presentation_kalyan.pptsensor network

7/28/2019 presentation_kalyan.pptSensor Network

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CLUSTERING IN WIRELESS SENSOR

NETWORKS

BY

KALYAN SASIDHAR


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RESEARCH PROBLEM

Understanding existing clustering algorithms and finding the problems

stated and addressed

Compare the pros and cons of each algorithm

Simulate algorithms and compare performance with and without clustering

mechanism


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INTRODUCTION TO CLUSTERING Grouping of similar objects or sensors in our context

distance or proximity

Logical organizing

Topology control approach

Load balancing, network scalability

Types of clustering

Static: local topology control

Dynamic: changing network parameters

Single hop and multi hop

Homogeneous and heterogeneous


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HEED[1]


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ADVANTAGES OF CLUSTERING

Transmit aggregated data to the data sink

reducing number of nodes taking part in transmission

Useful energy consumption

Scalability for large number of nodes

Reduces communication overhead for both single and multi hop


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LITERATURE SURVEY OF CLUSTERING ALGORITHMS HEED: A hybrid energy efficient distributed clustering approach for ad-

hoc sensor networks

MRECA: Mobility resistant efficient clustering approach for ad-hocsensor networks

Energy efficient dynamic clustering algorithm for ad-hoc sensornetworks

LEACH-Energy efficient communication protocol for WSN

EEDC-Dynamic clustering and energy efficient routing technique forWSN


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Problem statement Set of nodes, identify set of CHs that cover the entire network

Protocol distributed

Local information

One node-one cluster

Node-cluster head: single hop

CH-CH: multi hop using routing protocol


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HEED

Assumptions

Sensor quasi-stationary

Links are symmetric

Energy consumption non-uniform for all nodes

Nodes-location unaware

Processing and communication capability-similar


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Algorithm:

Cluster head selection hybrid of residual energy (primary) and communication cost (secondary)

such as node proximity

Number of rounds of iterations

Tentative CHs formed

Final CH until CHprob=1

Same or different power levels used for intra cluster communication


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Pros:

Balanced clusters

Low message overhead

Uniform & non-uniform node distribution

Inter cluster communication explained

Out performs generic clustering protocols on various factors

Cons:

Repeated iterations complex algorithm

Decrease of residual energy smaller probability

number of iterations increased

Nodes with high residual energy one region of a networkFuture work:

Only two level hierarchy provided but can be extended to multilevel hierarchy


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MRECAAssumptions:

Sensor quasi-stationary

Nodes-location unaware

Every node as source and server

Algorithm:

Mobility resistant clustering approach

Deterministic time without iterations

Computed score value used to compute delay

Delay used CH announcement

Node mobility

Local maintenance performed instead of re-clustering


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Pros Clusters generated as node speed increased

Only one iteration against repeated iterations in HEED

Each node one message

saving on message transmission better energy efficiency

Robust against synchronization errors

Can be used for environmental monitoring and battlefield

applications

Cons

Inter cluster communication not explained

CH rotation mentioned but not explained how


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Future work Extensive simulations on large scale

networks with elaborate power models,

Extensions to k-hop clusters and integration

of clustering with network applications


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EEDCAssumption: Two tier hierarchy network

Routing limited to CHs route set up cost minimized

Sensors clustered

Algorithm: Active node estimation and optimum probability of becoming cluster head

Received Signal power

Cluster formation

CH with a certain probability by wining a competition with neighbors

Data collection

Node-CH using MAC protocol-p-persistent CSMA

Data delivery CH-BS-multi hop routing protocol


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Pros

Number of clusters and CH-Dynamic

Energy dissipation-even distribution

Prolong network lifetime

most efficient for large-scale sensor network

Intra and inter cluster communication explained

Future work

Further investigating the applicability of the proposed clustering

technique and routing algorithm to more general wireless sensor

networks.


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LEACHAssumptions:

Fixed and remote base station

Nodes homogeneous and energy constrained

Radio channel is symmetric

EA-EB=EB-EA

Sensing rate for all sensors fixed


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Algorithm

CH position rotated among the nodes

energy load distributed .

Number of active nodes in the network and the optimal number of clusters

assumed a priori

Nodes join a target number of CHs

Node-CH communication-TDMA


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Pros

Incorporates data fusion into routing protocols

Amount of information to base station reduced

4-8 times effective over direct communication in prolonging network

lifetime

Grid like area

Cons

Only single hop clusters formed

Might lead to large number of clusters

No discussion on optimal CH selection

All CHs should directly transmit to the data sink


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DYNAMIC CLUSTER

Energy efficiency distributed:

CH selection-both residual energy and PT

Number of nodes-network size and PT

CH -center of the cluster

Rotating CH to average power consumption

Breaking clusters and reforming

compensate for differences of power consumption in different areas

Unique route

Only CH with lowest ID and high residual energy

What is only one CH is present and that CH as low residual energy?


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Pros

Reduce flooding in route discovery

Avoid duplicate data transmission

Cons

Inter cluster communication not explained

Number of iterations needed for CH selection and cluster

formation not mentioned


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CONCLUSIONS

Problem statement seems to be unique

Reduce energy consumption

Prolong network lifetime

Form set of clusters from a set of nodes

Cluster the whole network with the selected CH

Rotate CHs for energy distribution

Algorithms differ in CH selection and cluster formation

Some address intra and inter cluster communication

Some address real world applications


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REFERENCES

[1]. A hybrid energy efficient distributed clusteringapproach for ad-hoc sensor networks

presentation_kalyan.pptsensor network

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