an energy-efficient and reliable multi-hop cluster-based wireless sensor networks

Copyright © 2010, [email protected]

An Energy-Efficient and Reliable Multi-hop Cluster-based Wireless Sensor Networks

指導教授：王國禎博士　　學生：徐逸懷

國立交通大學資訊工程研究所行動計算與寬頻網路實驗室


Outline

• Introduction• Related work• Proposed energy-efficient and reliable multi-hop cluster-based

(ERMC) WSNs• Performance evaluation

– Evaluation metrics– Simulation results

• Conclusion • References

2


Introduction (1/3)

• Wireless Sensor Networks (WSNs) are comprised of large amount of energy-constrained sensor nodes, which communicate with each other and have low processing ability

• Since it is impossible to recharge the battery of sensor nodes,

how to reduce energy consumption of sensor nodes to extend the network life time of WSNs becomes a critical issue [1]

3


Introduction (2/3)

• In hierarchical clustering protocols, each cluster consists of a

cluster head (CH) and cluster members (CM). CH is used to be a leader of a cluster which is responsible for data aggregation/fusion, sleep scheduling, etc [2]

• The nodes having higher density factor which means having more neighbors are elected as cluster head so that the energy consumption can be minimized as well as network life time can be maximized [3]

4


Introduction (3/3)

5

• After the construction of a cluster, if one node is not involved

in any cluster, which is called isolated node [1]. The isolated node may cost much more energy consumption than others because it needs to find the path to relay data for the sink on its own

• Once the WSN structure is well-established, the inter-cluster communication between CHs is necessary. In other words, CHs use multi-hop communication with each other through its CM inside the cluster


Related work

• Comparison of proposed ERMC with other protocols

6

ApproachTransmission power

Cluster formation factor

Multi-hop routing factor

Mobile agent used

Isolated node

Energy efficiency

CBCDACP[3] Varied

Node density and minimum

distance between all nodes with

CHs

None No No Low

EECP[1] Varied Energy level None No Yes Medium

BOCH[4] Fixed None

Cluster degree

and minimum hopcount

No No Medium

Proposed ERMC

Fixed

Node density and minimum

distance between CHs with their

neighbors

Cluster degree, residual energy,

and maximal residual energy

Yes Yes High


Proposed ERMC protocol (1/16)

• Network architecture [3]

The sink is fixed and located far away from the sensor nodes The sink knows node location, node identity (ID), and initial

energy of each node The sensor nodes are energy constrained with a uniform initial

energy allocation The nodes have fixed transmitted power Each node senses the data at a fix rate and always has data to

send to the sink All nodes are capable of moving

7


Proposed ERMC protocol (2/16)

• The operation of ERMC is divided into rounds

• Each round consists of four phases, which are cluster formation phase, isolated node assisted phase, steady phase, and Cross-CHs route construction phase

8


Proposed EMC-MAC protocol (3/16)

• Cluster formation phase

the sink selects cluster head candidates from a set of alive nodes whose energy level is higher than the average energy level

Sink selects CHs from the candidate set depending on which have higher sensor density that is the number of closest neighbors

For calculating the density of each CH candidate, we use the following equation

Where X is any alive node, 1…P is a set of candidate nodes, and is the absolute distance between X and i

9

))(...(2)(1)min( )( PdistdistdistXNeighbor

(i)dist



10

• Network Topology

1 2

3

4

5

6

Candidate node

Alive node

1 1

1

0.5 12

2

2

3

3

2 33

23

1

22

C

A

B


• Node density of each candidate node


11

1 2

3

4

5

6

Candidate node

Alive node

1 1

1

0.51

1

A

B

C


After the calculation of the node density of each candidate node, we use the following cost function to select CH

where N is the number of neighbor of the candidate node j S is a set of candidate nodes, is the square distance between node i and node j FD refers to the density factor which is the node density of a candidate node


12

s

N

i

DF

Sjjidist1

2 )|),(min(f(S)


We calculate for CH set selection

Where


13

Pd

)(`)(

)(`)(1

/))(`)((SfSfe

SfSfPddSfSf

20/1000 dd e

||`

SS

DFDFd


• Isolated node assisted phase


14

Sink

Cluster head

Cluster member

Isolated node

Mobile agent


• Steady phase

The mobile agent needs to move forward and back between its CH and isolated node for data collecting


15

Cluster head

Cluster member

Isolated node

Mobile agent


The CH periodically broadcasts a request-reply message for its mobile agent members to checks if all the mobile agents are back in the cluster

When all mobile agents are back, CH broadcasts a data-collection message for all its mobile agents to request them for collecting data from their neighbors

After mobile agent collects data from its neighbors and performs data aggregation, the mobile agent transmits its data to the CH

CH schedules all the members which has not transmitted its data and broadcasts a TDMA scheduling message for all these members


16


• Cross-CHs route construction phase

If there is any isolated node in a direction to the sink, CH selects the isolated node to be a gateway

If there is more than one isolated node in the direction to the sink, the CH chooses the isolated node whose corresponding mobile agent has highest energy level as a gateway

If there is no isolated in the direction to the sink, the CH needs to select a proper gateway to relay data to the sink

CH multicast gateway-selection message to those cluster member it the direction to the sink

These members independently starts a backoff timer to send a CatewayClaim message to its CH


17


18


We define the normalized hop cost from CH1 to CH2 through node A

where v is the immediate neighbor of node A which belong to is ClusterDegree of a cluster member A as the number of different clusters its immediate neighbor nodes belong to the residual energy level of node v Let denotes the average normalized hop cost from CH1 to CH2

that can be accessed through node A

)}(max{)()deg(

1),,( 21 vRE

AREACCHCHANhc

2CH

)deg(AC

)(vRE

)(aAhc

)(

),,()( 21

ARE

CHCHANAA hc

hc


19


Let denotes the backoff delay for a cluster member a

where is a time slot unit returns a random value between 0 and which is used to reduce the potential simultaneous transmission

abackoffT

),0()( AAT hca

backoff

),0(


20


• Gateway selection

CH1

CH2

CH3{3}

{1,3}

{1,2}

{3}

{2}

A

Cluster head

Cluster member

Gateway

Mobile agent

B

F

E

CD


21


CHs start to transmit their data to the sink by the well-established path They will piggyback the energy level of nodes within their cluster into

the transmitted data to the sink The sink will check whether the is less than If true, the sink recalculates the optimal set of CHs and broadcasts the beacon message to announce the starting of next round

S

RE2

initialS



• Flowchart of node behavior in each round

22

Selected to be a CH

Broadcast a link-request message and wait for link-assist

message

Yes

No

YesNo

Reply cluster-join and join the cluster

Receive a cluster-invite message

Join a cluster and transmit its data to

mobile agent

Be a gateway and relay data between

clusters

Broadcast a cluster-invite message and wait for cluster join

message

Broadcast TDMA scheduling and

receive data for its cluster member

Perform data aggregation and

construct cross-CH route

Receive a link-request messageYes

Become mobile agent and move forward to the

isolated node for data collection

Perform data aggregation and send the data on assigned timeslot

Wait for TDMA scheduling message

and sent its data on an assign timeslot

No

Selected to be a gateway

Yes

No

End

Wait for beacon message

Start

First round

Yes

No2

SRE initial

S Perform the same task as

last round

Yes

No


23

Performance evaluation - metrics (1/4)

• Simulation parameter [1,3,4]

Parameter Scenario A Scenario B

Network size 100 x 100 200 x 200

Transmission range 15 m 20 m

Number of Cluster Head 5 6

Channel mode TwoRayGround

Data size 25 bytes

Packet size 5 bytes

Packet arrival rate Randomly choose from [0,6]

Initial energy 2 J

MAC Protocol IEEE 802.15.4

Sensor nodes 100


24


• Simulation parameter [1,3,4]

Parameter Scenario A Scenario B

Speed of mobile agent 0.25 m/s

Simulation round 100

Transmitter circuitry dissipation per bit for normal node (Eelec)

50 nJ/bit

Transmitter amplifier dissipation per bit per square meter (εamp )

10 pJ/bit/m2

Circuit dissipation per bit for mobile agent (Eelec_mobile)

0.05 J/m

Circuit dissipation per bit for data aggregation (Eelec_aggregation)

3 nJ/bit

Horizontal and vertical distances between two adjacent nodes

20m


• Energy consumption model [5]

),(amplifier er transmitt the

and )(circuitry er transmitt the

todue distance aover message bitssmit tran

tonode ofn consumptioenergy thedenotes: ),(

dkE

kE

d k

dkE

ampTx

elecTx

Tx

2

),()(),(

dkkE

dkEkEdkE

ampelec

ampTxelecTxTx


25


)(circuitry er transmitt the todue message bits

receive tonode a ofn consumptioenergy therepresents : )(

kEk

kE

elecRx

Rx

kEkEkE elecelecRxRx )()(


• Control message transmission - the total number of control message transmissions to

establish the routes to the sink

• Broadcasting transmission- the total number of transmissions when a source CH

broadcasts a single packet to the sink

26


27

Performance evaluation - simulation results (1/6)

• Control message transmission with respect to Network Size

100X100 200X2000

500

1000

1500

2000

2500

3000

ERMC (proposed)

CBCDACP

Network Size

Co

ntr

ol M

es

sa

ge

Tra

ns

mis

sio

n


28


• Control message transmission with respect to Cluster Size

5 60

500

1000

1500

2000

2500

3000

ERMC (proposed)

CBCDACP

Cluster Size

Co

ntr

ol M

es

sa

ge

Tra

ns

mis

sio

n


29


• Broadcasting transmission with respect to Network Size

100X100 200X2000

500

1000

1500

2000

2500

ERMC (proposed)

CBCDACP

Network Size

Bro

ad

ca

sti

ng

Tra

ns

mis

sio

n


30


• Broadcasting transmission with respect to Cluster Size

5 60

500

1000

1500

2000

2500

ERMC (proposed)

CBCDACP

Cluster Size

Bro

ad

ca

sti

ng

Tra

ns

mis

sio

n


31

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 960

10

20

30

40

50

60

70

80

90

100

ERMC (proposed)

CBCDACP

Round time

Nu

mb

er

of

no

de

s a

live


• Number of nodes alive


32


• Energy dissipation per round

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 960

20

40

60

80

100

120

140

160

180

200

ERMC (proposed)

CBCDACP

Round time

En

erg

y D

iss

ipa

tio

n


Conclusion

• Conclusion

Proposed an energy-efficient and reliable multi-hop cluster- based (ERMC) WSNs

Using node density and minimum distance between CHs with their neighbors as the metrics to choose CHs, exploiting mobile agent to solve isolated node problem, and utilizing the node mobile agent saved as a gateway or using an energy-efficient mechanism to select gateway to relay data to the sink effectively, ERMC has the following benefits:

1. Its control message transmission is 61.33% lower than CBCDACP

2. Its broadcasting transmission is 68.18% lower than CBCDACP 33


References

[1] Yun-Sheng Yen; Ruay-Shiung Chang; Sin-Lung Ke; "An Energy-Efficient Clustering Protocol for Wireless Sensor Networks," Computer and Network Technology (ICCNT), 2010 Second International Conference on , pp.18-22, 23- 25 April 2010.[2] A. A. Abbasi and M. Younis, “A survey on clustering algorithms forwireless sensor networks,” Computer Communications, vol. 30, no. 14-15, pp. 2826– 2841, 2007.

[3] Jannatul Ferdous, M.; Ferdous, J.; Dey, T.; "Central Base-Station Controlled Density Aware Clustering Protocol for wireless sensor networks," Computers and Information Technology, 2009. ICCIT '09. 12th International Conference on, pp.37-43, 21-23 Dec. 2009.

[4] Long Cheng; Das, S.K.; Di Francesco, M.; Canfeng Chen; Jian Ma; "Scalable and Energy-Efficient Broadcasting in Multi-Hop Cluster-Based Wireless Sensor Networks," Communications (ICC), 2011 IEEE International Conference on , pp.1-5, 5-9 June 2011.

[5] Heinzelman, W.B.; Chandrakasan, A.P.; Balakrishnan, H.; , "An application-specific protocol architecture for wireless microsensor networks," Wireless Communications, IEEE Transactions on , vol.1, no.4, pp. 660- 670, Oct 2002.

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an energy-efficient and reliable multi-hop cluster-based wireless sensor networks

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