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Multipath Routing in WSN with multiple Sink nodes
YUEQUAN CHEN, Edward Chan and Song Han
Department of Computer Science
City University of HongKong
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Outline
• Issues of energy consumption in WSN
• Architecture of Multiple Sink
• Main Idea in MRMS
• MRMS protocol description
• Experimental Results
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Issue in Energy Consumption of WSN
• Sensors near the sink nodes will dissipate energy faster than other sensors
• How to scale the network size
Solution: Deploying multiple Sink nodes in WSN is one of best choice.
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Main Idea in MRMS (cont)
• Cluster Maintenance– Energy monitoring
– Cluster reconstruction
• Path Switching– Patch Switching based on path cost
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MRMS protocol description- Topology Discovery
Before Topology Discovery
After Topology Discovery
S
S
S
sensor node
S Sink node
S
S
S
undiscovered sensor
S Sink node
cluster head
onecluster
cluster children
multi-hoppath
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Topology Discovery
• Topology Discovery is based on three-color algorithm
• The cluster is stateless
• The metric of constructing the cluster is based on path_cost using Dijstra algorithm
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MRMS protocol description - Intra-Cluster Reconstruction
0.12
0.23
0.19
0.32
0.08
RE RE: residual energy
Old CH
BroadcastSELECT NEW CH
0.12
0.23
0.19
0.32
0.08
RE RE: residual energy
Old CH
Maximum ResidualEnergy node
(a) Broadcast SELECT_NEW_CH
(b) Select Maximum Residual Energy node
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MRMS protocol description- Intra-Cluster Reconstruction
(c) Broadcast NEW_CH (d) New Cluster after re-construction
0.03
0.12
0.23
0.19
0.32
0.08
RERE: residual
energy
Old CH
BroadcastNEW CH
Maximum ResidualEnergy node
0.03
0.12
0.23
0.19
0.32
0.08
RE RE: residualenergy
New CH
Point to NewCH
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MRMS protocol description- Inter-Cluster Reconstruction
(a) Before change delivery node
(b) After change delivery node
S0.012
0.002
0.003 CH
Old deliverynode
0.010
0.004
0.011One hop
cost
Path_cost Multi-hopspath
S0.012
0.002
0.003 CH
New deliverynode
0.010
0.004
0.011One hop
cost
Path_cost Multi-hopspath
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Cluster Reconstruction
• Cluster Header monitors its energy periodically
• In the intra-cluster reconstructing, select the max residual energy as new cluster head
• In the inter-cluster reconstructing, select the node whose path_cost to sink is min as new delivery node.
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MRMS protocol description- Path Switching
(a) Before path switching (b) After path switching
S3 S1
AC
0.52
0.08
cost primarypath
Deliver Node ofprimary path
CH
S2
B
0.32 0.40
0.10 0.12
costAlternative
pathpath_cost Multi-hops
path
S3 S1
AC
0.52
0.08
cost primarypath
Deliver Node ofprimary path
CH
S2
B
0.32 0.40
0.10 0.12
costAlternative
pathpath_cost Multi-hops
path
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Path Switching
• Using event-based approach to trigger the path switching, not periodical update approach
• Select the min path_cost to other sink node as new path.
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Experimental Results
Time to First Node Failure
0
200
400
600
800
1000
1200
Ti me (s)
Di rectFl oodi ngTopDi scAl gori thmVoronoiAl gori thmMRMS