communicate through a centralized connected hub. Information cannot be directly routed through node-to-node .The centralized hub works as server and connecting nodes works as clients.Tree based topology- In a tree based topology, the centralized node functions as root node. A root node has a central hub that is one step down in hierarchy. This lower level then forms a star based network, which is why a tree network is also called hybrid network.Meshed Network topology- Mesh networks have a self-healing property because it allows data to hop from node to node. This type of network is very complex as compared to other topologies and is more cost effective.

Architecture of Wireless Sensor Network Wireless sensor network composed of two distinct layers

Sensor and Networking layers Distributed Service layer

Key component of Sensor Network-Sensor Nodes (SN)Cluster Head (CH) Mobile Collector (MS) Rendezvous Nodes /Polling Points Base Station

1.Sensor NodeProcessing Unit (microcontroller/microprocessor) Sensing Unit (A/D convertor) Power supply (battery) Communication Unit (radio trans-receiver)

Wireless Sensor network is built up of several nodes interconnected with each other. They may vary in size from a shoebox to a size of tiny grain. These small size sensor nodes are equipped with embedded microprocessor and radio transceiver and capable of sensing, communication and data processing. The sensor Network consists of base stations and many wireless sensor nodes.

Structure of Sensor Node-Sensor Node is composed of Sensing unit, a processing unit, Communication unit and power unit. Sensing unit basically consists of Analog to Digital convertor. These sensor nodes have the capability of sensing, computation and wireless communication. Sensor nodes observe the physical phenomenon and generate analog signal based upon that. Processing unit consists of either a microcontroller or microprocessor that provides intelligence control to sensor nodes. Communication unit consists of short-range radio for data transmission purpose.

82. Cluster Head ( CH) In wireless sensor network, small group of sensor node formed a cluster and each cluster has a coordinator referred Cluster head (CH). Cluster head selection has impact on network lifetime. Cluster Head should be reachable in a single hop from their cluster members.

Primary function of Cluster head

Aggregate data from respective sensor node and transferred to remote processing element.Localization of network traffic. CH implement network management strategy to enhance network operation and prolong the battery life.Reduce the rate of energy consumption by schedule activity activities in the cluster so sensor node can switch to low power sleep mode

3. Mobile collector

Mobile CollectorData Collector (Sink) can be classified in two category-

Static Collector- Network sink nodes are on fixed position; either close or inside the sensing region that makes network simpler to control.

Mobile Collector-The Mobile Collector (MC) moving through the network deployment region can collect data from the static sensor nodes over a single hop radio link when approaching within the radio range of the sensor nodes or with limited hop transfers if the sensor nodes are located further.

Mobility pattern of Data collector-RandomPredictable (their movement pattern is known before hand)Controlled (their movement is actively controlled in real time) This approach avoids longhop relaying and reduces energy consumption at sensor nodes near the base station, prolonging the network lifetime.

104. Polling Points /Rendezvous Nodes-

Polling points guarantee connectivity of sensor clusters with Mobile collector. Their selection largely determines network lifetime. Polling points are selected among candidate Sensor node typically located in the periphery of the sensor island and lie within the range of mobile collector. Suitable polling points are those that remain within the Mobile collector range forrelatively long time, in relatively short distance from the sink's trajectory and have sufficient energy supplies.Polling PointSink Trajectory5. Base Station

The base stations are one or more components of the WSN with more computational energy and communication resources. They act as a gateway between sensor nodes and the end user as they typically forward data from the wireless sensor network on to a server.

Clustering Mechanism2

Clustering Clustering is a process of logical grouping of similar sensors to achieve load balancing and network scalability . Clustering is an effective approach for organizing the network that reduces channel contention, packet collision and improved network throughput under high load.

Clustering Objectives

Support Network ScalabilityDecrease energy consumption through data aggregationLimits data transmission (load balancing)Facilitate the reusability of the resourcesConserve communication bandwidthCluster Head and gateway nodes can form a virtual backbone for inter-cluster routingCluster structure gives the impression of a smaller and more stable networkImprove network lifetimeReduce network traffic and the contention for the channelData aggregation and updates take place in CHs

Types of Clustering

Cluster CommunicationClustering support network scalability and reduces energy consumption through efficient data aggregation. It can localize the route setup with in the cluster and thus reduce the size of routing table that help to stabilize network topology. Cluster communication can be classified as-

Routing 3

RoutingRouting has two main function- Route Discovery and Packet forwarding .

The major requirements of a routing protocol-

Minimum route acquisition delayQuick route reconfiguration in the case of path breaks.Loop-free routingDistributed routing protocolLow control over-headScalability with network sizeQoS support as demanded by the applicationSupport of time-sensitive traffic andSecurity and privacy

Types of Routing -

Notes- Routing is fundamental for wireless sensor network because there is no infrastructure that manages information between nodes so each network node act as router . It is difficult for ensure best suitable routing protocol for such type of network .To specify a significant protocol we followed some strategy. Routing protocol has two class flat and hierarchical. Flat routing is further classified in two category Proactive and reactive . Flat-basedAll nodes are typically assigned equal roles or functionality.

Hierarchical-basedNodes will play different roles in the network.

24Proactive Vs. Reactive-Proactive (Table Driven)Reactive (On- Demand)Route from each node to every other node in the networkRoutes from Source to Destination only Routes are ready to use instantaneouslyRoutes constructed when needed, higher connection setup delayPeriodic route-update packets Route update when necessary Changes to network topology immediately propagatedChanges to network topology not propagated immediatelyLarge routing tablesSmall or No routing tables


Proactive Routing Protocols (Table-driven)Nodes exchange routing information periodically in order to maintain consistent and accurate information. To transmit data to a destination, path can be computed rapidly based on the updated information available in the routing table. The disadvantage of using a proactive protocol is high overhead needed to dynamic topology that might require a large number of routing updates.Each node maintains a routing table, with an entry for each possible destination address, next hop on the shortest path to that destination, shortest known distance to this destination, and a destination sequence number that is created by the destination itself.

Reactive Routing Protocols (On-demand) Route discovery mechanism is initiated only when a node does not know the path to a destination it wants to communicate with. In case of mobile ad hoc network, reactive routing protocols have been demonstrated to perform better with significantly lower changes that may occur in node connectivity, and yet are able to reduce/eliminate routing overhead in periods or areas of the network in which changes are less frequent.A reactive routing has two main operations-Route discovery Route maintenance. Various reactive protocols have been proposed such as Ad Hoc On-demand vector (AODV), Dynamic source routing (DSR), Temporary Ordered Routing Algorithm (TORA), etc.

25AODV Routing ProtocolReactive or on DemandUses bi-directional linksRoute discovery cycle used for route based on requirementSequence numbers used for loop prevention and as route freshness criteriaProvides unicast and multicast communicationMaintain Active routes.Whenever routes are not used -> get expired->DiscardedReduces stale routesReduces need for route maintenance

26AODV Routing TableIn AODV each node maintain a routing table this routing table contains information about reaching destination nodes .The routing table field includes- Destination IP address, destination sequence number, valid destination sequence number flag, Network interface, hop count, next hop, precursor list and life time which is normally route expiration or deletion time

AODV Route Discovery Mechanism

In AODV protocol when a node willing to send a packet to some Destination .It checks its routing table to determine if it has a current route to the destination-

If Yes, forwards the packet to next hop node If No, it initiates a route discovery process

Route discovery process begins with the creation of a Route Request (RREQ) packet -> source node RREQ- route request-RREQ contain most recent sequence number of the destination. RREQ is broadcasted when a node needs to discover a route to its destination. As this message propagate through a network intermediate nodes use it to update their routing table.

Packet also contains broadcast ID number, Broadcast ID gets incremented each time a source node uses RREQ Broadcast ID and source IP address form a unique identifier for the RREQ Broadcasting is done via FloodingRoute Request Propagation ( RREQ)

Propagation of Route Reply (RREP) message-When a RREQ reaches a destination node the destination route is made available by Unicast a RREP back to the source route. A node generate RREP if it has an active route to destination. As RREP propagate back to the source node, intermediate nodes update their routing table.

Route Error Message ( RERR)-RERR is initiated by the node upstream (closer to the source) of the break Its propagated to all the affected destinations RERR lists all the nodes affected by the link failure -> Nodes that were using the link toroute messages (precursor nodes) When a node receives an RERR, it marks its route to the destination as invalid -> Setting distance to the destination as infinity in the route table When a source node receives an RRER, it can reinitiate the route discovery

1. Link between C and D breaks2. Node C invalidates route to D in route table3. Node C creates Route Error messageLists all destinations that are now unreachable Sends to upstream neighbors

Route Maintenance Mechanism-

Node A receives RERR

Checks whether C is its next hop on route to D Deletes route to D (makes distance -> infinity) Forwards RERR to S

Node S receives RERR

Checks whether A is its next hop on route to D Deletes route to D Rediscovers route if still needed

Importance of Sequence Number -Sequence numbers used for route freshness and loop prevention

To prevent formation of loops A had a route to D initially Assume that A does not know about failure of link C-Dbecause RERR sent by C is lostNow C performs a route discovery for D. Node Areceives the RREQ (say, via path C-E-A)Node A will reply since A knows a route to D via node BResults in a loop (for instance, C-E-A-B-C )

Loop C-E-A-B-C Because of usage of sequence number, A will not use the route A-B-C, because thesequence numbers will be lower than what Areceives from A

DSDV Routing ProtocolThe DSDV routing protocol is an enhanced version of the distributed Bellman-Ford algorithm where each node maintain a table that contain the shortest distance and the first node on the shortest path to every other node in the network.

Routing table updates are periodically transmitted.

To minimize the routing updates, variable sized update packets are used depending on the number of topological changes.

Each entry in the table is marked by a sequence number which helps to distinguish stale routes from new ones, and thereby avoiding loops.

When a route update with higher sequence number is received, the old route is replaced. And when there are two different routes exist with same sequence number the route with better matrix is used.

DSDVDSDV adds two things to distance vector routing Sequence number that avoid loopsDamping- hold advertisement for changes of short duration Each node periodically transmits update that includes own sequence number and routing table update.Node also send routing table update for important link changes.When two to a destination received from two different neighbors Chose the one with greatest destination sequence numberIf equal chose the smaller metric (hop count)

DSDV Table structureSequence Number- sequence number originated from destination number and it ensures loop freeness.

Install time when entry was made (Used to delete stale entry from the table)

Stable Data -Pointer to a table holding information on how stable a route is. Used to damp fluctuations in network.The main advantage of DSDV protocol is this is loop free through destination sequence number and there is no latency caused by route discovery. But it has overhead issue because most routing information is never used.DestinationNextMetricSeq. NrInstall TimeStable DataAA0A-550001000Ptr_ABB1B-102001200Ptr_BCB3C-588001200Ptr_CDB4D-312001200Ptr_D

Sequence number indicate route age.36Proposed System-Mobi Cluster

System Flow Diagram-


Sensor Node Deployment-The sensor nodes have predefined data collection region. This data collection region is represented with topography coordinates X and Y. In our project, terrain range (X and Y coordinates) is 1070, 1070.Clustering- These sensor nodes (53) form a group together known as a cluster. Every cluster has a cluster head (CH). Each remaining node in a cluster except the Cluster Head is called a Cluster Candidate. Cluster Size- Position of base station with respect to cluster head is a key parameter to decide cluster size for example if cluster head is far away from the base station the size of cluster reduces and when it come closer to the base station the cluster size increases.Clusters with their cluster heads near the mobile sink trajectory are small because of the heavy relay traffic coming from other parts of the network. This way, the cluster heads do not have to perform inter-cluster processing and communication tasks.Rendezvous node/polling point selection- The rendezvous nodes guarantee connectivity of Sensor Island with Mobile Sink. The selection of these nodes has a huge impact on network lifetime. After that, Rendezvous node is to be selected which is the back up node.After collecting the data from cluster candidates, the Cluster Head sends the data to rendezvous node. Mobile sink is a device, which is similar to vehicle. It moves to the Rendezvous nodes coverage area and collects the data from all rendezvous nodes.

38Mobi-Cluster ProtocolConcept- Mobi-cluster protocol helps to ensures delivery of data even through multi-hop transfers from source sensor nodes located far from the mobile sink trajectories.

Building hierarchical cluster structures comprising neighbor sensor node to increase the performance of intra-cluster data filtering and minimize the data relaying overhead.

Emphasis is given on selecting the appropriate polling points among Sensor nodes located in the periphery of the sensor islands (so that they remain within the range of MSs for sufficient time and they buffer data from balanced-sized groups of source SNs)

Five stages of Mobi-Cluster Protocol-

1.Cluster Head Selection2. Polling point selection3. Cluster Head attachment to Polling points4. Data Aggregation and forwarding to Polling points5. Communication between Poling point and Mobile collector(data)

Overall Flow-diagram

4Project Implementation

Project Implementation has two types of models- Mobility generation model It is used to study the effect of mobility of nodes on overall performance of the network.Traffic generation model- it is used to study the effect of traffic load on the the network .

42Simulation ProcedureImplementation is the stage of the project when the theoretical design is turned out into a working system. Thus it can be considered to be the most critical stage in achieving a successful new system and in giving the user, confidence that the new system will work and be effective.

The implementation stage involves careful planning, investigation of the existing system and its constraints on implementation, designing of methods to achieve changeover and evaluation of changeover methods. The process of putting the developed system in actual use is called system implementation.

Implementation is the final phase. It involves user training, system testing and successful running of developed system.

Simulation NS-2 Features

It is a discrete event simulator that is object orientedC++ event scheduler is implemented in the back endOTCL is implemented in front endNS-2 can be used on UNIX as well Windows operating system( with Cygwin)

Layered Architecture of NS-2

Layered Architecture of NS2 has shown below it has three layers last layer includes Implementation part that require C++ programing. In the middle layer, Network Scheduler and other components are implemented with C++ programing language. Tcl /OTcl is a scripting Interpreter that help to setup and run simulation. Upper layer contain Simulation scenario.

An event in NS is a packet ID that is unique for a packet with scheduled time and the pointer to an object that handles even . Event scheduler keep track of simulation time and fires all event in the event queue.


Future Approach- Enhance Data Aggregation strategy (Using Remote Agent)

PDRThroughput Residual Energy Delay Comparison based Analysis5


PDR ( Packet Delivery Ratio)-

PDR= No of packet received by destination / No of packet sent by content based source

Total Energy Consumption

ThroughputThroughput calculation provides information about successful data delivery from a receiver to a sender over communication stream; this communication steam can be either logical or physical link .The data transmission calculated in bits per second or kilobits per second. For efficient network a routing protocol with higher throughput is desirable



References-Rendezvous Planning In Wireless Sensor Networks With Mobile Elements Guoliang Xing, Member, IEEE, Tian Wang, Student Member, IEEE, Zhihui Xie, and Weijia Jia, Senior Member, IEEESencar: An Energy-Efficient Data Gathering Mechanism For Large-Scale Multi-Hop Sensor Networks Ming Ma, Student Member, IEEE, and Yuanyuan Yang, Senior Member, IEEEEnergy-Efficient Mobile Data Collection In Wireless Sensor Networks With Delay Reduction Using Wireless Communication Arun K. Kumar and Krishna M. Sivalingam Dept. of Computer Science and Engineering, Mobile Element Scheduling with Dynamic Deadlines Arun A. Somasundara, Aditya Ramamoorthy, Member, IEEE, and Mani B. Srivastava, Senior Member, IEEEAdaptive Sink Mobility in Event-Driven Densely Deployed Wireless Sensor Networks Zoltn Vincze1, Dorottya Vass1, Rolland Vida1, Attila Vidcs1 and Andrs Telcs2Optimal Speed Control of Mobile Node for Data Collection in Sensor Networks Ryo Sugihara, Student Member, IEEE, and Rajesh K. Gupta, Fellow, IEEEJoint Mobility and Routing for Lifetime Elongation in Wireless Sensor Networks Jun Luo Jean-Pierre HubauxClustering in Wireless Sensor Networks Basilis Mamalis, Damianos Gavalas, Charalampos Konstantopoulos, and Grammati PantziouProlonging the Lifetime of Wireless Sensor Networks via Unequal Clustering Stanislava Soro and Wendi B. Heinzelman53Questions