SlideShare a Scribd company logo
By:
Pulkit Chhabra
10103644
Topics for discussion
 Introduction
 Sensor network
 Architecture of sensor network.
 Applications of sensor network.
 Challenges of sensor network.
 Cuts in sensor networks.
 Detection of cuts.
 Distributed cut detection algorithm.
 Conclusion.
 Future aspects.
 References.
Sensor Network:
It is a group of specialized transducers with a
communication infrastructure intended to monitor
and record conditions at diverse location, it may be
temperature, pressure humidity wind direction and
speed etc…
It consists of multiple detection station called
nodes, which is small, lightweight and portable.
Contd…
Contd…
Architecture of WSNs
 Transducer generates electrical signals.
 Microcomputer processes and stores
Sensor output.
 Transceiver receives the
commands from central
computer, transmits data
to that computer.
 Power from battery.
Applications
 Industrial monitoring.
 Machine health monitoring.
 Data logging.
 Industrial sense and control applications.
 Automated and smart homes.
monitoring the activities performed in a smart
home is achieved using wireless sensors embedded
within everyday objects forming a sensor network.
 Medical device monitoring.
Contd…
 Monitoring of weather conditions.
 Air traffic control.
 Robot control.
 Air pollution monitoring.
 Forest fire detection.
 Natural disaster prevention.
Challenges
 One of the challenge in the successful use of WSNs
come from limited energy of the individual sensor
nodes.
 WSNs consist of large number of small, low cost
sensor nodes distributed over large area.
 WSNs have emerged as a promising new technology
to monitor large regions.
 Node failure is expected to be quite common. this is
true for sensor networks deployed in harsh and
dangerous fields such as forest fire monitoring and in
defense applications.
Cuts in sensor networks
 WSNs can get separated into multiple connected
components due to failure of some of its nodes, which
is called “cut”.
 So here we consider the problem of detecting cuts.
 Two nodes are said to be disconnected if there is no
path between them.
Contd…
Contd…
 In the figure, filled circles represents active nodes and
unfilled circles represent failed node.
 Solid lines represents the edges, and dashed lines
represent the edges that existed before the failure of
node.
 the hole in (d) is indistinguishable from the cut in (b)
to nodes that lie outside the region R
Detection of cuts
 Nodes that detect the occurrence and approximate the
locations of the cuts can then alert the source node or base
station.
 If the node were able to detect the occurrence of cut it could
simply wait for the network to be repaired and eventually
reconnected, which saves on-board energy of multiple nodes
and prolongs their lives.
 The ability to detect cuts by both the disconnected node and
source node will lead to increase in the operational lifetime
of the network as a whole.
Distributed cut detection algorithm
 This algorithm allows each node to detect
DOS(Disconnection frOm Source) events and subset of node
to detect CCOS(connected but cut occurred somewhere)
events.
 The algorithm is distributed and asynchronous.
 It involves only local communication between neighboring
nodes and is robust to temporary communication failure
between node pairs.
 A key component of the DCD algorithm is a distributed
iterative computational step through which the nodes
compute their electrical potentials.
Distributed cut Detection
Definition and problem statement
 Time is measured with a discrete counter k=∞,…., -
1,0,1,2,…..
 We model the sensor network as a time varying graph
𝒢(𝑘) = (𝑉(k )ℰ(k)), whose node set V(k) represents the
sensor nodes active at time k and the edge set ℰ(𝑘)
consist of pairs of nodes (u,v) such that nodes u and v can
directly exchange the message between each other at
time k.
 By an active nodes we mean a nodes that has not failed
permanently .
Contid…
 All graphs considered here are undirected i.e (i,j)=(j,i).
 The neighbors of node i is the set 𝑁𝑖 of nodes connected to i
i.e. 𝑁𝑖 = {𝑗|(𝑖, 𝑗) ∈ ℰ}.
 The numbers of neighbors of i, |𝑁𝑖 𝑘 |, is called its degree,
which is denoted by di.
 A path from i to j is sequence of edges connecting i and j.
 A graph is called connected if there is a path between every
pair of nodes.
 A component Gc of the graph is maximal connected sub
graph of G.
Contid…
 A cut is formally defined as the increase of the
number of components of a graph due to the failure of
subset of nodes.
 The number of the cuts associated with a cut event is
the increase in the number of components after the
event.
Contid…
 The problem we seek to address is two fold
 First we want to enable every node to detect if it is
disconnected from source.
 Second we want to enable nodes that lie close to the cuts
but are still connected to the source.
Contid…
 The DCD algorithm is based on the following electrical
analogy.
 Imagine the wireless sensor network as an electrical circuit
where the current is injected at the source node and
extracted out of a common fictitious node that is connected
to every node of sensor network.
 Each edge is replaced by the 1 Ω resistor.
 When a cut separates certain nodes from source node, the
potential of each of those nodes becomes 0, since there is no
current injection into their components.
 The potential is computed by an iterative scheme which only
requires periodic communication among the neighboring
nodes.
Contid…
DOS detection
• When node u is disconnected from the source, we say that a
disconnected from source event has occurred for u.
• The algorithm allows each node to detect DOS events.
• The nodes use the computed potentials to detect if DOS
event have occurred .
• The approach here is if the state is close to 0 then the node is
disconnected from the source , otherwise not.
Contid…
 DOS detection part consist of steady state detection,
normalized state computation and
connection/separation detection.
Contid…
CCOS detection
 When a cut occurs in the network that does not separate a
node u from the source node, connected but a cut occurred
somewhere (CCOS) event has occurred for u.
 Detection of CCOS events by the nodes close to a cut, and
approximate location of cut means location of one or more
active nodes that lie at the boundary of cut and that are
connected to source.
Contid…
 To detect the CCOS event the algorithm uses the fact
that the potential of nodes that are connected to
source node changes after the cut and also using probe
messages.
 Probe messages that are initiated by the certain nodes
that encounter failed neighbors, and are forwarded
from one node to another node in a way that if short
path exist around a hole created by node failures, the
message will reach initiating nodes.
Contid…
 Each probe message contains the following
information:
 A unique source ID
 Source node ID S
 Destination node,
 path traversed, and
 angle traversed by probe message.
Conclusion
 The DCD algorithm we propose here enables every
node of a wireless sensor network to detect
disconnected from source event if they occur.
 Second it enables the subset of nodes that experiences
CCOS event to detect them and estimate the
approximate location of the cut in the form of a list of
active nodes that lie at the boundary of the cut/hole.
Future Aspect
 Application of DCD algorithm to detect the node
separation and reconnection to the source in mobile
networks.
references
 http:// www.liveieeeprojects.com
 http://www.ijsrp.org/research-paper-1212/ijsrp-p1203.pd
 http://www.faculty.cs.tamu.edu/stoleru/papers/prabir12c
ut.pdf - United States
 www.cs.ucsb.edu/~suri/psdir/sentinel.pdf
 www.slideshare.net/.../cut-detection-in-wireless-sensor-
networks
 http://en.wikipedia.org/wiki/Wireless_sensor_network
THANK YOU

More Related Content

What's hot

Memristor -The fourth fundumental circuit element
Memristor -The fourth fundumental circuit elementMemristor -The fourth fundumental circuit element
Memristor -The fourth fundumental circuit element
Helal Uddin Mullah
 
memristor
memristormemristor
memristor
jithoot
 
TRACK E: Memristors: Not Just Memory/ Shahar Kvatinsky
TRACK E: Memristors: Not Just Memory/ Shahar KvatinskyTRACK E: Memristors: Not Just Memory/ Shahar Kvatinsky
TRACK E: Memristors: Not Just Memory/ Shahar Kvatinsky
chiportal
 
Energy efficient protocol in wsn WITH ACO
Energy efficient protocol in wsn WITH ACOEnergy efficient protocol in wsn WITH ACO
Energy efficient protocol in wsn WITH ACO
Neelam Choudhary
 
Memristor report
Memristor reportMemristor report
Memristor report
Akash Garg
 

What's hot (19)

IJCER (www.ijceronline.com) International Journal of computational Engineeri...
 IJCER (www.ijceronline.com) International Journal of computational Engineeri... IJCER (www.ijceronline.com) International Journal of computational Engineeri...
IJCER (www.ijceronline.com) International Journal of computational Engineeri...
 
Cube2012 Submission 359
Cube2012 Submission 359Cube2012 Submission 359
Cube2012 Submission 359
 
Memristors
MemristorsMemristors
Memristors
 
memristor
memristormemristor
memristor
 
Memristor overview
Memristor overviewMemristor overview
Memristor overview
 
Ii2414621475
Ii2414621475Ii2414621475
Ii2414621475
 
Memristor
MemristorMemristor
Memristor
 
Memristors
MemristorsMemristors
Memristors
 
Bi24385389
Bi24385389Bi24385389
Bi24385389
 
Memristor
MemristorMemristor
Memristor
 
Memristor -The fourth fundumental circuit element
Memristor -The fourth fundumental circuit elementMemristor -The fourth fundumental circuit element
Memristor -The fourth fundumental circuit element
 
memristor
memristormemristor
memristor
 
Proposals for Memristor Crossbar Design and Applications
Proposals for Memristor Crossbar Design and ApplicationsProposals for Memristor Crossbar Design and Applications
Proposals for Memristor Crossbar Design and Applications
 
TRACK E: Memristors: Not Just Memory/ Shahar Kvatinsky
TRACK E: Memristors: Not Just Memory/ Shahar KvatinskyTRACK E: Memristors: Not Just Memory/ Shahar Kvatinsky
TRACK E: Memristors: Not Just Memory/ Shahar Kvatinsky
 
Mythology of the Memristor
Mythology of the MemristorMythology of the Memristor
Mythology of the Memristor
 
Energy efficient protocol in wsn WITH ACO
Energy efficient protocol in wsn WITH ACOEnergy efficient protocol in wsn WITH ACO
Energy efficient protocol in wsn WITH ACO
 
Memristor report
Memristor reportMemristor report
Memristor report
 
Memristor ppt
Memristor pptMemristor ppt
Memristor ppt
 
Indoor Localization in Wireless Sensor Networks
Indoor Localization in Wireless Sensor NetworksIndoor Localization in Wireless Sensor Networks
Indoor Localization in Wireless Sensor Networks
 

Viewers also liked

Iii b.tech. ii sem r09 regular april 2013
Iii b.tech. ii sem r09 regular april 2013Iii b.tech. ii sem r09 regular april 2013
Iii b.tech. ii sem r09 regular april 2013
prasadmvreddy
 
B tech ii year i (r07) semester supplementary
B tech ii year i (r07) semester supplementaryB tech ii year i (r07) semester supplementary
B tech ii year i (r07) semester supplementary
prasadmvreddy
 
A szemelyes markaepites_eloadas_pja
A szemelyes markaepites_eloadas_pjaA szemelyes markaepites_eloadas_pja
A szemelyes markaepites_eloadas_pja
Palluch József
 
B tech ii year i semester regular examinations november 2011 results
B tech ii year i semester regular examinations november 2011 resultsB tech ii year i semester regular examinations november 2011 results
B tech ii year i semester regular examinations november 2011 results
prasadmvreddy
 
B tech iv year i (r07) semester supplementary
B tech iv year i (r07) semester supplementaryB tech iv year i (r07) semester supplementary
B tech iv year i (r07) semester supplementary
prasadmvreddy
 
B tech ii year ii (r07) semester supplementary
B tech ii year ii (r07) semester supplementaryB tech ii year ii (r07) semester supplementary
B tech ii year ii (r07) semester supplementary
prasadmvreddy
 
B tech iii year i (r07) semester supplementary
B tech iii year i (r07) semester supplementaryB tech iii year i (r07) semester supplementary
B tech iii year i (r07) semester supplementary
prasadmvreddy
 
B.Tech I Year (R09) Regular , Supplementary June 2013
B.Tech I Year (R09) Regular , Supplementary June 2013B.Tech I Year (R09) Regular , Supplementary June 2013
B.Tech I Year (R09) Regular , Supplementary June 2013
prasadmvreddy
 

Viewers also liked (8)

Iii b.tech. ii sem r09 regular april 2013
Iii b.tech. ii sem r09 regular april 2013Iii b.tech. ii sem r09 regular april 2013
Iii b.tech. ii sem r09 regular april 2013
 
B tech ii year i (r07) semester supplementary
B tech ii year i (r07) semester supplementaryB tech ii year i (r07) semester supplementary
B tech ii year i (r07) semester supplementary
 
A szemelyes markaepites_eloadas_pja
A szemelyes markaepites_eloadas_pjaA szemelyes markaepites_eloadas_pja
A szemelyes markaepites_eloadas_pja
 
B tech ii year i semester regular examinations november 2011 results
B tech ii year i semester regular examinations november 2011 resultsB tech ii year i semester regular examinations november 2011 results
B tech ii year i semester regular examinations november 2011 results
 
B tech iv year i (r07) semester supplementary
B tech iv year i (r07) semester supplementaryB tech iv year i (r07) semester supplementary
B tech iv year i (r07) semester supplementary
 
B tech ii year ii (r07) semester supplementary
B tech ii year ii (r07) semester supplementaryB tech ii year ii (r07) semester supplementary
B tech ii year ii (r07) semester supplementary
 
B tech iii year i (r07) semester supplementary
B tech iii year i (r07) semester supplementaryB tech iii year i (r07) semester supplementary
B tech iii year i (r07) semester supplementary
 
B.Tech I Year (R09) Regular , Supplementary June 2013
B.Tech I Year (R09) Regular , Supplementary June 2013B.Tech I Year (R09) Regular , Supplementary June 2013
B.Tech I Year (R09) Regular , Supplementary June 2013
 

Similar to Pulkit 10103644

Similar to Pulkit 10103644 (20)

Cut detection
Cut detectionCut detection
Cut detection
 
Cut Detection in Wireless Sensor Network
Cut Detection in Wireless Sensor NetworkCut Detection in Wireless Sensor Network
Cut Detection in Wireless Sensor Network
 
Hack Recognition In Wireless Sensor Network
Hack Recognition In Wireless Sensor NetworkHack Recognition In Wireless Sensor Network
Hack Recognition In Wireless Sensor Network
 
A Distributed Cut Detection Method for Wireless Sensor Networks
A Distributed Cut Detection Method for Wireless Sensor NetworksA Distributed Cut Detection Method for Wireless Sensor Networks
A Distributed Cut Detection Method for Wireless Sensor Networks
 
Ijetr012022
Ijetr012022Ijetr012022
Ijetr012022
 
Delay efficient broadcast scheduling for critical event monitoring in wireles...
Delay efficient broadcast scheduling for critical event monitoring in wireles...Delay efficient broadcast scheduling for critical event monitoring in wireles...
Delay efficient broadcast scheduling for critical event monitoring in wireles...
 
Delay efficient broadcast scheduling for critical event monitoring in wireles...
Delay efficient broadcast scheduling for critical event monitoring in wireles...Delay efficient broadcast scheduling for critical event monitoring in wireles...
Delay efficient broadcast scheduling for critical event monitoring in wireles...
 
Modified Coverage Hole Detection Algorithm for Distributed WSNs
Modified Coverage Hole Detection Algorithm for Distributed WSNsModified Coverage Hole Detection Algorithm for Distributed WSNs
Modified Coverage Hole Detection Algorithm for Distributed WSNs
 
Analysis and reactive measures on the blackhole attack
Analysis and reactive measures on the blackhole attackAnalysis and reactive measures on the blackhole attack
Analysis and reactive measures on the blackhole attack
 
Ar03302620266
Ar03302620266Ar03302620266
Ar03302620266
 
D0952126
D0952126D0952126
D0952126
 
Sensor net
Sensor netSensor net
Sensor net
 
Node Deployment in Homogeneous and Heterogeneous Wireless Sensor Network
Node Deployment in Homogeneous and Heterogeneous Wireless Sensor NetworkNode Deployment in Homogeneous and Heterogeneous Wireless Sensor Network
Node Deployment in Homogeneous and Heterogeneous Wireless Sensor Network
 
2512ijcsea02
2512ijcsea022512ijcsea02
2512ijcsea02
 
Cluster Head and RREQ based Detection and Prevention of Gray hole and Denial ...
Cluster Head and RREQ based Detection and Prevention of Gray hole and Denial ...Cluster Head and RREQ based Detection and Prevention of Gray hole and Denial ...
Cluster Head and RREQ based Detection and Prevention of Gray hole and Denial ...
 
Multi-Robot Sensor Relocation to Enhance Connectivity in a WSN
Multi-Robot Sensor Relocation to Enhance Connectivity in a WSNMulti-Robot Sensor Relocation to Enhance Connectivity in a WSN
Multi-Robot Sensor Relocation to Enhance Connectivity in a WSN
 
MULTI-ROBOT SENSOR RELOCATION TO ENHANCE CONNECTIVITY IN A WSN
MULTI-ROBOT SENSOR RELOCATION TO ENHANCE CONNECTIVITY IN A WSN MULTI-ROBOT SENSOR RELOCATION TO ENHANCE CONNECTIVITY IN A WSN
MULTI-ROBOT SENSOR RELOCATION TO ENHANCE CONNECTIVITY IN A WSN
 
Multi-Robot Sensor Relocation to Enhance Connectivity in a WSN
Multi-Robot Sensor Relocation to Enhance Connectivity in a WSNMulti-Robot Sensor Relocation to Enhance Connectivity in a WSN
Multi-Robot Sensor Relocation to Enhance Connectivity in a WSN
 
Intrusion detection in wireless sensor network
Intrusion detection in wireless sensor networkIntrusion detection in wireless sensor network
Intrusion detection in wireless sensor network
 
Spatial Correlation Based Medium Access Control Protocol Using DSR & AODV Rou...
Spatial Correlation Based Medium Access Control Protocol Using DSR & AODV Rou...Spatial Correlation Based Medium Access Control Protocol Using DSR & AODV Rou...
Spatial Correlation Based Medium Access Control Protocol Using DSR & AODV Rou...
 

Recently uploaded

ONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdf
ONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdfONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdf
ONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdf
Kamal Acharya
 
Laundry management system project report.pdf
Laundry management system project report.pdfLaundry management system project report.pdf
Laundry management system project report.pdf
Kamal Acharya
 
DR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdf
DR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdfDR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdf
DR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdf
DrGurudutt
 
Paint shop management system project report.pdf
Paint shop management system project report.pdfPaint shop management system project report.pdf
Paint shop management system project report.pdf
Kamal Acharya
 
grop material handling.pdf and resarch ethics tth
grop material handling.pdf and resarch ethics tthgrop material handling.pdf and resarch ethics tth
grop material handling.pdf and resarch ethics tth
AmanyaSylus
 
Fruit shop management system project report.pdf
Fruit shop management system project report.pdfFruit shop management system project report.pdf
Fruit shop management system project report.pdf
Kamal Acharya
 

Recently uploaded (20)

Event Management System Vb Net Project Report.pdf
Event Management System Vb Net  Project Report.pdfEvent Management System Vb Net  Project Report.pdf
Event Management System Vb Net Project Report.pdf
 
NO1 Pandit Black Magic Removal in Uk kala jadu Specialist kala jadu for Love ...
NO1 Pandit Black Magic Removal in Uk kala jadu Specialist kala jadu for Love ...NO1 Pandit Black Magic Removal in Uk kala jadu Specialist kala jadu for Love ...
NO1 Pandit Black Magic Removal in Uk kala jadu Specialist kala jadu for Love ...
 
ONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdf
ONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdfONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdf
ONLINE VEHICLE RENTAL SYSTEM PROJECT REPORT.pdf
 
BRAKING SYSTEM IN INDIAN RAILWAY AutoCAD DRAWING
BRAKING SYSTEM IN INDIAN RAILWAY AutoCAD DRAWINGBRAKING SYSTEM IN INDIAN RAILWAY AutoCAD DRAWING
BRAKING SYSTEM IN INDIAN RAILWAY AutoCAD DRAWING
 
Laundry management system project report.pdf
Laundry management system project report.pdfLaundry management system project report.pdf
Laundry management system project report.pdf
 
DR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdf
DR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdfDR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdf
DR PROF ING GURUDUTT SAHNI WIKIPEDIA.pdf
 
ONLINE CAR SERVICING SYSTEM PROJECT REPORT.pdf
ONLINE CAR SERVICING SYSTEM PROJECT REPORT.pdfONLINE CAR SERVICING SYSTEM PROJECT REPORT.pdf
ONLINE CAR SERVICING SYSTEM PROJECT REPORT.pdf
 
2024 DevOps Pro Europe - Growing at the edge
2024 DevOps Pro Europe - Growing at the edge2024 DevOps Pro Europe - Growing at the edge
2024 DevOps Pro Europe - Growing at the edge
 
A case study of cinema management system project report..pdf
A case study of cinema management system project report..pdfA case study of cinema management system project report..pdf
A case study of cinema management system project report..pdf
 
Introduction to Machine Learning Unit-5 Notes for II-II Mechanical Engineering
Introduction to Machine Learning Unit-5 Notes for II-II Mechanical EngineeringIntroduction to Machine Learning Unit-5 Notes for II-II Mechanical Engineering
Introduction to Machine Learning Unit-5 Notes for II-II Mechanical Engineering
 
Quality defects in TMT Bars, Possible causes and Potential Solutions.
Quality defects in TMT Bars, Possible causes and Potential Solutions.Quality defects in TMT Bars, Possible causes and Potential Solutions.
Quality defects in TMT Bars, Possible causes and Potential Solutions.
 
RESORT MANAGEMENT AND RESERVATION SYSTEM PROJECT REPORT.pdf
RESORT MANAGEMENT AND RESERVATION SYSTEM PROJECT REPORT.pdfRESORT MANAGEMENT AND RESERVATION SYSTEM PROJECT REPORT.pdf
RESORT MANAGEMENT AND RESERVATION SYSTEM PROJECT REPORT.pdf
 
KIT-601 Lecture Notes-UNIT-3.pdf Mining Data Stream
KIT-601 Lecture Notes-UNIT-3.pdf Mining Data StreamKIT-601 Lecture Notes-UNIT-3.pdf Mining Data Stream
KIT-601 Lecture Notes-UNIT-3.pdf Mining Data Stream
 
Paint shop management system project report.pdf
Paint shop management system project report.pdfPaint shop management system project report.pdf
Paint shop management system project report.pdf
 
Electrostatic field in a coaxial transmission line
Electrostatic field in a coaxial transmission lineElectrostatic field in a coaxial transmission line
Electrostatic field in a coaxial transmission line
 
İTÜ CAD and Reverse Engineering Workshop
İTÜ CAD and Reverse Engineering WorkshopİTÜ CAD and Reverse Engineering Workshop
İTÜ CAD and Reverse Engineering Workshop
 
Peek implant persentation - Copy (1).pdf
Peek implant persentation - Copy (1).pdfPeek implant persentation - Copy (1).pdf
Peek implant persentation - Copy (1).pdf
 
Maestro Scripting Language CNC programacion
Maestro Scripting Language CNC programacionMaestro Scripting Language CNC programacion
Maestro Scripting Language CNC programacion
 
grop material handling.pdf and resarch ethics tth
grop material handling.pdf and resarch ethics tthgrop material handling.pdf and resarch ethics tth
grop material handling.pdf and resarch ethics tth
 
Fruit shop management system project report.pdf
Fruit shop management system project report.pdfFruit shop management system project report.pdf
Fruit shop management system project report.pdf
 

Pulkit 10103644

  • 2. Topics for discussion  Introduction  Sensor network  Architecture of sensor network.  Applications of sensor network.  Challenges of sensor network.  Cuts in sensor networks.  Detection of cuts.  Distributed cut detection algorithm.  Conclusion.  Future aspects.  References.
  • 3. Sensor Network: It is a group of specialized transducers with a communication infrastructure intended to monitor and record conditions at diverse location, it may be temperature, pressure humidity wind direction and speed etc… It consists of multiple detection station called nodes, which is small, lightweight and portable.
  • 6. Architecture of WSNs  Transducer generates electrical signals.  Microcomputer processes and stores Sensor output.  Transceiver receives the commands from central computer, transmits data to that computer.  Power from battery.
  • 7. Applications  Industrial monitoring.  Machine health monitoring.  Data logging.  Industrial sense and control applications.  Automated and smart homes. monitoring the activities performed in a smart home is achieved using wireless sensors embedded within everyday objects forming a sensor network.  Medical device monitoring.
  • 8. Contd…  Monitoring of weather conditions.  Air traffic control.  Robot control.  Air pollution monitoring.  Forest fire detection.  Natural disaster prevention.
  • 9. Challenges  One of the challenge in the successful use of WSNs come from limited energy of the individual sensor nodes.  WSNs consist of large number of small, low cost sensor nodes distributed over large area.  WSNs have emerged as a promising new technology to monitor large regions.  Node failure is expected to be quite common. this is true for sensor networks deployed in harsh and dangerous fields such as forest fire monitoring and in defense applications.
  • 10. Cuts in sensor networks  WSNs can get separated into multiple connected components due to failure of some of its nodes, which is called “cut”.  So here we consider the problem of detecting cuts.  Two nodes are said to be disconnected if there is no path between them.
  • 12. Contd…  In the figure, filled circles represents active nodes and unfilled circles represent failed node.  Solid lines represents the edges, and dashed lines represent the edges that existed before the failure of node.  the hole in (d) is indistinguishable from the cut in (b) to nodes that lie outside the region R
  • 13. Detection of cuts  Nodes that detect the occurrence and approximate the locations of the cuts can then alert the source node or base station.  If the node were able to detect the occurrence of cut it could simply wait for the network to be repaired and eventually reconnected, which saves on-board energy of multiple nodes and prolongs their lives.  The ability to detect cuts by both the disconnected node and source node will lead to increase in the operational lifetime of the network as a whole.
  • 14. Distributed cut detection algorithm  This algorithm allows each node to detect DOS(Disconnection frOm Source) events and subset of node to detect CCOS(connected but cut occurred somewhere) events.  The algorithm is distributed and asynchronous.  It involves only local communication between neighboring nodes and is robust to temporary communication failure between node pairs.  A key component of the DCD algorithm is a distributed iterative computational step through which the nodes compute their electrical potentials.
  • 15. Distributed cut Detection Definition and problem statement  Time is measured with a discrete counter k=∞,…., - 1,0,1,2,…..  We model the sensor network as a time varying graph 𝒢(𝑘) = (𝑉(k )ℰ(k)), whose node set V(k) represents the sensor nodes active at time k and the edge set ℰ(𝑘) consist of pairs of nodes (u,v) such that nodes u and v can directly exchange the message between each other at time k.  By an active nodes we mean a nodes that has not failed permanently .
  • 16. Contid…  All graphs considered here are undirected i.e (i,j)=(j,i).  The neighbors of node i is the set 𝑁𝑖 of nodes connected to i i.e. 𝑁𝑖 = {𝑗|(𝑖, 𝑗) ∈ ℰ}.  The numbers of neighbors of i, |𝑁𝑖 𝑘 |, is called its degree, which is denoted by di.  A path from i to j is sequence of edges connecting i and j.  A graph is called connected if there is a path between every pair of nodes.  A component Gc of the graph is maximal connected sub graph of G.
  • 17. Contid…  A cut is formally defined as the increase of the number of components of a graph due to the failure of subset of nodes.  The number of the cuts associated with a cut event is the increase in the number of components after the event.
  • 18. Contid…  The problem we seek to address is two fold  First we want to enable every node to detect if it is disconnected from source.  Second we want to enable nodes that lie close to the cuts but are still connected to the source.
  • 19. Contid…  The DCD algorithm is based on the following electrical analogy.  Imagine the wireless sensor network as an electrical circuit where the current is injected at the source node and extracted out of a common fictitious node that is connected to every node of sensor network.  Each edge is replaced by the 1 Ω resistor.  When a cut separates certain nodes from source node, the potential of each of those nodes becomes 0, since there is no current injection into their components.  The potential is computed by an iterative scheme which only requires periodic communication among the neighboring nodes.
  • 20. Contid… DOS detection • When node u is disconnected from the source, we say that a disconnected from source event has occurred for u. • The algorithm allows each node to detect DOS events. • The nodes use the computed potentials to detect if DOS event have occurred . • The approach here is if the state is close to 0 then the node is disconnected from the source , otherwise not.
  • 21. Contid…  DOS detection part consist of steady state detection, normalized state computation and connection/separation detection.
  • 22. Contid… CCOS detection  When a cut occurs in the network that does not separate a node u from the source node, connected but a cut occurred somewhere (CCOS) event has occurred for u.  Detection of CCOS events by the nodes close to a cut, and approximate location of cut means location of one or more active nodes that lie at the boundary of cut and that are connected to source.
  • 23. Contid…  To detect the CCOS event the algorithm uses the fact that the potential of nodes that are connected to source node changes after the cut and also using probe messages.  Probe messages that are initiated by the certain nodes that encounter failed neighbors, and are forwarded from one node to another node in a way that if short path exist around a hole created by node failures, the message will reach initiating nodes.
  • 24. Contid…  Each probe message contains the following information:  A unique source ID  Source node ID S  Destination node,  path traversed, and  angle traversed by probe message.
  • 25. Conclusion  The DCD algorithm we propose here enables every node of a wireless sensor network to detect disconnected from source event if they occur.  Second it enables the subset of nodes that experiences CCOS event to detect them and estimate the approximate location of the cut in the form of a list of active nodes that lie at the boundary of the cut/hole.
  • 26. Future Aspect  Application of DCD algorithm to detect the node separation and reconnection to the source in mobile networks.
  • 27. references  http:// www.liveieeeprojects.com  http://www.ijsrp.org/research-paper-1212/ijsrp-p1203.pd  http://www.faculty.cs.tamu.edu/stoleru/papers/prabir12c ut.pdf - United States  www.cs.ucsb.edu/~suri/psdir/sentinel.pdf  www.slideshare.net/.../cut-detection-in-wireless-sensor- networks  http://en.wikipedia.org/wiki/Wireless_sensor_network