This document provides an outline and overview of a presentation titled "Fault Tolerance in Wireless Sensor Networks Using Constrained Delaunay Triangulation". The presentation discusses using Constrained Delaunay Triangulation as a coverage strategy to provide fault tolerance, event reporting, and energy efficiency in wireless sensor networks. It outlines the proposed work, which includes deploying sensors, distributed greedy algorithm for coverage, Constrained Delaunay Triangulation algorithm, and selection of backup nodes. Simulation results are presented comparing the proposed approach to traditional approaches.
Fault tolerance in wireless sensor networks by Constrained Delaunay Triangulation Coverage Strategy
1. A Presentation on
Fault Tolerance in Wireless Sensor Networks
by
Constrained Delaunay Triangulation Coverage Strategy
Under Guidance of: Presented by :-
Prof. Dr. Santosh Kumar Swain Ramnesh Dubey
Dept. of Computer science & Engg. Branch: M. Tech.(CSE)
KIIT University Roll no: 1050013
1
2. Outline
1. Introduction
2. Literature Survey
3. Motivation
4. Problem Definition
5. Objective
6. Proposed Work
7. Simulation Result
8. Comparison
9. Conclusion
10. Future Work
11. References
2
3. Introduction
Development of sensor nodes,
Advances in with sensing, data processing,
wireless and communicating
Communications components:
low cost
low dimension
low power consumption
Sensing Computing
low memory
Communication low computational power
A wireless sensor network is composed by a large number of sensor
sensing self-powered nodes.
3
4. Introduction (Contd.)
Energy Efficiency
Deployed Sensor
Coverage
network
Fault tolerant:
The system should be robust against node failure.
4
5. Literature Survey
• Coverage in WSNs:
Coverage
Fault Deployment Energy Event
Type Radii
Tolerance Strategies Efficiency Transfer
Target Area
Fixed Variable
Coverage coverage
5
7. Literature Survey (Contd.)
Coverage Strategies
Coverage Strategies
Computational
Force Based Grid Based
Geometry Based
Triangular Lattice Voronoi Diagram
Square Grid Delaunay Triangulation
Hexagonal Grid Constrained Delaunay
Triangulation
7
8. Motivation
• Coverage strategies proposed so far do not facilitate
fault tolerance and energy efficiency together.
• Sensor networks are energy constrained as they are
battery operated, but in addition to provide fault
tolerant coverage, the energy efficiency of the network
must be maintained.
• K - coverage mechanisms proposed in the literature are
not energy efficient as several sensors report
simultaneously, leading to excessive energy
consumption, congestion, and collisions in the
network.
• This reduces the quality of service and network
performance.
8
10. Objective
My objective is to enhances a fault tolerant
coverage protocol that incorporate.
• Event reporting with the help of additional
support structure and
• Energy efficiency by reducing the communication.
10
11. Proposed Work
Deployment
Coverage
Backup Coverage
Distributed Greedy Algo.
Constrained Delaunay Triangulation
Algo.
And Selection of Backup node
11
14. Proposed Work (Contd.)
Distributed Greedy Algo.
• Procedure 2-COVERAGE (S [ ])
• S [ ] is the set of sensor nodes deployed
• R is the region to be covered
• snode ← S[x] : x is randomly selected node
• while (R is not Covered) do
• dbl[i]← snode
• snode← broadcast()
• snode ←recv()
• snode ←maxBenifit()
• i ←i+1
• end while
• end procedure
14
15. Proposed Work (Contd.)
Algorithm for Constrained Delaunay
triangulation CDT
1.Construct DT, set color of each node to WHITE, and
broadcast all its 1-hop neighbor information using the
packet Neighbor_Packet.
2.Nodes having lowest id among its 2-hop neighbors set their
color to BLACK.
3. Each BLACK node chooses a set N of nodes from its 1-hop
neighbors using the following method.
(a) N = empty
(b) n1 = farthest neighbor
(c) N = N ᴜ n1
(d) for i = 2, 3,. . .
15
16. Proposed Work (Contd.)
Algorithm for Constrained Delaunay
triangulation CDT
{
ni = choose ith farthest neighbour
if ni makes more than 60 degree angle with
n1 , n2 , . . . , ni - 1
then N = N ᴜ ni
}
4. Each BLACK node add the constraint edges to the nodes in N and broadcasts these constraint
edges information using the message Constraint _Packet.
5. Each WHITE node sets its color = BROWN if it is other end of any constrained edges received
using Constraint _Packet.
6. Each BROWN node broadcasts its constraint edge information using the control packet
Constraint _Packet.
7. All WHITE and BROWN nodes remove edges connected to it which crosses constraint
edged, this information is broadcasted using Edge cross _Packet.
8. Each-BLACK node places a new edge from the WHITE nodes, from which the edge was
deleted in the previous step to from new triangles. 16
17. Proposed Work (Contd.)
Selection of Backup Nodes Algo.
• Procedure: BK SELECT (dbl [ ])
•
• dbl [ ] is the set of sensor nodes providing 2Coverage
•
• Neighbors [ ] is the set of Triangle Neighbors of each node
•
• i ←0
• while i ≠ dbl.end() do
•
• if dbl[i].area() ≡ Neighbors [ ].area() then
• backup[ j] ← dbl[i]
• PotPri[] ←nearest(Neighbors[],backup[ j])
• PotPri[] ←median(Neighbors[],backup[ j])
• i ← i+1
• end if
• end while
• while i ≠ PotPri.end() do
• if PotPri.area() ≡ Neighbors [ ].area() then
• backup[] ←PotPri[i]
• erase(PotPri[i])
• end if
• end while
• end procedure
17
20. Proposed Work (Contd.)
• Event Reporting
a. Several nodes detecting and reporting events to
common forwarder.
b. A node and its forwarder detecting the event.
c. Channel access issues.
20
22. Simulation Result
Simulation Environment
Parameter Low Power Value High Power Value
Number of nodes 50 50
Area Range (m*m) 1000 1000
Transmission range (m) 195 195
Data Packet size 512 512
Bandwidth (Kbps) 2.4 100
Transmit power (mW) 14.88 660
Receive power (mW) 12.50 395
Idle power (mW) 12.36 350
sleep power (mW) 1.4 300
22
38. Conclusion
To provide quality service by coverage strategy,
there arises a need for developing protocols to
provide.
• Fault tolerance.
• Event reporting and
• Maintain energy efficiency.
38
39. Future Work
• Better mechanisms in choosing the minimal
number of nodes for our Coverage Strategy.
• Lowering the contention in the Network.
• Low latency.
39
40. Dissertation
R.Dubey, S.K.Swain, C.P.Kashayp, R.Bera “Fault Tolerance in
Wireless Sensor Networks Using Constrained Delaunay
Triangulation”, International Conference on Electrical Engineering
and Computer Science (ICEECS), IRNet, April 2012.
• R.Dubey, S.K.Swain, N.S.Mandal, C.M.Mourya, “Constrained
Delaunay Triangulation for Wireless Sensor Networks", Elsevier Ad
Hoc Networks,2012.( Communicated)
40
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