Resilient Approach for Energy Management

on Hot Spots in WSNs

Fernando Henrique Gielow

Michele Nogueira

Aldri Luiz dos Santos

{fhgielow,michele,aldri}@inf.ufpr.br

NR2 – Federal University of Paraná

IFIP/IEEE IM2011

Dublin, May 23th, 2011

Outline

Introduction and motivation Related work CEA – Cluster-based Energy Architecture RRUCR

Definition of scopes Clustering Initial backbone creation Cluster-heads rotations Data gathering & Routes maintenance

Evaluation Conclusion

Introduction and motivation

Sensor nodes: constrained resources Low processing and storage capabilities Limited lifetime

Applications Surveillance/monitoring systems Data gathering applications

Traffic patterns

Unequal traffic distribution Data gathering applications Areas burdened with higher traffic rates

Introduction and motivation

n to n n to 1

Hot Spots There are more important nodes in the network Unequal traffic distribution

Areas burdened with higher traffic rates Mitigation through sink mobility, biased deployment, unequal clustering

Introduction and motivation

Hot Spot mitigation Sink mobility

The nodes close to the sink will change eventually

Unpractical in the majority of scenarios E.g. [Thanigaivelu and Murugan, 2009]

Biased deployment Manually deploying more nodes near the sink Unpractical in the majority of scenarios E.g. [Wu and Chen, 2006]

Unequal clustering Smaller clusters near the sink More routes to reach the sink E.g. [Chen et al, 2009]

Related work

CEA: Cluster-based Energy Architecture

Generic behavior Cluster-based Hot spot

mitigation

Intra/inter clusters energy management

Route management

The RRUCR protocol

Rotation Reactive Unequal Cluster based Routing Cluster-based multi-hop protocol for

networks with n to 1 traffic pattern Data gathering applications

Unequal clusters to mitigate hot spots

Dynamic maintenance of routes

Operations of RRUCR

Definition of scopes Clustering Initial backbone creation Cluster-heads rotations Data gathering & Routes maintenance

RRUCRDefinition of scopes

Transmission powers ordered and indexed The sink covers those powers

1

2

2

2

2

3

3

3

3

4

4

4

4

Potence index used by the sink

to cover most distant node

Potence index used by the sink to cover nearest

node

Potence index used by current

node to reach the sink

Potence index limit to this operation

RRUCRClustering

Unequal sized Hot spot mitigation(funneling of routes) Previously defined

scope power

Balanced quantity Avoids dense areas Still cover all nodes

RRUCRInitial backbone creation

Process initialized by the sink Process carried by cluster-heads

Update route and forward message once

RRUCRCluster-heads rotations

Balance internal energy consumption Prolong network lifetime Generate broken links when selecting farther nodes Force route update of the node that rotated ( )

and of the nodes which used the previous CH ( )

CHs route the data to the sink in a multi-hop way That message carries a field which indicates the

distance from the node up to the sink Used to update routes

If obligatory and a node with shorter distance found Reactive approach, with low overhead

RRUCRData gathering & Routes maintenance

EvaluationParameters

1000x1000m 700 nodes Initial energy between 0.9 and 1.1 J 1% prob. of generating 32 bytes of data at each 0.1s 5000s Radio parameters set according to Mica2 3 scenarios

Without failures With failures close to the sink With failures far from the sink

ns-2.30 simulator 35 simulations – interval of confidence of 95% Compared to UCR

Evaluation

21%17%

13%

Evaluation

Evaluation

Conclusion

Address the Hot spot impacts on WSN Less deaths close to the sink Improve network lifetime

RRUCR Balanced quantity of clusters Increased network lifetime in 21.36%, when

compared to UCR Increased data delivery rates

Work extended to a generic architecture (CEA)

Future work

Operations that check the integrity on WSN links

More complex route maintenance

A TinyOS implementation of RRUCR

Project page with more information

www.nr2.ufpr.br/~fernando/rrucr/

Source code available under LGPL ns-2.30 simulation Installation script

Email for contact: fhgielow@inf.ufpr.br

Doubts?