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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 - PowerPoint PPT Presentation
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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
Copyright © 2010, [email protected]
Outline
• Introduction• Related work• Proposed energy-efficient and reliable multi-hop cluster-based
(ERMC) WSNs• Performance evaluation
– Evaluation metrics– Simulation results
• Conclusion • References
2
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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]
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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]
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Introduction (3/3)
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• 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
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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
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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
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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
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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
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))(...(2)(1)min( )( PdistdistdistXNeighbor
(i)dist
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Proposed EMC-MAC protocol (4/16)
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• 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
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• Node density of each candidate node
Proposed EMC-MAC protocol (5/16)
11
1 2
3
4
5
6
Candidate node
Alive node
1 1
1
0.51
1
A
B
C
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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
Proposed EMC-MAC protocol (6/16)
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s
N
i
DF
Sjjidist1
2 )|),(min(f(S)
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We calculate for CH set selection
Where
Proposed EMC-MAC protocol (7/16)
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Pd
)(`)(
)(`)(1
/))(`)((SfSfe
SfSfPddSfSf
20/1000 dd e
||`
SS
DFDFd
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• Isolated node assisted phase
Proposed EMC-MAC protocol (8/16)
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Sink
Cluster head
Cluster member
Isolated node
Mobile agent
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• Steady phase
The mobile agent needs to move forward and back between its CH and isolated node for data collecting
Proposed EMC-MAC protocol (9/16)
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Cluster head
Cluster member
Isolated node
Mobile agent
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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
Proposed EMC-MAC protocol (10/16)
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• 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
Proposed EMC-MAC protocol (11/16)
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Proposed EMC-MAC protocol (12/16)
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
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Proposed EMC-MAC protocol (13/16)
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(
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Proposed EMC-MAC protocol (14/16)
• Gateway selection
CH1
CH2
CH3{3}
{1,3}
{1,2}
{3}
{2}
A
Cluster head
Cluster member
Gateway
Mobile agent
B
F
E
CD
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21
Proposed EMC-MAC protocol (15/16)
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
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Proposed EMC-MAC protocol (16/16)
• Flowchart of node behavior in each round
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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
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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
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Performance evaluation - metrics (2/4)
• 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
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• 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
Performance evaluation - metrics (3/4)
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Copyright © 2010, [email protected]
)(circuitry er transmitt the todue message bits
receive tonode a ofn consumptioenergy therepresents : )(
kEk
kE
elecRx
Rx
kEkEkE elecelecRxRx )()(
Performance evaluation - metrics (4/4)
• 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
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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
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Performance evaluation - simulation results (2/6)
• 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
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29
Performance evaluation - simulation results (3/6)
• 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
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30
Performance evaluation - simulation results (4/6)
• 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
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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
Performance evaluation - simulation results (5/6)
• Number of nodes alive
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32
Performance evaluation - simulation results (6/6)
• 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
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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
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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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