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Ppt on low power wireless sensor network 5th sem

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this is all about low power wireless sensor network.this is my seminar topic in 5yh sem. i am student of jiet group of institute.

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Ppt on low power wireless sensor network 5th sem

  1. 1. LOW POWER WIRELESS SENSOR NETWORK Shikha yadav 12EJTEC075 ECE, 5th sem 1
  2. 2. CONTENTS  Introduction  Definition  Example of WSN  Types of WSN  Characteristics of a WSN  Power saving protocols for WSN  Applications  Challenges  Advantages  Disadvantages  Future Scope  Conclusion 2
  3. 3. INTRODUCTION 3  Low power wireless sensor Networks are networks that consists of sensors which are distributed in an ad hoc manner.  These sensors work with each other to sense some physical phenomenon and then the information gathered is processed to get relevant results.  Low power Wireless sensor networks consists of protocols and algorithms with self-organizing capabilities.
  4. 4. CONTINUED.........  Sensor networks are highly distributed networks of small, lightweight wireless node, deployed in large numbers to monitor the environment or system.  Each node of the sensor networks consist of three subsystem:  Sensor subsystem: senses the environment  Processing subsystem: performs local computations on the sensed data  Communication subsystem: responsible for message exchange with neighboring sensor nodes  The features of sensor nodes  Limited sensing region, processing power, energy 4
  5. 5. 5 DEFINITION Low power Wireless Sensor Networks : Highly distributed networks of small, lightweight wireless nodes, Deployed in large numbers, Monitors the environment or system by measuring phys parameters such as temperature, pressure, humidity. Node: sensing + processing + communication
  7. 7. TYPES OF WIRELESS SENSOR NETWORKS 7  Dense collection of nodes  Ad-hoc deployment  Difficulty in network maintenance  Few and scarcely distributed nodes  Pre-planned deployment  Lower network maintenance Unstructured WSN Structured WSN
  8. 8. CHARACTERISTICS OF A LPWSN 1. Self – Organization 2. Concurrency processing 3. Low cost 4. Restricted energy resources 5. Tiny 6. Small radio range 8
  9. 9. 9 POWER SAVING PROTOCOLS THERE ARE SOME PROTOCOLS WHICH IS USED FOR POWER SAVING……..  Unified Network Protocol Framework (UNPF)  Low-Energy Adaptive Clustering Hierarchy (LEACH)  MAC PROTOCOL  NETWORK LAYER  BATTERY MODEL and some other…
  10. 10. 10 LAYERED ARCHITECTURE  A single powerful base station (BS)  Layers of sensor nodes around BS  Layer i: All nodes i-hop away from BS  Applications:  In-building: BS is an access point  Military  Short-distance, low power tt tx
  11. 11. 11 UNIFIED NETWORK PROTOCOL FRAMEWORK (UNPF)  A layered architecture  A set of protocols  Integrates three operations:  Network Initialization & Maintenance Protocol  MAC Protocol  Routing Protocol
  12. 12. 12 UNIFIED NETWORK PROTOCOL FRAMEWORK (UNPF)  Network Initialization & Maintenance Protocol:  BS broadcasts its ID using 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 levels  All nodes the BS can hear are at 1-hop distance  The BS broadcasts a control packet with all layer one node IDs  All nodes send a beacon signal again  The layer one nodes record the IDs they hear-layer 2  The layer one nodes inform the BS of the layer 2  The BS broadcasts the layer2 nodes IDs,…  To maintain: periodic beaconing updates are required
  13. 13. 13 POWER SAVING MODE  Turning the transceiver off may not always be efficient. Operation in a power-saving mode is energy-efficient only if the time spent in that mode is greater than a certain threshold MULTIPLE HOPS  Using several short hops may be more energy efficient than using one large hop.
  14. 14. 14 CLUSTERED ARCHITECTURE  A clustered architecture organizes the sensor nodes into clusters, each governed by a cluster-head. The nodes in each cluster are involved in message exchanges with their cluster-heads, and these heads send message to a BS.  Clustered architecture is useful for sensor networks because of its inherent suitability for data fusion. The data gathered by all member of the cluster can be fused at the cluster-head, and only the resulting information needs to be communicated to the BS.  The cluster formation and election of cluster-heads must be an autonomous, distributed process.
  16. 16. 16 LOW-ENERGY ADAPTIVE CLUSTERING HIERARCHY (LEACH)  Self-organizing and adaptive clustering protocol  Evenly distributes the energy expenditure among the sensors  Performs data aggregation where cluster heads act as aggregation points  Two main phases:  Setup phase: organizing the clusters  Steady-state phase: deals with the actual data transfers to the BS
  17. 17. 17  Setup phase:  Each sensor chooses a random number m between 0 and 1  If m < T(n) for node n, the node becomes a cluster-head where  P : the desired percentage of cluster heads  r : the round number  G : the set of nodes that have not been cluster heads during the last 1 / P rounds  A cluster head advertises its neighbors using a CSMA MAC.  Surrounding nodes decide which cluster to join based on the signal strength of these messages  Cluster heads assign a TDMA schedule for their members 1 [ * mod(1/ )]( ) 0 , P if n G P r PT n otherwise      
  18. 18. 18  Steady-state phase:  All source nodes send their data to their cluster heads  Cluster heads perform data aggregation/fusion through local transmission  Cluster heads send them back to the BS using a single direct transmission  After a certain period of time, cluster heads are selected again through the set-up phase
  19. 19. 19 LOW-ENERGY ADAPTIVE CLUSTERING HIERARCHY (LEACH)  Merits:  Accounting for adaptive clusters and rotating cluster heads  Opportunity to implement any aggregation function at the cluster heads  Demerits:  Highly dynamic environments  Continuous updates  Mobility
  20. 20. 20 MAC PROTOCOL  During the data transmission phase, the distributed TDMA receiver oriented channel (DTROC) assignment MAC protocol is used.  Two steps of DTROC :  Channel allocation : Each node is assigned a reception channel by the BS, and channel reuse is such that collisions are avoided.  Channel scheduling : The node schedules transmission slots for all its neighbors and broadcasts the schedule. This enables collision-free transmission and saves energy, as nodes can turn off when they are not involved on a send/receive operation.
  21. 21. THERE ARE THREE TYPES OF MAC PROTOCOLS  Fixed-allocation  Demand-based  Contention-based 21
  22. 22. 22  Fixed-allocation MAC protocol  Share the common medium through a predetermined assignment.  It is suitable for sensor network that continuously monitor and generate deterministic data traffic  Provide a bounded delay for each node  However, in the case of bursty traffic, where the channel requirements of each node may vary over time, it may lead to inefficient usage of the channel.
  23. 23. 23  Demand-based MAC protocol  Used in such cases, where the channel is allocated according to the demand of the node  Variable rate traffic can be efficiently transmitted  Require the additional overhead of a reservation process  Contention-based MAC protocol  Random-access-based contention for the channel when packets need to be transmitted  Suitable for bursty traffic  Collisions and no delay guarantees, are not suitable for delay- sensitive or real-time traffic
  24. 24. 24 HYBRID TDMA/FDMA  A pure TDMA scheme minimize the time for which a node has to be kept on, but the associated time synchronization cost are very high.  A pure FDMA scheme allots the minimum required bandwidth for each connection  If the transmitter consumes more power, a TDMA scheme is favored, since it can be switch off in idle slots to save power.  If the receiver consumes greater power, a FDMA scheme is favored, because the receiver need not expend power for time synchronization.
  25. 25. NETWORK LAYER 25
  26. 26. APPLICATIONS OF LPWSN  Area monitoring  Health care monitoring  Air pollution monitoring  Forest fire detection  Landslide detection  Water quality monitoring  Natural disaster prevention  Industrial monitoring 26
  27. 27. 27  Facility management  Intrusion detection into industrial sites  Control of leakages in chemical plants, …  Machine surveillance and preventive maintenance  Embed sensing/control functions into places no cable has gone before  E.g., tire pressure monitoring  Precision agriculture  Bring out fertilizer/pesticides/irrigation only where needed  Medicine and health care  Post-operative or intensive care  Long-term surveillance of chronically ill patients or the elderly
  28. 28. CHALLENGES  Hardware : 1. Low cost 2. Tiny sensors 3. Lifetime maximization 4. Robustness and fault tolerance 5. Self-configuration  Software : 1. Operating systems 2. Security 3. Mobility 28
  29. 29. ADVANTAGES OF A WSN  Avoids a lot of wiring  Can accommodate new devices at any time  Flexible to go through physical partitions  It can be accessed through a centralized monitor  Infrastructure 29
  30. 30. DISADVANTAGES OF WSN  Easy for hackers to hack a network  Comparatively low speed of communication  Gets distracted by various elements  Costly at large  Life of nodes  Energy life 30
  31. 31. FUTURE SCOPE  More research work needs to be done in future.  Needs to be implemented in a wireless sensor network with mobile nodes.  The effects of very large node densities need to be investigated.  The feasibility of using the clustering technique and data aggregation needs to be tested in the same wireless sensor network. 31
  32. 32. FUTURE SCOPE 32
  33. 33. 33 FUTURE OF WSN SMART HOME / SMART OFFICE  Sensors controlling appliances and electrical devices in the house.  Better lighting and heating in office buildings.  The Pentagon building has used sensors extensively.
  34. 34. FUTURE SCOPE 34 Intelligent transport, industry and society, smart utilities Connected Consumer Electronics  Development of a TDMA/CSMA hybrid MAC  TinyOS currently has a CSMA MAC  Hope to improve throughput by employing TDMA  Time is divided into transmission periods and contention perio  Nodes will contend with each other to join “the transmission group” during the contention period.  Nodes in the transmission group will be allocated a time-slot in the transmission period.  Development of data storage engine optimized for fast retrieval
  35. 35. CONCLUSION This presentation shows all the techniques that are used for wireless sensor network for low power consumption , for example MAC protocol, LEACH, Network layer, ect. Most of the research on energy efficient controlled access protocol has come at a cost of control packets overhead. By investigating this research area further, an enhanced energy efficiency protocol may be developed that can revolutionise WSN’s power consumption. There are some another protocols which can be used for less energy consumption like CDMA,FDMA,TDMA. 35
  36. 36. REFERENCES  www.wikipedia.org  http://stakeholders.ofcom.org.uk/binaries/research/tec hnology-research/wsn2.pdf  http://www.researchgate.net/publication/228695105_S ervice- 36
  37. 37. 37