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WSN presentation

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WSN presentation

  1. 1. Graduate Project Presentation TCET.797.01 Presented By – Braj Raj Singh Telecommunication Engineering Technology Efficient Data Aggregation from polling points in Wireless Sensor Network
  2. 2. Background- 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.
  4. 4. Wireless Sensor Network A 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 Reliability • Self-Configurability • Flexible Topology Changes • Self-organized • No wired infrastructure • Potential multi-hop routes • Ability to withstand in harsh environmental conditional
  5. 5. Applications of WSN-  The Military Applications  The Medical Applications  Environmental Monitoring  Target tracking  Industrial Application  Infrastructure and protection application
  6. 6. Topology of Wireless Sensor Network • Point 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.
  7. 7. 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- 1. Sensor Nodes (SN) 2. Cluster Head (CH) 3. Mobile Collector (MS) 4. Rendezvous Nodes /Polling Points 5. Base Station
  8. 8. 1.Sensor Node  Processing Unit (microcontroller/microprocessor)  Sensing Unit (A/D convertor)  Power supply (battery)  Communication Unit (radio trans-receiver) Power Supply Microcontroller Analog to Digital Convertor S1 S2 External Memory Trans receiver
  9. 9. 2. 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
  10. 10. 3. Mobile collector Mobile Collector Data 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- a) Random b) Predictable (their movement pattern is known before hand) c) Controlled (their movement is actively controlled in real time)
  11. 11. 4. 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 for • relatively long time, in relatively short distance from the sink's trajectory and have sufficient energy supplies. Polling Point Sink Trajectory
  12. 12. 5. 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.
  14. 14. 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. Cluster Head Mobile Sink Data Aggrega on Cluster Head Elec on Cluster Forma on Sensor Nodes Sensory Data Cluster forma on and Data Collec on approach by Mobile Sink from Sensor Nodes
  15. 15. Clustering Objectives  Support Network Scalability  Decrease energy consumption through data aggregation  Limits data transmission (load balancing)  Facilitate the reusability of the resources  Conserve communication bandwidth  Cluster Head and gateway nodes can form a virtual backbone for inter- cluster routing  Cluster structure gives the impression of a smaller and more stable network  Improve network lifetime  Reduce network traffic and the contention for the channel  Data aggregation and updates take place in CHs
  16. 16. Types of Clustering
  17. 17. Cluster Communication Clustering 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- CH CH CH Base Sta on Intra-cluster Inter-cluster
  18. 18. Base Sta on Sensor Nodes Deployed in a Region Sensor informa on forwarding without clustering –Single hop Mechanism
  19. 19. Base Sta on Sensor Nodes Deployed in a Region Sensor informa on forwarding without clustering –Mul -hop Mechanism Sensor Nodes
  20. 20. Base Sta on Sensor Nodes Deployed in a Region Sensor informa on forwarding with clustering –Single hop Mechanism Cluster Forma on Cluster Head Sensor Nodes
  21. 21. Base Sta on Sensor Nodes Deployed in a Region Sensor informa on forwarding with clustering –Mul -hop Mechanism Cluster Forma on Cluster Head Sensor Nodes
  22. 22. ROUTING3
  23. 23. Routing Routing has two main function- Route Discovery and Packet forwarding . The major requirements of a routing protocol- • Minimum route acquisition delay • Quick route reconfiguration in the case of path breaks. • Loop-free routing • Distributed routing protocol • Low control over-head • Scalability with network size • QoS support as demanded by the application • Support of time-sensitive traffic and • Security and privacy
  24. 24. Types of Routing - Rou ng Protocol Flat Hierarchic Proac ve Reac ve DSDV AODV/DSR
  25. 25. Proactive Vs. Reactive- Proactive (Table Driven) Reactive (On- Demand) Route from each node to every other node in the network Routes from Source to Destination only Routes are ready to use instantaneously Routes constructed when needed, higher connection setup delay Periodic route-update packets Route update when necessary Changes to network topology immediately propagated Changes to network topology not propagated immediately Large routing tables Small or No routing tables
  26. 26. AODV Routing Protocol Reactive or on Demand Uses bi-directional links Route discovery cycle used for route based on requirement Sequence numbers used for loop prevention and as route freshness criteria Provides unicast and multicast communication Maintain Active routes. Whenever routes are not used -> get expired->Discarded – Reduces stale routes – Reduces need for route maintenance
  27. 27. AODV Routing Table In 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
  28. 28. 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 Flooding
  29. 29. Route Request Propagation ( RREQ)
  30. 30. 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.
  31. 31. 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 to route 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 breaks 2. Node C invalidates route to D in route table 3. Node C creates Route Error message • Lists all destinations that are now unreachable • Sends to upstream neighbors
  32. 32. 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
  33. 33. 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-D because RERR sent by C is lost Now C performs a route discovery for D. Node A receives the RREQ (say, via path C-E-A) • Node A will reply since A knows a route to D via node B • Results 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 the sequence numbers will be lower than what A receives from A
  34. 34. DSDV Routing Protocol  The 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.
  35. 35. DSDV DSDV adds two things to distance vector routing – a) Sequence number that avoid loops b) Damping- 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 – a) Chose the one with greatest destination sequence number b) If equal chose the smaller metric (hop count)
  36. 36. DSDV Table structure Sequence 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. Destination Next Metric Seq. Nr Install Time Stable Data A A 0 A-550 001000 Ptr_A B B 1 B-102 001200 Ptr_B C B 3 C-588 001200 Ptr_C D B 4 D-312 001200 Ptr_D
  37. 37. Proposed System-Mobi Cluster Mobile Sink Trajectory Base Sta on 1 Base Sta on 2 Mobile Collector 1 Mobile Collector 2 Cluster Cluster Head Sensor Nodes Polling Point/Rendezvous Node
  38. 38. System Flow Diagram-
  39. 39. Mobi-Cluster Protocol Concept- • 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 Selection 2. Polling point selection 3. Cluster Head attachment to Polling points 4. Data Aggregation and forwarding to Polling points 5. Communication between Poling point and Mobile collector(data)
  40. 40. Clustering Mechanism Mobi-Cluster Protocol 2 3 4 51 Ini al 3 Phase are-Set up Phase Last two phases are steady phase In Setup phase mobile sink complete a single trip while broadcas ng beacon message periodically . Sensor in the Network used this ‘Beacon’ message to determine number of important parameter for protocol opera on In steady Phase sensor data rou nely gathered and sent to mobile sink. This phase includes reselec on of Rendezvous nodes and local re- clustering . Local Re-Clustering performed when some important nodes suffer from energy exhaus on condi on
  41. 41. Overall Flow-diagram
  42. 42. Project Implementation
  43. 43. Simulation Procedure  Implementation 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 it’s 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.
  44. 44. Simulation NS-2 Features  It is a discrete event simulator that is object oriented  C++ event scheduler is implemented in the back end  OTCL is implemented in front end  NS-2 can be used on UNIX as well Windows operating system( with Cygwin)
  45. 45. Layered Architecture of NS-2 Simula on Scenario 1 2 Set ns_ [new Simulator] Set node_(0) [$ns_node] Set node_(1) [$ns_node] C++ Implementa on Class MobileNode :public Node { Friend class posi on handler; Public: MobileNode (); } Network scheduler and network component are implemented by c++ Layered Architecture of NS2 ( Network Simulator)
  46. 46. Future Approach- Enhance Data Aggregation strategy (Using Remote Agent)
  47. 47. 1. PDR 2. Throughput 3. Residual Energy 4. Delay COMPARISON BASED ANALYSIS5
  48. 48. PDR ( Packet Delivery Ratio)- PDR= No of packet received by destination / No of packet sent by content based source 0.00% 20.00% 40.00% 60.00% 80.00% 100.00% AODV DSDV PDR AODV DSDV
  49. 49. Total Energy Consumption 450 500 550 600 650 AODV DSDV Total Energy Consumption (Kbps) AODV DSDV
  50. 50. Throughput Throughput 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 AODV DSDV
  51. 51. References-  Wireless/intro.html  df            
  52. 52. 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, IEEE  Sencar: An Energy-Efficient Data Gathering Mechanism For Large-Scale Multi-Hop Sensor Networks Ming Ma, Student Member, IEEE, and Yuanyuan Yang, Senior Member, IEEE  Energy-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, IEEE  Adaptive Sink Mobility in Event-Driven Densely Deployed Wireless Sensor Networks Zoltán Vincze1, Dorottya Vass1, Rolland Vida1, Attila Vidács1 and András Telcs2  Optimal Speed Control of Mobile Node for Data Collection in Sensor Networks Ryo Sugihara, Student Member, IEEE, and Rajesh K. Gupta, Fellow, IEEE  Joint Mobility and Routing for Lifetime Elongation in Wireless Sensor Networks Jun Luo Jean-Pierre Hubaux  Clustering in Wireless Sensor Networks Basilis Mamalis, Damianos Gavalas, Charalampos Konstantopoulos, and Grammati Pantziou  Prolonging the Lifetime of Wireless Sensor Networks via Unequal Clustering Stanislava Soro and Wendi B. Heinzelman
  53. 53. Questions